Rolling bearings — Damage and failures — Terms, characteristics and causes

ISO 15243:2017 classifies different modes of failure occurring in service for rolling bearings made of standard bearing steels. For each failure mode, it defines and describes the characteristics, appearance and possible root causes of failure. It will assist in the identification of failure modes based on appearance. For the purposes of this document, the following terms are explained: - failure of a rolling bearing: the result of a damage that prevents the bearing meeting the intended design performance or marks the end of service life; - in service: as soon as the bearing has left the manufacturer's factory; - visible features: those that are possible to observe directly or with magnifiers or optical microscopes, also those from pictures, but only with the use of non-destructive methods. Consideration is restricted to characteristic forms of change in appearance and failure that have well-defined appearance and which can be attributed to particular causes with a high degree of certainty. The features of particular interest for explaining changes and failures are described. The various forms are illustrated with photographs and the most frequent causes are indicated. If the root cause cannot be reliably assessed by the examination and characterization of visual features against the information in this document, then additional investigations are to be considered. These methods are summarized in A.3 and may involve, for example, the use of invasive methods possibly including taking of cross sections, metallurgical structural analysis by visual and electronic microscopes, chemical and spectrographic analysis. These specialized methods are outside the scope of this document. The failure mode terms shown in the subclause titles are recommended for general use. Where appropriate, alternative expressions or synonyms used to describe the submodes are given and explained in A.4. Examples of rolling bearing failures are given in A.2, together with a description of the causes of failure and proposed corrective actions.

Roulements — Détérioration et défaillance — Termes, caractéristiques et causes

ISO 15243:2017 classe les différents modes de défaillance survenant en cours de fonctionnement pour les roulements en aciers standards. Elle définit et décrit, pour chaque mode de défaillance, les caractéristiques, l'aspect et les possibles causes racines de la défaillance. Elle contribuera à l'identification des modes de défaillance en s'appuyant sur l'aspect. Les termes suivants sont expliqués pour les besoins du présent document: - défaillance d'un roulement: résultat d'une détérioration qui empêche le roulement de satisfaire à ses performances initialement prévues ou marque la fin de sa durée de vie; - en service: état du roulement tel qu'il sort de l'usine du fabricant; - caractéristiques visibles: caractéristiques qu'il est possible d'observer directement ou avec une loupe ou un microscope optique, ainsi que celles observées sur des images, mais en utilisant uniquement des méthodes non destructives. L'analyse se limite aux formes caractéristiques du changement d'aspect et aux défaillances ayant un aspect bien défini et pouvant être imputables à des causes particulières avec un degré de certitude élevé. Les caractéristiques d'intérêt particulier relatives à l'explication des changements et des défaillances sont décrites. Les formes diverses sont illustrées par des photographies et les causes les plus fréquentes sont indiquées. Si la cause racine ne peut pas être évaluée de manière fiable par l'examen et la description des caractéristiques visuelles confrontés aux informations fournies dans le présent document, des examens complémentaires sont à envisager. Ces méthodes sont résumées au A.3 et peuvent impliquer, par exemple, l'utilisation de méthodes invasives pouvant inclure le prélèvement de coupes transversales, des analyses métallurgiques structurelles au moyen de microscopes visuels ou électroniques et des analyses chimiques et spectrographiques. Ces méthodes spécialisées ne sont pas incluses dans le domaine d'application du présent document. Les termes des modes de défaillance exprimés dans les titres des paragraphes sont recommandés pour un usage général. Le cas échéant, les expressions alternatives ou synonymes utilisés pour décrire les sous-modes sont indiqués et expliqués en A.4. Des exemples de défaillances des roulements, accompagnés d'une description des causes de la défaillance et des mesures correctives proposées, sont donnés en A.2.

Kotalni ležaji - Poškodbe in napake - Izrazi, karakteristike in vzroki

General Information

Status
Published
Publication Date
09-Apr-2017
Current Stage
9093 - International Standard confirmed
Completion Date
19-Dec-2022

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INTERNATIONAL ISO
STANDARD 15243
Second edition
2017-03
Rolling bearings — Damage and
failures — Terms, characteristics and
causes
Roulements — Détérioration et défaillance — Termes,
caractéristiques et causes
Reference number
ISO 15243:2017(E)
ISO 2017
---------------------- Page: 1 ----------------------
ISO 15243:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 15243:2017(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Classification of failure modes occurring in rolling bearings ............................................................................... 2

5 Failure modes .......................................................................................................................................................................................................... 3

5.1 Rolling contact fatigue ...................................................................................................................................................................... 3

5.1.1 General description of rolling contact fatigue ........................................................................................ 3

5.1.2 Subsurface initiated fatigue .................................................................................................................................... 4

5.1.3 Surface initiated fatigue ............................................................................................................................................. 4

5.2 Wear ................................................................................................................................................................................................................. 6

5.2.1 General description of wear ................................................................................................................................... 6

5.2.2 Abrasive wear ..................................................................................................................................................................... 6

5.2.3 Adhesive wear .................................................................................................................................................................... 7

5.3 Corrosion ..................................................................................................................................................................................................... 9

5.3.1 General description of corrosion ....................................................................................................................... 9

5.3.2 Moisture corrosion......................................................................................................................................................... 9

5.3.3 Frictional corrosion ....................................................................................................................................................10

5.4 Electrical erosion ...............................................................................................................................................................................12

5.4.1 General description of electrical erosion .................................................................................................12

5.4.2 Excessive current erosion .....................................................................................................................................12

5.4.3 Current leakage erosion .........................................................................................................................................13

5.5 Plastic deformation ..........................................................................................................................................................................14

5.5.1 General description of plastic deformation ...........................................................................................14

5.5.2 Overload deformation ..............................................................................................................................................14

5.5.3 Indentations from particles .................................................................................................................................16

5.6 Cracking and fracture .....................................................................................................................................................................17

5.6.1 General description of cracking and fracture .......................................................................................17

5.6.2 Forced fracture ...............................................................................................................................................................17

5.6.3 Fatigue fracture ..............................................................................................................................................................18

5.6.4 Thermal cracking ..........................................................................................................................................................19

Annex A (informative) Failure analysis — Illustrations of damage — Other investigations

— Explanation of terms used................................................................................................................................................................20

Bibliography .............................................................................................................................................................................................................................53

© ISO 2017 – All rights reserved iii
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ISO 15243:2017(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,

as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the

Technical Barriers to Trade (TBT) see the following URL: www . i so .org/ iso/ foreword .html.

The committee responsible for this document is ISO/TC 4, Rolling bearings.

This second edition cancels and replaces the first edition (ISO 15243:2004), which has been technically

revised.
iv © ISO 2017 – All rights reserved
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ISO 15243:2017(E)
Introduction

In practice, damage and/or failure of a rolling bearing can often be the result of several mechanisms

operating simultaneously. The failure can result from improper transport, handling, mounting or

maintenance or from faulty manufacture of the bearing or its adjacent parts. In some instances, failure

is due to a design compromise made in the interests of economy or from unforeseen operating and

environmental conditions. It is the complex combination of design, manufacture, mounting, operation

and maintenance that often causes difficulty in establishing the root cause of failure.

NOTE Be aware that counterfeit bearings are circulated in the market. They might look as original bearings,

but their use often lead to very early damage or failure.

In the event of extensive damage to or catastrophic failure of the bearing, the evidence is likely to be

lost and it will then be impossible to identify the root cause of failure. It is therefore important to stop

equipment in time to enable appropriate bearing damage analysis (see Figure 1). In all cases, knowledge

of the actual operating conditions of the assembly and the maintenance history is of utmost importance.

NOTE The spall started just behind the dent in the raceway [a)]. Over a period of time, the spalling becomes

more severe [b) and c)]. If not stopped in time, the proof of the root cause disappears [d)].

Figure 1 — Progression of bearing damage

The classification of bearing failure established in this document is based primarily upon the features

visible on rolling contact surfaces and other functional surfaces. Consideration of each feature is

required for reliable determination of the root cause of bearing failure. Since more than one failure

mechanism may cause similar effects to these surfaces, a description of appearance alone is often

inadequate for determining the cause of the failure. In such cases, the operating conditions need to be

considered. In some cases, the analysed damage is too advanced, and can be originated from different

primary causes. In these cases, it is interesting to look for simultaneous presence of indications to

determine the primary cause of the failure.

This document covers rolling bearings having steel rings and rolling elements. Damage to the rings of

bearings with ceramic rolling elements shows similar failure modes.
[1]

In this document, bearing life is as described in ISO 281 , which provides formulae to calculate bearing

life taking a number of factors into consideration, such as bearing load carrying capacity, bearing load,

type of bearing, material, bearing fatigue load limit, lubrication conditions and degree of contamination.

© ISO 2017 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 15243:2017(E)
Rolling bearings — Damage and failures — Terms,
characteristics and causes
1 Scope

This document classifies different modes of failure occurring in service for rolling bearings made of

standard bearing steels. For each failure mode, it defines and describes the characteristics, appearance

and possible root causes of failure. It will assist in the identification of failure modes based on

appearance.
For the purposes of this document, the following terms are explained:

— failure of a rolling bearing: the result of a damage that prevents the bearing meeting the intended

design performance or marks the end of service life;
— in service: as soon as the bearing has left the manufacturer’s factory;

— visible features: those that are possible to observe directly or with magnifiers or optical microscopes,

also those from pictures, but only with the use of non-destructive methods.

Consideration is restricted to characteristic forms of change in appearance and failure that have well-

defined appearance and which can be attributed to particular causes with a high degree of certainty.

The features of particular interest for explaining changes and failures are described. The various forms

are illustrated with photographs and the most frequent causes are indicated.

If the root cause cannot be reliably assessed by the examination and characterization of visual

features against the information in this document, then additional investigations are to be considered.

These methods are summarized in A.3 and may involve, for example, the use of invasive methods

possibly including taking of cross sections, metallurgical structural analysis by visual and electronic

microscopes, chemical and spectrographic analysis. These specialized methods are outside the scope of

this document.

The failure mode terms shown in the subclause titles are recommended for general use. Where

appropriate, alternative expressions or synonyms used to describe the submodes are given and

explained in A.4.

Examples of rolling bearing failures are given in A.2, together with a description of the causes of failure

and proposed corrective actions.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 5593, Rolling bearings — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5593 and the following apply.

NOTE Explanations for terms for damage and failures are listed in A.4.
© ISO 2017 – All rights reserved 1
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ISO 15243:2017(E)

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
characteristics
visual appearance that results from service performance
[3]

Note 1 to entry: Surface defects and types of geometrical change are defined in ISO 8785 and partly in

[2]
ISO 6601 (related to abrasive wear).
3.2
damage
any visible deterioration of the bearing operating surfaces or structures
3.3
event sequences

sequence of events leading to bearing failure (3.4) starting with initial damage (3.2) to the bearing

Note 1 to entry: At an early stage, this damage can result in loss of function or failure. In many cases, however,

the initial damage does not result in failure and the bearing continues to operate. This continued operation most

often leads to secondary damage which eventually results in failure. Secondary damage can introduce competing

modes of failure, which can make root cause analysis difficult.
3.4
failure
any condition where the bearing can no longer deliver its designed function

Note 1 to entry: This will include degradation of important rotational properties and warning of imminent

more extensive or complete failure, but may not be so advanced as to prevent rotation or support of the subject

machine elements.

Note 2 to entry: The extent of damage (3.2) required to cause a declaration of operational failure will depend on

the application. Applications requiring accurate smooth rotation will tolerate only very minor loss of properties.

Applications not sensitive to increased vibration, increased noise or reduced rotational accuracy may be able to

continue to deliver their performance for a restricted period.
3.5
failure mode
manner in which a bearing fails
4 Classification of failure modes occurring in rolling bearings

Preferably, one would classify rolling bearing damage and failures according to the root cause. However,

it is often not easy to distinguish between causes and characteristics (symptoms) or, in other words,

between failure mechanisms and failure modes. The large number of articles and books written on the

subject confirms this (see Bibliography). Therefore, in this document, failure modes are classified in

six main groups and various sub-groups (see Figure 2), based on their visible distinctive characteristic

appearance in service.
2 © ISO 2017 – All rights reserved
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ISO 15243:2017(E)
Figure 2 — Classification of failure modes
5 Failure modes
5.1 Rolling contact fatigue
5.1.1 General description of rolling contact fatigue

Rolling contact fatigue is caused by the repeated stresses developed in the contacts between the rolling

elements and the raceways. Fatigue is manifested visibly as a change in the structure (microstructure)

© ISO 2017 – All rights reserved 3
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ISO 15243:2017(E)

and as spalling of material from the surface (macrostructure) that, in most of the cases, could be

consequential to a change in microstructure.
NOTE Spalling and flaking are synonyms (see A.4).
5.1.2 Subsurface initiated fatigue

Under the influence of cyclic loading in the rolling contacts described by the Hertzian theory,

stresses and material structural changes occur and microcracks are initiated at a location and depth

which depend on the applied load, the operating temperature, the material and its cleanliness and

microstructure. The initiation of the microcracks is often caused by inclusions in the bearing steel.

The changes might appear at metallurgical investigation (see A.3). These cracks propagate and when

they come to the surface, spalling occurs (see Figures 3 and 4).

Figure 3 — Initial subsurface spalling in a deep groove ball bearing — Rotating inner ring

Figure 4 — Advanced subsurface spalling in a tapered roller bearing — Stationary inner ring

5.1.3 Surface initiated fatigue
Fatigue initiated from the surface is typically caused by surface distress.

Surface distress is damage initiated at the rolling contact surfaces due to plastic deformation of the

surface asperities (smoothing, burnishing, glazing). Contact between the asperities of the rolling

element and bearing raceway is most often the result of inadequate lubrication conditions (insufficient

lubricant film thickness). This contact may be caused by insufficient lubrication flow/availability,

improper lubricant for the application, operating temperatures beyond the expected level or rough

surface finishes. Contact and plastic deformation of the surface asperities can lead to

— asperity microcracks (see Figure 5),
— asperity microspalls (see Figure 6), and
4 © ISO 2017 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 15243:2017(E)
— microspalled areas (grey stained) (see Figure 7).

Sliding motion under low lubricant film conditions can significantly accelerate the surface damage.

For cases where film thickness is sufficient for normal operating conditions, surface-initiated fatigue

may still occur. This can happen when particles are introduced into the contact area (see 5.5.3),

extreme loads plastically deform the surface or handling nicks are present. All three conditions result

in indentations in the raceways. Protrusions around the indentation exceed the height of the oil film,

resulting in deformation of surface asperities. Surface initiated fatigue caused by indentation arising

from plastic deformation is shown in A.2.6.2.
[1]

NOTE ISO 281 includes surface related calculation parameters that are known to have an influence on the

bearing life such as material, lubrication, environment, contamination particles and bearing load.

Figure 5 — Asperity microcracks and microspalls on a raceway
Figure 6 — Surface initiated microspalls on a raceway
© ISO 2017 – All rights reserved 5
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ISO 15243:2017(E)
Figure 7 — Microspalled areas on a raceway
5.2 Wear
5.2.1 General description of wear

Wear is the progressive removal of material from the surface, resulting from the interaction of two

sliding or rolling/sliding contacting surfaces during service.
5.2.2 Abrasive wear

Abrasive wear (particle wear, three-body wear) is the removal of material due to sliding in presence

of hard particles. It is the result of a hard surface or particle removing material from another surface

through a cutting or ploughing action when sliding across it. The surfaces become dull to a degree, which

varies according to the coarseness and nature of the abrasive particles (see Figure 8). These particles

gradually increase in number as material is worn away from the running surfaces and, possibly, the

cage (see Figure 9). Finally, the wear becomes an accelerating process that results in a failed bearing.

Although the surfaces normally become dull to a certain extent, when the abrasive particles are very

fine, a polishing effect might occur, resulting in very shiny surfaces (see Figure 10).

NOTE The “running-in” of a rolling bearing is a natural short process after which the running behaviour,

e.g. noise or operating temperature, stabilizes or even improves. As a consequence, the running path or running

track becomes visible; however this is not indicating that the bearing is damaged.

6 © ISO 2017 – All rights reserved
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ISO 15243:2017(E)
Figure 8 — Abrasive wear on the inner ring of a spherical roller bearing
Figure 9 — Advanced abrasive wear on the cage pockets of a solid metal cage

Figure 10 — Abrasive wear on the raceway of the large rib surface of the inner ring and on the

large end face of rollers in a tapered roller bearing
5.2.3 Adhesive wear

Adhesive wear is characterized by a transfer of material from one surface to another with frictional heat

and, sometimes, tempering or rehardening of the surface. This produces localized stress concentrations

with the potential for cracking or spalling of the contact areas.

Smearing (skidding, galling, scoring, frosting) occurs because of inadequate lubrication conditions

when sliding occurs and localized temperature rises from friction cause adhesion of the contacting

surfaces, resulting in material transfer. This typically happens between rolling elements and raceways

if the rolling elements are too lightly loaded and subjected to severe acceleration on their re-entry

into the load zone (see Figures 11 and 12). In severe cases of smearing, seizing may result. Smearing is

usually a sudden occurrence as opposed to an accumulated wear process.
© ISO 2017 – All rights reserved 7
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ISO 15243:2017(E)

Smearing can also occur on the rib faces and on the ends of the rollers due to inadequate lubrication (see

Figure 13). In full complement (cageless) bearings, smearing can also occur in the contacts between

rolling elements, depending on lubrication and rotation conditions.

If a bearing ring moves (creeps) relative to its seat because of inadequate retention on the shaft or in

the housing, then smearing (also called scuffing) can occur in the bearing bore, the outside diameter

or on the shaft or in the housing seat. Because of the minute difference in the diameters of the two

components, they will have a minute difference in their circumferences and, consequently, when

brought into contact at successive points by the radial load rotating with respect to the ring, will rotate

at minutely different speeds. This rolling motion of the ring against its seating with a minute difference

in the rotational speeds is termed “creep”.

When creep occurs, the asperities in the ring/seat contact region are over-rolled, which can cause the

surface of the ring to take on a shiny appearance. The over-rolling during creeping is often, but not

always, accompanied by sliding in the ring/seat contact, and then other damage will also be visible, e.g.

score marks, fretting corrosion and wear. Under certain loading conditions and when the ring/seating

interference fit is insufficiently tight, fretting corrosion will predominate (see A.2.4.2.1 and A.2.4.2.2).

Furthermore, with a loose radial fit, creep can also occur between the face of a ring and its axial

abutment. In severe cases, this can lead to transverse thermal cracks and finally cause cracking of the

ring (see 5.6.4).
Figure 11 — Smearing on the outer ring raceway of a cylindrical roller bearing
Figure 12 — Smearing on the outer ring raceways of a spherical roller bearing
8 © ISO 2017 – All rights reserved
---------------------- Page: 13 ----------------------
ISO 15243:2017(E)
Figure 13 — Smearing on the side face of rollers of a cylindrical roller bearing
5.3 Corrosion
5.3.1 General description of corrosion
Corrosion is the result of a chemical reaction on metal surfaces.
5.3.2 Moisture corrosion

When bearing components are in contact with moisture or aggressive media (e.g. water or acids),

oxidation or corrosion (rust) of surfaces takes place (see Figure 14). Subsequently, the formation of

corrosion pits occurs and finally spalling of the surface occurs (see Figure 15).

A specific form of moisture corrosion can be observed in the contact areas between rolling elements

and bearing rings where the water content in the lubricant or the degraded lubricant reacts with the

surfaces of the adjacent bearing elements. During static periods, the advanced stage will result in dark

discolouration of the contact areas at intervals corresponding to the ball/roller pitch (see Figure 16);

eventually producing corrosion pits.

Figure 14 — Moisture corrosion on the cage and rollers of a needle roller thrust bearing

Figure 15 — Moisture corrosion on the outer ring raceway of a cylindrical roller bearing

© ISO 2017 – All rights reserved 9
---------------------- Page: 14 ----------------------
ISO 15243:2017(E)

Figure 16 — Contact corrosion at roller pitch on the inner ring raceway of a tapered roller bearing

5.3.3 Frictional corrosion
5.3.3.1 General description of frictional corrosion

Frictional corrosion (tribo-corrosion, tribo-oxidation) is a chemical reaction activated by relative

micromovements between mating surfaces under certain friction and load conditions. These

micromovements lead to oxidation of the surfaces and released material becoming visible as powdery

rust and/or loss of material from one or both mating surfaces.
5.3.3.2 Fretting corrosion

Fretting corrosion occurs in fit interfaces between components that are transmitting loads under

oscillating contact surface micromovements. Surface asperities oxidize and are rubbed off and vice

versa; powdery rust develops (fretting rust, iron oxide). The bearing surface becomes discoloured

blackish red (see Figure 17). Typically, the damage develops when loads and/or vibrations overcome

the radial clamping given by the mounting fits. Excessively rough and/or wavy surface finish of bearing,

shaft and housing surfaces can also reduce the effective mounting fit and induce fretting corrosion (see

Figure 18).

NOTE 1 Some abrasive wear might occur as a resultant effect of the presence of the corrosion products (iron

oxide) and micromovements.

NOTE 2 In this document, fretting corrosion is classified under corrosion. In other documents, it is sometimes

classified as fretting wear.

Figure 17 — Fretting corrosion in the inner ring bore of a deep groove ball bearing

10 © ISO 2017 – All rights reserved
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ISO 15243:2017(E)
Figure 18 — Fretting corrosion on the outer diameter of a roller bearing
5.3.3.3 False brinelling

False brinelling (vibration corrosion) most commonly occurs in rolling element/raceway contact areas

of non-rotating bearings due to micromovements and/or resilience of the elastic contacts under cyclic

vibrations. Depending on the intensity of the vibrations, the load and lubrication conditions, depressions

are formed on the raceways, mostly also leading to corrosion (due to lack of protective lubricant) and

resultantly abrasive wear.

In the case of a stationary bearing, the depressions appear at rolling element pitch and may be

discoloured reddish or shiny (see Figures 19 and 20).
False brinelling occurring in stand-by equipment, when long stopped p
...

SLOVENSKI STANDARD
SIST ISO 15243:2020
01-maj-2020
Kotalni ležaji - Poškodbe in napake - Izrazi, karakteristike in vzroki
Rolling bearings - Damage and failures - Terms, characteristics and causes
Roulements - Détérioration et défaillance - Termes, caractéristiques et causes
Ta slovenski standard je istoveten z: ISO 15243:2017
ICS:
21.100.20 Kotalni ležaji Rolling bearings
SIST ISO 15243:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST ISO 15243:2020
---------------------- Page: 2 ----------------------
SIST ISO 15243:2020
INTERNATIONAL ISO
STANDARD 15243
Second edition
2017-03
Rolling bearings — Damage and
failures — Terms, characteristics and
causes
Roulements — Détérioration et défaillance — Termes,
caractéristiques et causes
Reference number
ISO 15243:2017(E)
ISO 2017
---------------------- Page: 3 ----------------------
SIST ISO 15243:2020
ISO 15243:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form

or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior

written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of

the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 15243:2020
ISO 15243:2017(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Classification of failure modes occurring in rolling bearings ............................................................................... 2

5 Failure modes .......................................................................................................................................................................................................... 3

5.1 Rolling contact fatigue ...................................................................................................................................................................... 3

5.1.1 General description of rolling contact fatigue ........................................................................................ 3

5.1.2 Subsurface initiated fatigue .................................................................................................................................... 4

5.1.3 Surface initiated fatigue ............................................................................................................................................. 4

5.2 Wear ................................................................................................................................................................................................................. 6

5.2.1 General description of wear ................................................................................................................................... 6

5.2.2 Abrasive wear ..................................................................................................................................................................... 6

5.2.3 Adhesive wear .................................................................................................................................................................... 7

5.3 Corrosion ..................................................................................................................................................................................................... 9

5.3.1 General description of corrosion ....................................................................................................................... 9

5.3.2 Moisture corrosion......................................................................................................................................................... 9

5.3.3 Frictional corrosion ....................................................................................................................................................10

5.4 Electrical erosion ...............................................................................................................................................................................12

5.4.1 General description of electrical erosion .................................................................................................12

5.4.2 Excessive current erosion .....................................................................................................................................12

5.4.3 Current leakage erosion .........................................................................................................................................13

5.5 Plastic deformation ..........................................................................................................................................................................14

5.5.1 General description of plastic deformation ...........................................................................................14

5.5.2 Overload deformation ..............................................................................................................................................14

5.5.3 Indentations from particles .................................................................................................................................16

5.6 Cracking and fracture .....................................................................................................................................................................17

5.6.1 General description of cracking and fracture .......................................................................................17

5.6.2 Forced fracture ...............................................................................................................................................................17

5.6.3 Fatigue fracture ..............................................................................................................................................................18

5.6.4 Thermal cracking ..........................................................................................................................................................19

Annex A (informative) Failure analysis — Illustrations of damage — Other investigations

— Explanation of terms used................................................................................................................................................................20

Bibliography .............................................................................................................................................................................................................................53

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Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,

as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the

Technical Barriers to Trade (TBT) see the following URL: www . i so .org/ iso/ foreword .html.

The committee responsible for this document is ISO/TC 4, Rolling bearings.

This second edition cancels and replaces the first edition (ISO 15243:2004), which has been technically

revised.
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Introduction

In practice, damage and/or failure of a rolling bearing can often be the result of several mechanisms

operating simultaneously. The failure can result from improper transport, handling, mounting or

maintenance or from faulty manufacture of the bearing or its adjacent parts. In some instances, failure

is due to a design compromise made in the interests of economy or from unforeseen operating and

environmental conditions. It is the complex combination of design, manufacture, mounting, operation

and maintenance that often causes difficulty in establishing the root cause of failure.

NOTE Be aware that counterfeit bearings are circulated in the market. They might look as original bearings,

but their use often lead to very early damage or failure.

In the event of extensive damage to or catastrophic failure of the bearing, the evidence is likely to be

lost and it will then be impossible to identify the root cause of failure. It is therefore important to stop

equipment in time to enable appropriate bearing damage analysis (see Figure 1). In all cases, knowledge

of the actual operating conditions of the assembly and the maintenance history is of utmost importance.

NOTE The spall started just behind the dent in the raceway [a)]. Over a period of time, the spalling becomes

more severe [b) and c)]. If not stopped in time, the proof of the root cause disappears [d)].

Figure 1 — Progression of bearing damage

The classification of bearing failure established in this document is based primarily upon the features

visible on rolling contact surfaces and other functional surfaces. Consideration of each feature is

required for reliable determination of the root cause of bearing failure. Since more than one failure

mechanism may cause similar effects to these surfaces, a description of appearance alone is often

inadequate for determining the cause of the failure. In such cases, the operating conditions need to be

considered. In some cases, the analysed damage is too advanced, and can be originated from different

primary causes. In these cases, it is interesting to look for simultaneous presence of indications to

determine the primary cause of the failure.

This document covers rolling bearings having steel rings and rolling elements. Damage to the rings of

bearings with ceramic rolling elements shows similar failure modes.
[1]

In this document, bearing life is as described in ISO 281 , which provides formulae to calculate bearing

life taking a number of factors into consideration, such as bearing load carrying capacity, bearing load,

type of bearing, material, bearing fatigue load limit, lubrication conditions and degree of contamination.

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INTERNATIONAL STANDARD ISO 15243:2017(E)
Rolling bearings — Damage and failures — Terms,
characteristics and causes
1 Scope

This document classifies different modes of failure occurring in service for rolling bearings made of

standard bearing steels. For each failure mode, it defines and describes the characteristics, appearance

and possible root causes of failure. It will assist in the identification of failure modes based on

appearance.
For the purposes of this document, the following terms are explained:

— failure of a rolling bearing: the result of a damage that prevents the bearing meeting the intended

design performance or marks the end of service life;
— in service: as soon as the bearing has left the manufacturer’s factory;

— visible features: those that are possible to observe directly or with magnifiers or optical microscopes,

also those from pictures, but only with the use of non-destructive methods.

Consideration is restricted to characteristic forms of change in appearance and failure that have well-

defined appearance and which can be attributed to particular causes with a high degree of certainty.

The features of particular interest for explaining changes and failures are described. The various forms

are illustrated with photographs and the most frequent causes are indicated.

If the root cause cannot be reliably assessed by the examination and characterization of visual

features against the information in this document, then additional investigations are to be considered.

These methods are summarized in A.3 and may involve, for example, the use of invasive methods

possibly including taking of cross sections, metallurgical structural analysis by visual and electronic

microscopes, chemical and spectrographic analysis. These specialized methods are outside the scope of

this document.

The failure mode terms shown in the subclause titles are recommended for general use. Where

appropriate, alternative expressions or synonyms used to describe the submodes are given and

explained in A.4.

Examples of rolling bearing failures are given in A.2, together with a description of the causes of failure

and proposed corrective actions.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 5593, Rolling bearings — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5593 and the following apply.

NOTE Explanations for terms for damage and failures are listed in A.4.
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ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
characteristics
visual appearance that results from service performance
[3]

Note 1 to entry: Surface defects and types of geometrical change are defined in ISO 8785 and partly in

[2]
ISO 6601 (related to abrasive wear).
3.2
damage
any visible deterioration of the bearing operating surfaces or structures
3.3
event sequences

sequence of events leading to bearing failure (3.4) starting with initial damage (3.2) to the bearing

Note 1 to entry: At an early stage, this damage can result in loss of function or failure. In many cases, however,

the initial damage does not result in failure and the bearing continues to operate. This continued operation most

often leads to secondary damage which eventually results in failure. Secondary damage can introduce competing

modes of failure, which can make root cause analysis difficult.
3.4
failure
any condition where the bearing can no longer deliver its designed function

Note 1 to entry: This will include degradation of important rotational properties and warning of imminent

more extensive or complete failure, but may not be so advanced as to prevent rotation or support of the subject

machine elements.

Note 2 to entry: The extent of damage (3.2) required to cause a declaration of operational failure will depend on

the application. Applications requiring accurate smooth rotation will tolerate only very minor loss of properties.

Applications not sensitive to increased vibration, increased noise or reduced rotational accuracy may be able to

continue to deliver their performance for a restricted period.
3.5
failure mode
manner in which a bearing fails
4 Classification of failure modes occurring in rolling bearings

Preferably, one would classify rolling bearing damage and failures according to the root cause. However,

it is often not easy to distinguish between causes and characteristics (symptoms) or, in other words,

between failure mechanisms and failure modes. The large number of articles and books written on the

subject confirms this (see Bibliography). Therefore, in this document, failure modes are classified in

six main groups and various sub-groups (see Figure 2), based on their visible distinctive characteristic

appearance in service.
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Figure 2 — Classification of failure modes
5 Failure modes
5.1 Rolling contact fatigue
5.1.1 General description of rolling contact fatigue

Rolling contact fatigue is caused by the repeated stresses developed in the contacts between the rolling

elements and the raceways. Fatigue is manifested visibly as a change in the structure (microstructure)

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and as spalling of material from the surface (macrostructure) that, in most of the cases, could be

consequential to a change in microstructure.
NOTE Spalling and flaking are synonyms (see A.4).
5.1.2 Subsurface initiated fatigue

Under the influence of cyclic loading in the rolling contacts described by the Hertzian theory,

stresses and material structural changes occur and microcracks are initiated at a location and depth

which depend on the applied load, the operating temperature, the material and its cleanliness and

microstructure. The initiation of the microcracks is often caused by inclusions in the bearing steel.

The changes might appear at metallurgical investigation (see A.3). These cracks propagate and when

they come to the surface, spalling occurs (see Figures 3 and 4).

Figure 3 — Initial subsurface spalling in a deep groove ball bearing — Rotating inner ring

Figure 4 — Advanced subsurface spalling in a tapered roller bearing — Stationary inner ring

5.1.3 Surface initiated fatigue
Fatigue initiated from the surface is typically caused by surface distress.

Surface distress is damage initiated at the rolling contact surfaces due to plastic deformation of the

surface asperities (smoothing, burnishing, glazing). Contact between the asperities of the rolling

element and bearing raceway is most often the result of inadequate lubrication conditions (insufficient

lubricant film thickness). This contact may be caused by insufficient lubrication flow/availability,

improper lubricant for the application, operating temperatures beyond the expected level or rough

surface finishes. Contact and plastic deformation of the surface asperities can lead to

— asperity microcracks (see Figure 5),
— asperity microspalls (see Figure 6), and
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— microspalled areas (grey stained) (see Figure 7).

Sliding motion under low lubricant film conditions can significantly accelerate the surface damage.

For cases where film thickness is sufficient for normal operating conditions, surface-initiated fatigue

may still occur. This can happen when particles are introduced into the contact area (see 5.5.3),

extreme loads plastically deform the surface or handling nicks are present. All three conditions result

in indentations in the raceways. Protrusions around the indentation exceed the height of the oil film,

resulting in deformation of surface asperities. Surface initiated fatigue caused by indentation arising

from plastic deformation is shown in A.2.6.2.
[1]

NOTE ISO 281 includes surface related calculation parameters that are known to have an influence on the

bearing life such as material, lubrication, environment, contamination particles and bearing load.

Figure 5 — Asperity microcracks and microspalls on a raceway
Figure 6 — Surface initiated microspalls on a raceway
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Figure 7 — Microspalled areas on a raceway
5.2 Wear
5.2.1 General description of wear

Wear is the progressive removal of material from the surface, resulting from the interaction of two

sliding or rolling/sliding contacting surfaces during service.
5.2.2 Abrasive wear

Abrasive wear (particle wear, three-body wear) is the removal of material due to sliding in presence

of hard particles. It is the result of a hard surface or particle removing material from another surface

through a cutting or ploughing action when sliding across it. The surfaces become dull to a degree, which

varies according to the coarseness and nature of the abrasive particles (see Figure 8). These particles

gradually increase in number as material is worn away from the running surfaces and, possibly, the

cage (see Figure 9). Finally, the wear becomes an accelerating process that results in a failed bearing.

Although the surfaces normally become dull to a certain extent, when the abrasive particles are very

fine, a polishing effect might occur, resulting in very shiny surfaces (see Figure 10).

NOTE The “running-in” of a rolling bearing is a natural short process after which the running behaviour,

e.g. noise or operating temperature, stabilizes or even improves. As a consequence, the running path or running

track becomes visible; however this is not indicating that the bearing is damaged.

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Figure 8 — Abrasive wear on the inner ring of a spherical roller bearing
Figure 9 — Advanced abrasive wear on the cage pockets of a solid metal cage

Figure 10 — Abrasive wear on the raceway of the large rib surface of the inner ring and on the

large end face of rollers in a tapered roller bearing
5.2.3 Adhesive wear

Adhesive wear is characterized by a transfer of material from one surface to another with frictional heat

and, sometimes, tempering or rehardening of the surface. This produces localized stress concentrations

with the potential for cracking or spalling of the contact areas.

Smearing (skidding, galling, scoring, frosting) occurs because of inadequate lubrication conditions

when sliding occurs and localized temperature rises from friction cause adhesion of the contacting

surfaces, resulting in material transfer. This typically happens between rolling elements and raceways

if the rolling elements are too lightly loaded and subjected to severe acceleration on their re-entry

into the load zone (see Figures 11 and 12). In severe cases of smearing, seizing may result. Smearing is

usually a sudden occurrence as opposed to an accumulated wear process.
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Smearing can also occur on the rib faces and on the ends of the rollers due to inadequate lubrication (see

Figure 13). In full complement (cageless) bearings, smearing can also occur in the contacts between

rolling elements, depending on lubrication and rotation conditions.

If a bearing ring moves (creeps) relative to its seat because of inadequate retention on the shaft or in

the housing, then smearing (also called scuffing) can occur in the bearing bore, the outside diameter

or on the shaft or in the housing seat. Because of the minute difference in the diameters of the two

components, they will have a minute difference in their circumferences and, consequently, when

brought into contact at successive points by the radial load rotating with respect to the ring, will rotate

at minutely different speeds. This rolling motion of the ring against its seating with a minute difference

in the rotational speeds is termed “creep”.

When creep occurs, the asperities in the ring/seat contact region are over-rolled, which can cause the

surface of the ring to take on a shiny appearance. The over-rolling during creeping is often, but not

always, accompanied by sliding in the ring/seat contact, and then other damage will also be visible, e.g.

score marks, fretting corrosion and wear. Under certain loading conditions and when the ring/seating

interference fit is insufficiently tight, fretting corrosion will predominate (see A.2.4.2.1 and A.2.4.2.2).

Furthermore, with a loose radial fit, creep can also occur between the face of a ring and its axial

abutment. In severe cases, this can lead to transverse thermal cracks and finally cause cracking of the

ring (see 5.6.4).
Figure 11 — Smearing on the outer ring raceway of a cylindrical roller bearing
Figure 12 — Smearing on the outer ring raceways of a spherical roller bearing
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Figure 13 — Smearing on the side face of rollers of a cylindrical roller bearing
5.3 Corrosion
5.3.1 General description of corrosion
Corrosion is the result of a chemical reaction on metal surfaces.
5.3.2 Moisture corrosion

When bearing components are in contact with moisture or aggressive media (e.g. water or acids),

oxidation or corrosion (rust) of surfaces takes place (see Figure 14). Subsequently, the formation of

corrosion pits occurs and finally spalling of the surface occurs (see Figure 15).

A specific form of moisture corrosion can be observed in the contact areas between rolling elements

and bearing rings where the water content in the lubricant or the degraded lubricant reacts with the

surfaces of the adjacent bearing elements. During static periods, the advanced stage will result in dark

discolouration of the contact areas at intervals corresponding to the ball/roller pitch (see Figure 16);

eventually producing corrosion pits.

Figure 14 — Moisture corrosion on the cage and rollers of a needle roller thrust bearing

Figure 15 — Moisture corrosion on the outer ring raceway of a cylindrical roller bearing

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Figure 16 — Contact corrosion at roller pitch on the inner ring raceway of a tapered roller bearing

5.3.3 Frictional corrosion
5.3.3.1 General description of frictional corrosion

Frictional corrosion (tribo-corrosion, tribo-oxidation) is a chemical reaction activated by relative

micromovements between mating surfaces under certain friction and load conditions. These

micromovements lead to oxidation of the surfaces and released material becoming visible as powdery

rust and/or loss of material from one or both mating surfaces.
5.3.3.2 Fretting corrosion

Fretting corrosion occurs in fit interfaces between components that are transmitting loads under

oscillating contact surface micromovements. Surface asperities oxidize and are rubbed off and vice

versa; powdery rust develops (fretting rust, iron oxide). The bearing surface becomes discoloured

blackish red (see Figure 17). Typically, the damage develops when loads and/or vibrations overcome

the radial clamping given by the mounting fits. Excessively rough and/or wavy surface finish of bearing,

shaft and housing surfaces can also reduce the effective mounting fit and induce fretting corrosion (see

Figure 18).

NOTE 1 Some abrasive wear might occur as a resultant effect of the presence of the corrosion products (iron

oxide) and micromovements.
NOTE 2 In this document, fretting corrosion is classified under corrosio
...

NORME ISO
INTERNATIONALE 15243
Deuxième édition
2017-03
Roulements — Détérioration
et défaillance — Termes,
caractéristiques et causes
Rolling bearings — Damage and failures — Terms, characteristics
and causes
Numéro de référence
ISO 15243:2017(F)
ISO 2017
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ISO 15243:2017(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2017, Publié en Suisse

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ISO 15243:2017(F)
Sommaire Page

Avant-propos ..............................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Domaine d’application ................................................................................................................................................................................... 1

2 Références normatives ................................................................................................................................................................................... 1

3 Termes et définitions ....................................................................................................................................................................................... 2

4 Classification des modes de défaillance survenant dans les roulements .................................................2

5 Modes de défaillance ........................................................................................................................................................................................ 3

5.1 Fatigue de contact de roulement ............................................................................................................................................. 3

5.1.1 Description générale de la fatigue de contact de roulement ..................................................... 3

5.1.2 Fatigue initiée en sous-couche ............................................................................................................................. 4

5.1.3 Fatigue initiée en surface .......................................................................................................................................... 4

5.2 Usure ................................................................................................................................................................................................................ 6

5.2.1 Description générale de l’usure .......................................................................................................................... 6

5.2.2 Usure par abrasion ......................................................................................................................................................... 6

5.2.3 Usure par adhésion ........................................................................................................................................................ 7

5.3 Corrosion ..................................................................................................................................................................................................... 9

5.3.1 Description générale de la corrosion ............................................................................................................. 9

5.3.2 Corrosion due à l’humidité ...................................................................................................................................... 9

5.3.3 Corrosion par frottement ......................................................................................................................................10

5.4 Électroérosion ......................................................................................................................................................................................12

5.4.1 Description générale de l’électroérosion .................................................................................................12

5.4.2 Érosion due à une surtension ............................................................................................................................12

5.4.3 Érosion due à une fuite de courant ...............................................................................................................13

5.5 Déformation plastique ...................................................................................................................................................................14

5.5.1 Description générale de la déformation plastique ..........................................................................14

5.5.2 Déformation due à une surcharge .................................................................................................................15

5.5.3 Indentations par des particules .......................................................................................................................16

5.6 Fissuration et rupture ....................................................................................................................................................................18

5.6.1 Description générale de la fissuration et de la rupture ...............................................................18

5.6.2 Rupture forcée ................................................................................................................................................................18

5.6.3 Rupture par fatigue ........................................................................................................................................... ..........18

5.6.4 Fissuration thermique .............................................................................................................................................19

Annexe A (informative) Analyse des défaillances — Illustration des détériorations —

Autres examens — Explication des termes utilisés .......................................................................................................21

Bibliographie ...........................................................................................................................................................................................................................55

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ISO 15243:2017(F)
Avant-propos

L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes

nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est

en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude

a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,

gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.

L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui

concerne la normalisation électrotechnique.

Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont

décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents

critères d’approbation requis pour les différents types de documents ISO. Le présent document a été

rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www

.iso .org/ directives).

L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de

droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable

de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant

les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de

l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de

brevets reçues par l’ISO (voir www .iso .org/ brevets).

Les appellations commerciales éventuellement mentionnées dans le présent document sont données

pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un

engagement.

Pour une explication de la nature volontaire des normes, la signification des termes et expressions

spécifiques de l’ISO liés à l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion

de l’ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles

techniques au commerce (OTC), voir le lien suivant: w w w . i s o .org/ iso/ fr/ avant -propos .html.

Le présent document a été élaboré par le comité technique ISO/TC 4, Roulements.

Cette deuxième édition annule et remplace la première édition (ISO 15243:2004), qui a fait l’objet d’une

révision technique.
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Introduction

Dans la pratique, la détérioration et/ou la défaillance d’un roulement peuvent souvent être le résultat

de plusieurs mécanismes se produisant simultanément. La défaillance peut être la conséquence d’un

transport, d’une manipulation ou d’un montage incorrects, d’une maintenance inadéquate ou d’un

défaut de fabrication du roulement ou de ses éléments adjacents. Dans certains cas, la défaillance est

due à un compromis fait au niveau de la conception pour des raisons d’intérêts économiques, voire à des

conditions de fonctionnement et environnementales imprévues. La combinaison complexe de plusieurs

facteurs de conception, de fabrication, de montage, de fonctionnement et de maintenance est souvent à

l’origine de difficultés au niveau de la détermination de la cause racine de la défaillance.

NOTE Il faut être conscient que des roulements de contrefaçon sont mis sur le marché. Ils peuvent ressembler

à des roulements originaux mais leur utilisation entraine souvent des défaillance et fracture prématurées.

En cas de détérioration importante ou de défaillance soudaine et totale du roulement, l’absence

d’indication évidente est probable, ce qui rend impossible l’identification de la cause racine de la

défaillance. De ce fait, il est important de mettre à l’arrêt l’équipement à temps pour permettre une

analyse appropriée des détériorations du roulement (voir Figure 1). Dans tous les cas, la connaissance

des conditions réelles de fonctionnement de l’ensemble et l’historique des travaux de maintenance se

révèlent de la plus haute importance.

NOTE L’écaillage a commencé juste derrière l’indentation dans le chemin de roulement [a)]. Il s’est

ensuite aggravé au fil du temps [b) et c)]. S’il n’est pas arrêté à temps, la preuve de la cause racine

disparaît [d)].
Figure 1 — Évolution de la détérioration du roulement

La classification des défaillances des roulements établie dans le présent document est principalement

fondée sur les caractéristiques visibles sur les surfaces de contact de roulement et sur d’autres surfaces

fonctionnelles. Chaque caractéristique est à prendre en compte pour déterminer de manière fiable la

cause racine de la défaillance du roulement. Dans la mesure où plusieurs mécanismes de défaillance

peuvent avoir des effets similaires sur lesdites surfaces, la description de l’aspect ne suffit généralement

pas, à elle seule, pour déterminer la cause de la défaillance. Dans certains/ces cas, il est nécessaire de

prendre les conditions de fonctionnement en considération. Dans certains cas, la détérioration analysée

est trop avancée et peut provenir de différentes causes primaires. Il est alors intéressant de rechercher

la présence simultanée d’indications pour déterminer la cause primaire de la défaillance.

Le présent document porte sur les roulements dotés de bagues en acier et d’éléments roulants. La

détérioration des bagues des roulements avec éléments roulants en céramique suit des modes de

défaillance similaires.
[1]

Dans le présent document, la durée de vie des roulements est comme décrit dans l’ISO 281 , qui prévoit

des formules pour calculer la durée de vie des roulements en prenant en compte un certain nombre de

facteurs, tels que la capacité de charge du roulement, le type de roulement, le matériau de fabrication, la

limite de fatigue du roulement, les conditions de lubrification et le degré de contamination.

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NORME INTERNATIONALE ISO 15243:2017(F)
Roulements — Détérioration et défaillance — Termes,
caractéristiques et causes
1 Domaine d’application

Le présent document classe les différents modes de défaillance survenant en cours de fonctionnement

pour les roulements en aciers standards. Elle définit et décrit, pour chaque mode de défaillance,

les caractéristiques, l’aspect et les possibles causes racines de la défaillance. Elle contribuera à

l’identification des modes de défaillance en s’appuyant sur l’aspect.
Les termes suivants sont expliqués pour les besoins du présent document:

— défaillance d’un roulement: résultat d’une détérioration qui empêche le roulement de satisfaire à

ses performances initialement prévues ou marque la fin de sa durée de vie;
— en service: état du roulement tel qu’il sort de l’usine du fabricant;

— caractéristiques visibles: caractéristiques qu’il est possible d’observer directement ou avec une loupe

ou un microscope optique, ainsi que celles observées sur des images, mais en utilisant uniquement

des méthodes non destructives.

L’analyse se limite aux formes caractéristiques du changement d’aspect et aux défaillances ayant un

aspect bien défini et pouvant être imputables à des causes particulières avec un degré de certitude

élevé. Les caractéristiques d’intérêt particulier relatives à l’explication des changements et des

défaillances sont décrites. Les formes diverses sont illustrées par des photographies et les causes les

plus fréquentes sont indiquées.

Si la cause racine ne peut pas être évaluée de manière fiable par l’examen et la description des

caractéristiques visuelles confrontés aux informations fournies dans le présent document, des examens

complémentaires sont à envisager. Ces méthodes sont résumées au A.3 et peuvent impliquer, par

exemple, l’utilisation de méthodes invasives pouvant inclure le prélèvement de coupes transversales,

des analyses métallurgiques structurelles au moyen de microscopes visuels ou électroniques et des

analyses chimiques et spectrographiques. Ces méthodes spécialisées ne sont pas incluses dans le

domaine d’application du présent document.

Les termes des modes de défaillance exprimés dans les titres des paragraphes sont recommandés pour

un usage général. Le cas échéant, les expressions alternatives ou synonymes utilisés pour décrire les

sous-modes sont indiqués et expliqués en A.4.

Des exemples de défaillances des roulements, accompagnés d’une description des causes de la

défaillance et des mesures correctives proposées, sont donnés en A.2.
2 Références normatives

Les documents suivants cités dans le texte constituent, pour tout ou partie de leur contenu, des

exigences du présent document. Pour les références datées, seule l’édition citée s’applique. Pour les

références non datées, la dernière édition du document de référence s’applique (y compris les éventuels

amendements).
ISO 5593, Roulements — Vocabulaire
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3 Termes et définitions

Pour les besoins du présent document, les termes et définitions donnés dans l’ISO 5593 ainsi que les

suivants s’appliquent.

NOTE Des explications de termes de détérioration et défaillance sont données en A.4.

L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en

normalisation, consultables aux adresses suivantes:
— IEC Electropedia: disponible à l’adresse http:// www .electropedia .org/

— ISO Online browsing platftorm: disponible à l’adresse http:// www .iso .org/ obp

3.1
caractéristiques
aspect visuel résultant de la performance d’usage
[3]

Note 1 à l’article: Les défauts de surface et les types de changements géométriques sont définis dans l’ISO 8785

[2]
et, en partie, dans l’ISO 6601 (portant sur l’usure par abrasion).
3.2
détérioration

toute détérioration visible des surfaces ou structures de fonctionnement du roulement

3.3
séquences d’événements

séquence d’événements aboutissant à la défaillance (3.4) du roulement, en commençant par la

détérioration (3.2) initiale du roulement

Note 1 à l’article: À un stade précoce, cette détérioration peut causer une perte fonctionnelle ou une défaillance.

Cependant, dans de nombreux cas, la détérioration initiale n’aboutit pas à une défaillance et le roulement continue

de fonctionner. La poursuite du fonctionnement provoque généralement une détérioration secondaire qui aboutit

finalement à une défaillance. La détérioration secondaire peut introduire des modes de défaillance concurrents,

ce qui peut compliquer l’analyse de la cause racine.
3.4
défaillance

toute situation dans laquelle le roulement n’est plus en mesure d’assurer son fonctionnement prévu

Note 1 à l’article: Cela comprendra la dégradation de propriétés rotationnelles essentielles et l’avertissement

d’une défaillance plus étendue ou totale imminente, sans pour autant que le stade soit suffisamment avancé pour

empêcher la rotation ou le support des éléments de machine concernés.

Note 2 à l’article: L’étendue de la détérioration (3.2) requise pour enregistrer une déclaration de défaillance

opérationnelle dépendra de l’application. Les applications nécessitant une rotation précise et sans à-coups

ne toléreront qu’une perte très minime de propriétés. Les applications non sensibles à des amplifications de

vibrations ou de bruits ou à une précision rotationnelle réduite peuvent être capables de continuer à assurer

leurs performances pendant une période restreinte.
3.5
mode de défaillance
manière selon laquelle la défaillance d’un roulement se déclare
4 Classification des modes de défaillance survenant dans les roulements

Il conviendrait de préférence que les détériorations et défaillances des roulements soient classées

selon la cause racine. Cependant, il n’est pas souvent facile de distinguer les causes des caractéristiques

(symptômes); en d’autres termes, de faire la distinction entre mécanismes et modes de défaillance. Cela

est confirmé par le grand nombre d’articles et d’ouvrages traitant de ce sujet (voir Bibliographie). Par

conséquent, dans le présent document, les modes de défaillance sont classés en six groupes principaux

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et en différents sous-groupes (voir Figure 2), en fonction de leur aspect caractéristique distinctif en

service.
Figure 2 — Classification des modes de défaillance
5 Modes de défaillance
5.1 Fatigue de contact de roulement
5.1.1 Description générale de la fatigue de contact de roulement

La fatigue de contact de roulement est provoquée par les contraintes répétées développées au niveau

du contact entre les éléments roulants et les chemins de roulement. La fatigue se manifeste visiblement

sous la forme d’une modification de la structure (microstructure) et d’un écaillage à la surface du

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matériau (macrostructure) qui, dans la plupart des cas, pourraient entraîner une modification de la

microstructure.
NOTE Ecaillage et écaillage avancé sont synonymes (voir A.4).
5.1.2 Fatigue initiée en sous-couche

Sous l’influence d’une charge cyclique exercée sur les contacts de roulement, décrite par la théorie de

Hertz, des contraintes et des changements structurels du matériau se produisent et des microfissures se

forment à des emplacements et à des profondeurs dépendant de la charge appliquée, de la température

de fonctionnement, du matériau et de sa propreté, ainsi que de la microstructure. La formation de

microfissures est souvent provoquée par des inclusions dans l’acier du roulement.

Les changements peuvent apparaître à l’examen métallurgique (voir A.3). Ces fissures se propagent et

provoquent un écaillage une fois arrivées en surface (voir Figures 3 et 4).
Figure 3 — Écaillage initial en sous-couche dans un roulement à billes à gorges
profondes — Bague intérieure tournante

Figure 4 — Écaillage avancé en sous-couche dans un roulement à rouleaux coniques — Bague

intérieure fixe
5.1.3 Fatigue initiée en surface

La fatigue initiée en surface est généralement provoquée par une dégradation de surface appelé aussi

surface distress (aplatissement des micro-rugosités).

La surface distress est la détérioration initiée aux surfaces de contact du roulement due aux

déformations plastiques des aspérités de surface (lissage, polissage, glaçage). Le contact entre les

aspérités des éléments roulants et du chemin de roulement est le plus souvent le résultat de conditions de

lubrification inappropriées (épaisseur du film de lubrifiant insuffisante). Ce contact peut être provoqué

par une circulation/un apport de lubrification insuffisant(e), un lubrifiant impropre à l’application, des

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températures de fonctionnement au-dessus des niveaux attendus ou un état de surface rugueux. Le

contact et la déformation plastique des aspérités de surface peuvent entrainer:
— des microfissures (voir Figure 5),
— des micro-écaillages (voir Figure 6), et
— des zones micro-écaillées (taches grises) (voir Figure 7).

En cas de film lubrifiant de faible épaisseur, le glissement peut accélérer considérablement la

détérioration de la surface.

Dans les cas pour lesquels l’épaisseur du film est suffisante pour des conditions de fonctionnement

normal, une fatigue initiée en surface peut toujours apparaitre. Cela peut se produire quand des

particules sont introduites dans la zone de contact (voir 5.5.3), des charges extrêmes déforment

plastiquement la surface ou des empreintes de manipulation (coup d’angle) sont présentes. Ces

trois conditions entrainent des indentations dans les chemins de roulements. Des bourrelets autour

des indentations dépassent la hauteur du film d’huile, entrainant des déformations des aspérités de

surfaces. La fatigue initiée en surface, causée par l’indentation due à la déformation plastique, est

illustrée en A.2.6.2.
[1]

NOTE L’ISO 281 comprend des paramètres de calcul relatifs à la surface et connus pour avoir une influence

sur la durée de vie du roulement, tels que le matériau, la lubrification, l’environnement, les particules de pollution

et la charge au niveau du roulement.
Figure 5 — Microfissures et micro-écaillages sur un chemin de roulement
Figure 6 — Micro-écaillages initiés en surface sur un chemin de roulement
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Figure 7 — Zones micro-écaillées sur un chemin de roulement
5.2 Usure
5.2.1 Description générale de l’usure

L’usure est l’enlèvement progressif de matière en surface résultant de l’interaction entre deux surfaces

en contact de glissement ou de roulement/glissement en cours de fonctionnement.
5.2.2 Usure par abrasion

L’usure par abrasion (usure sous l’action de particules, usure entre trois corps) est l’enlèvement de

matière dû au glissement en présence de particules solides. Elle est le résultat d’une surface ou particule

solide qui enlève de la matière d’une autre surface par une action de coupe ou de labourage en glissant

sur celle-ci. Les surfaces deviennent mates à un degré qui varie en fonction de la taille et de la nature

des particules abrasives (voir Figure 8). Le nombre de particules augmente progressivement avec

l’usure du matériau des surfaces en contact et potentiellement de la cage (voir Figure 9). Finalement, le

processus d’usure s’accélère jusqu’à détérioration du roulement.

Bien que les surfaces deviennent normalement mates dans une certaine mesure, un effet de polissage

peut se produire lorsque les particules abrasives sont très fines, résultant en des surfaces très brillantes

(voir Figure 10).

NOTE Le «rodage» d’un roulement est un processus naturel court à l’issue duquel le comportement en

rotation, par exemple le bruit ou la température de fonctionnement, se stabilise, voire s’améliore. La trace de

fonctionnement devient ainsi visible; cependant, cela n’indique pas que le roulement est détérioré.

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Figure 8 — Usure par abrasion sur la bague intérieure d’un roulement à rotule sur rouleaux

Figure 9 — Usure par abrasion avancée des alvéoles d’une cage métallique solide

Figure 10 — Usure par abrasion sur le chemin de roulement du collet de la bague intérieure et

sur la grande face des rouleaux d’un roulement à rouleaux coniques
5.2.3 Usure par adhésion

L’usure par adhésion est caractérisée par un transfert de matière d’une surface à une autre avec

échauffement par frottement et, parfois, recuit ou retrempe de la surface. Cela génère des concentrations

de contraintes localisées avec possibilité de fissuration ou d’écaillage des zones de contact.

Le smearing (éraillure) (patinage, usure par frottement, strie, dépolissage) apparaît en cas de conditions

inappropriées de lubrification, lorsqu’un glissement se produit et que les augmentations locales de

température dues aux frottements provoquent une adhésion des surfaces en contact, résultant en

un transfert de matière. Cela se produit généralement entre les éléments roulants et les chemins de

roulement si les éléments roulants sont trop légèrement chargés et subissent une forte accélération

lorsqu’ils entrent de nouveau dans la zone de charge (voir Figures 11 et 12). Dans des cas sévères de

smearing (éraillure), un grippage avancé peut en résulter. L’apparition de smearing (éraillure) est

généralement soudaine, contrairement à un processus d’usure accumulée.
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Le smearing (éraillures) peut également survenir sur les collets et sur les extrémités des rouleaux suite

à une lubrification inappropriée (voir Figure 13). Sur les roulements à éléments roulants jointifs (sans

cage), le smearing (éraillures) peut aussi survenir au niveau des points de contact entre les éléments

roulants en fonction des conditions de lubrification et de rotation.

Si une bague de roulement bouge (roule) sur sa portée, en raison d’un maintien inapproprié de l’arbre

dans le logement, le smearing (éraillure) (également appelé éraflure) peut alors se produire dans

l’alésage du roulement, sur le diamètre extérieur, sur l’arbre ou dans la portée du logement. Une

différence minime de diamètre entre deux composants entraîne un écart infime des circonférences

respectives, et donc un léger décalage des vitesses de rotation lorsqu’ils entrent en contact à des points

successifs sous l’effet de la charge radiale en rotation par rapport à la bague. Ce mouvement de rotation

de la bague par rapport à sa portée, avec une infime différence des vitesses de rotation, est désigné par

«reptation».

En cas de reptation, les aspérités situées au niveau de la zone de contact bague/portée sont laminées

par les passages répétés des éléments roulants, ce qui peut donner à la bague un aspect brillant en

surface. Ce «laminage» au cours du roulage s’accompagne souvent, mais pas systématiquement, d’un

glissement au point de contact bague/portée et fait ensuite apparaître d’autres détériorations, par

exemple stries, corrosion par frottement et usure. Sous certaines conditions de charge et lorsque

l’ajustement bague/portée n’est pas suffisamment serré, cela donne libre cours à la corrosion de contact

(voir A.2.4.2.1 et A.2.4.2.2).

Avec un ajustement radial libre, la reptation peut également survenir entre la face d’une bague et son

appui axial. Dans les cas sévères, cela peut créer des fissures thermiques transversales et provoquer

finalement la fissuration de la bague (voir 5.6.4).

Figure 11 — Smearing (éraillures) sur le chemin de roulement de la bague extérieure d’un

roulement à rouleaux cylindriques

Figure 12 — Smearing (éraillures) sur les chemins de roulement de la bague extérieure d’un

roulement à rotule sur rouleaux
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Figure 13 — Smearing (éraillures) sur la face latérale des rouleaux d’un roulement à rouleaux

cylindriques
5.3 Corrosion
5.3.1 Description générale de la corrosi
...

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