EN 13261:2024
(Main)Railway applications - Wheelsets and bogies - Axles - Product requirements
Railway applications - Wheelsets and bogies - Axles - Product requirements
This document specifies the characteristics of axles for all heavy rail track gauges.
This document applies to heavy rail vehicles and applies, in principle, to other vehicles such as urban rail vehicles.
It specifies characteristics of forged or rolled solid and hollow axles, made from vacuum-degassed steel grade EA1N, EA1T and EA4T. For hollow axles, this document applies only to those that are manufactured by machining of a hole in a forged or rolled solid axle.
The requirements specified in this document are applicable for cylindrical seats. Most of the requirements are also applicable for axles with conical seats. Specific requirements for conical seats (e.g. geometrical dimensions of the seats...) are defined in the technical specification.
Some characteristics are given as a function of a category 1 or of a category 2.
This document is applicable to axles that are designed in accordance with the requirements of EN 13103-1:2017+A1:2022.
This document also permits variations of the material characteristics linked to alternative manufacturing processes (e.g. cold rolling, shot blasting, thermal spraying, steel cleanliness, reduction ratio, improved material properties from melting and heat treatment process, etc.).
Bahnanwendungen - Radsätze und Drehgestelle - Radsatzwellen - Produktanforderungen
Dieses Dokument legt die Eigenschaften von Radsatzwellen für alle Vollbahnspurweiten fest.
Dieses Dokument ist für Vollbahnfahrzeuge und grundsätzlich für andere Fahrzeuge wie städtische Schienenbahnen anwendbar.
Es legt Eigenschaften für geschmiedete oder gewalzte massive und längsgebohrte Radsatzwellen aus den vakuumentgasten Stahlsorten EA1N , EA1T1 und EA4T1 fest. Für längsgebohrte Radsatzwellen gilt diese Norm nur, wenn diese durch mechanische Bearbeitung der Bohrung in einer geschmiedeten oder gewalzten massiven Radsatzwelle hergestellt werden.
Die in dieser Norm festgelegten Anforderungen sind für zylindrische Radsitze anwendbar. Die meisten Anforderungen sind darüber hinaus für Radsatzwellen mit konischen Radsitzen anwendbar. Spezifische Anforderungen an konische Radsitze (z. B. geometrische Maße der Radsitze) werden in der technischen Spezifikation festgelegt.
Einige Eigenschaften sind in Abhängigkeit von Kategorie 1 oder Kategorie 2 angegeben.
Dieses Dokument ist für Radsatzwellen, die in Übereinstimmung mit den Anforderungen nach EN 13103 1:2017+A1:2022 entworfen wurden, anwendbar.
Dieses Dokument erlaubt außerdem Abweichungen der Materialeigenschaften in Verbindung mit alternativen Fertigungsprozessen (z. B. Festwalzen, Kugelstrahlen, thermisches Spritzen, Stahlreinheit, Schmiedeverformungsgrad, Verbesserung der Werkstoffeigenschaften durch das Schmelzverfahren und den Wärmebehandlungsprozess usw.).
Applications ferroviaires - Essieux montés et bogies - Essieux-axes - Prescriptions pour le produit
Le présent document spécifie les caractéristiques des essieux-axes pour tous les écartements de voie des véhicules ferroviaires lourds.
Le présent document s'applique aux véhicules ferroviaires lourds et s'applique, en principe, à d'autres véhicules tels que les véhicules ferroviaires urbains.
Il spécifie les caractéristiques des essieux-axes pleins et creux, forgés ou laminés, en acier dégazé sous vide, de nuance EA1N, EA1T et EA4T. Pour les essieux-axes creux, le présent document s'applique seulement à ceux qui sont fabriqués par usinage d'un trou dans un essieu-axe plein forgé ou laminé.
Les exigences spécifiées dans le présent document sont applicables aux portées de calage cylindriques. La plupart des exigences sont également applicables aux essieux-axes à portées de calage coniques. Des exigences spécifiques pour les portées coniques (par exemple, dimensions géométriques des portées de calage, etc.) sont définies dans la spécification technique.
Quelques caractéristiques sont données en fonction d'une catégorie 1 ou d'une catégorie 2.
Le présent document est applicable aux essieux-axes qui sont conçus conformément aux exigences de l'EN 13103-1:2017+A1:2022.
Le présent document admet également des variations des caractéristiques du matériau en relation avec des procédés alternatifs de fabrication (par exemple, galetage, grenaillage, dépôt de métal par projection thermique, propreté de l'acier, taux de corroyage, propriétés améliorées du matériau par un procédé de fusion et de traitement thermique, etc.).
Železniške naprave - Kolesne dvojice in podstavni vozički - Osi - Zahtevane lastnosti proizvoda
Ta dokument določa značilnosti osi za vse širine tirov v težkem železniškem omrežju.
Ta dokument se uporablja za težka železniška vozila in se načeloma uporablja tudi za druga vozila, kot so mestna tirna vozila.
Določa značilnosti kovanih ali valjanih trdnih in votlih osi, izdelanih iz vakuumsko razplinjenega jekla razredov EA1N1), EA1T1) in EA4T1). Pri votlih oseh se ta dokument uporablja samo za tiste, ki so izdelane z izoblikovanjem luknje v kovani ali valjani trdni osi.
Zahteve v tem dokumentu se uporabljajo za valjaste sedeže. Večina zahtev se uporablja tudi za osi s stožčastim sedežem. Posebne zahteve za stožčaste sedeže (npr. geometrijske mere sedežev itd.) so opredeljene v tehnični specifikaciji.
Nekatere značilnosti so podane kot funkcija kategorije 1 ali 2.
Ta dokument se uporablja za osi, ki so konstruirane v skladu z zahtevami standarda EN 13103-1:2017+A1:2022.
Ta dokument dovoljuje tudi spremembe značilnosti materiala, povezane z alternativnimi proizvodnimi postopki (npr. hladno valjanje, peskanje, vroče brizganje, čistost jekla, redukcijsko razmerje, izboljšane lastnosti materiala zaradi postopka taljenja in toplotne obdelave itd.).
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2025
Nadomešča:
SIST EN 13261:2020
Železniške naprave - Kolesne dvojice in podstavni vozički - Osi - Zahtevane
lastnosti proizvoda
Railway applications - Wheelsets and bogies - Axles - Product requirements
Bahnanwendungen - Radsätze und Drehgestelle - Radsatzwellen -
Produktanforderungen
Applications ferroviaires - Essieux montés et bogies - Essieux-axes - Prescription pour le
produit
Ta slovenski standard je istoveten z: EN 13261:2024
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 13261
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2024
EUROPÄISCHE NORM
ICS 45.040 Supersedes EN 13261:2020
English Version
Railway applications - Wheelsets and bogies - Axles -
Product requirements
Applications ferroviaires - Essieux montés et bogies - Bahnanwendungen - Radsätze und Drehgestelle -
Essieux-axes - Prescriptions pour le produit Radsatzwellen - Produktanforderungen
This European Standard was approved by CEN on 6 October 2024.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13261:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Product definition . 9
4.1 Chemical composition . 9
4.1.1 Values to be achieved . 9
4.1.2 Sampling methods . 9
4.1.3 Chemical analysis . 9
4.2 Mechanical characteristics .10
4.2.1 Characteristics from the tensile test .10
4.2.2 Impact test characteristics .11
4.2.3 Fatigue characteristics .14
4.3 Microstructure characteristics.16
4.3.1 Values to be achieved .16
4.3.2 Position of the test piece.16
4.3.3 Test method .16
4.4 Material cleanliness .17
4.4.1 Micrographic cleanliness .17
4.4.2 Internal integrity .18
4.5 Permeability to ultrasound .18
4.5.1 General .18
4.5.2 Level to be achieved .18
4.5.3 Test piece .18
4.5.4 Test method .19
4.6 Residual stresses .19
4.6.1 General .19
4.6.2 Values to be achieved .19
4.6.3 Test piece and position of measurement points .20
4.6.4 Measurement method .20
4.7 Surface characteristics .20
4.7.1 Surface finish .20
4.7.2 Surface integrity .23
4.8 Geometrical and dimensional tolerances.25
4.9 Protection against corrosion and against mechanical aggression .29
4.9.1 Final protection .29
4.9.2 Temporary protection .35
4.10 Marking .35
4.11 Material reduction ratio .36
5 Alternative manufacturing process .36
6 Product qualification .36
7 Conditions of supply .36
Annex A (informative) Material sampling from axle journal extension .37
A.1 General .37
A.2 Sampling method . 37
A.3 Values to be achieved . 37
Annex B (informative) Drawings of test pieces . 39
Annex C (normative) Standard sample block for measurement of permeability to ultrasound
................................................................................................................................................................... 42
C.1 Sample block . 42
C.2 Tolerances of the standard sample block . 44
C.3 Steel grade of the standard sample block . 44
Annex D (informative) Position of testing points for the permeability to ultrasound . 45
Annex E (informative) Residual stress measurement with strain gauges with saw cutting . 46
Annex F (informative) Method for blasting after machining . 47
F.1 Blasting principle . 47
F.2 Requirements . 47
F.3 Parameters . 48
F.4 Blasting qualification process . 48
Annex G (normative) Method to assess resistance to impact of the coating . 49
G.1 Principle . 49
G.2 Test piece . 49
G.3 Apparatus . 49
G.4 Procedure . 49
G.5 Expression of results . 49
Annex H (normative) Method to assess resistance to gritting of the coating . 50
H.1 Introduction . 50
H.2 Test piece . 50
H.3 Apparatus . 50
H.4 Procedure . 50
H.5 Expression of results . 50
Annex I (normative) Method to assess the resistance of the coating to specific corrosive
products . 51
I.1 Principle . 51
I.2 Test piece . 51
I.3 Apparatus . 51
I.4 Corrosive products . 51
I.5 Procedure . 51
I.6 Expression of results . 52
Annex J (informative) Method to assess the resistance of the coating to cyclic mechanical
stresses .53
J.1 Purpose .53
J.2 Principle .53
J.3 Test piece .53
J.4 Apparatus .53
J.5 Procedure.53
J.6 Expression of results .54
Annex K (normative) Product qualification .55
K.1 General .55
K.2 Requirements and procedures .55
K.3 Requirements .58
K.4 Qualification procedure .58
K.5 Qualification validity .60
K.6 Qualification file .60
K.7 Qualification of the longitudinal machining of bores in the axles .61
Annex L (normative) Conditions of supply of the product .62
L.1 General .62
L.2 Technical specification content .62
L.3 Delivery condition .63
L.4 Controls on each axle .63
L.5 Batch control .63
L.6 Quality plan .66
L.7 Allowable rectification .66
Annex M (normative) Measurement of the hydrogen content in the steel for axles at the
melting stage .68
M.1 General .68
M.2 Sampling .68
M.3 Analysis methods .68
M.4 Precautions.68
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive (EU) 2016/797 aimed to be covered .69
Bibliography .71
European foreword
This document (EN 13261:2024) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2025, and conflicting national standards shall be
withdrawn at the latest by May 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13261:2020.
The main changes compared with EN 13261:2020 are as follows:
— an improved definition of the product groups submitted to qualification;
— improved requirements to assess product qualification after changes made in the manufacturing
process;
— additional possibilities to carry out tests with axle journal extensions;
— an improved definition of the aim of the full-size fatigue test;
— an improved definition of the requirements regarding material microstructure;
— some additional information or requirements on the qualification and NDT tests of hollow-bore
axles;
— the replacement of the historical test to check the resistance of the paint to bending stress by more
pragmatic and cheaper tests;
— new requirements on the traceability of the qualification and of the batch control.
The informative annexes to this document provide additional guidance that is not mandatory but that
helps to understand or use the document.
The informative annexes may contain optional requirements. For example, a test method that is optional,
or presented as an example, may contain requirements, but it is not necessary to meet these requirements
to be in compliance with the document.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annex ZA, which is an integral part of this
document.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
1 Scope
This document specifies the characteristics of axles for all heavy rail track gauges.
This document applies to heavy rail vehicles and applies, in principle, to other vehicles such as urban rail
vehicles.
It specifies characteristics of forged or rolled solid and hollow axles, made from vacuum-degassed steel
1) 1) 1)
grade EA1N , EA1T and EA4T . For hollow axles, this document applies only to those that are
manufactured by machining of a hole in a forged or rolled solid axle.
The requirements specified in this document are applicable for cylindrical seats. Most of the
requirements are also applicable for axles with conical seats. Specific requirements for conical seats (e.g.
geometrical dimensions of the seats…) are defined in the technical specification.
Some characteristics are given as a function of a category 1 or of a category 2.
This document is applicable to axles that are designed in accordance with the requirements of
EN 13103-1:2017+A1:2022.
This document also permits variations of the material characteristics linked to alternative manufacturing
processes (e.g. cold rolling, shot blasting, thermal spraying, steel cleanliness, reduction ratio, improved
material properties from melting and heat treatment process, etc.).
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.
EN 13103-1:2017+A1:2022, Railway applications — Wheelsets and bogies — Part 1: Design method for
axles with external journals
EN ISO 148-1:2016, Metallic materials — Charpy pendulum impact test — Part 1: Test method (ISO 148-
1:2016)
EN ISO 643:2012, Steels — Micrographic determination of the apparent grain size (ISO 643:2012)
EN ISO 1519:2011, Paints and varnishes — Bend test (cylindrical mandrel) (ISO 1519:2011)
EN ISO 1520:2006, Paints and varnishes — Cupping test (ISO 1520:2006)
EN ISO 2409:2020, Paints and varnishes — Cross-cut test (ISO 2409:2020)
EN ISO 2808:2019, Paints and varnishes — Determination of film thickness (ISO 2808:2019)
EN ISO 4624:2023, Paints and varnishes — Pull-off test for adhesion (ISO 4624:2023)
EN ISO 6892-1:2019, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
(ISO 6892-1:2019)
1)
N for a normalized metallurgical condition
T for a quenched and tempered metallurgical condition
EN ISO 9227:2022, Corrosion tests in artificial atmospheres — Salt spray tests (ISO 9227:2022)
EN ISO 11997-1:2017, Paints and varnishes — Determination of resistance to cyclic corrosion conditions
— Part 1: Wet (salt fog)/dry/humid (ISO 11997-1:2017)
EN ISO 14284:2022, Steel and iron — Sampling and preparation of samples for the determination of
chemical composition (ISO 14284:2022)
EN ISO 16276-2:2007, Corrosion protection of steel structures by protective paint systems — Assessment
of, and acceptance criteria for, the adhesion/cohesion (fracture strength) of a coating — Part 2: Cross-cut
testing and X-cut testing (ISO 16276-2:2007)
EN ISO 22081:2021, Geometrical product specifications (GPS) — Geometrical tolerancing — General
geometrical specifications and general size specifications (ISO 22081:2021)
ISO 4967:2013, Steel — Determination of content of non-metallic inclusions — Micrographic method using
standard diagrams
ISO 5948:2018, Railway rolling stock material — Ultrasonic acceptance testing
ISO 6933:1986, Railway rolling stock material — Magnetic particle acceptance testing
2)
ISO/TR 9769:2018, Steel and iron — Review of available methods of analysis
CEN/TS 13103-2:2020, Railway applications — Wheelsets and bogies — Part 2: Design method for axles
with internal journals
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at https://www.electropedia.org/
3.1
technical specification
document specifying parameter and/or product requirements as an addition to the requirements of this
document
3.2
batch
group of axles supposed to have the same characteristics
Note 1 to entry: A batch consists of axles of the same design forged or rolled with raw material of a single heat in
an identical hot forming process and heat treated at the same time in an identical procedure. If the raw material is
produced in several heats with the expected chemical composition, the axles made thereof can be combined to a
batch. In this case, it needs to be proven within the frame of the product qualification that the axles made of the
various heats comply with the requirements of the product qualification.
2)
See also CEN/TR 10261:2023.
3.3
axle category
classification of the component, based on operational aspects, which determines the list of requirements
to be applied
Note 1 to entry: Category 1 is generally selected when the operating train speed is greater than 200 km/h.
Note 2 to entry: Category 2 is generally selected when the operating speed is 200 km/h or less.
Note 3 to entry: These categories can also be defined according to the technical specification.
4 Product definition
4.1 Chemical composition
4.1.1 Values to be achieved
The values for percentage contents of the various elements shall be in accordance with Table 1.
Table 1 — Limit values by product analysis
a a, b
C Si Mn Cr Cu Mo Ni V
P S
Grade
% % % % % % % %
% %
a,
≤ 0,40 ≤ 0,50 ≤ 1,20 ≤ 0,020 ≤ 0,30 ≤ 0,30 ≤ 0,08 ≤ 0,30 ≤ 0,06
≤ 0,015
EA1N
b
a,
≤ 0,40 ≤ 0,50 ≤ 1,20 ≤ 0,020 ≤ 0,30 ≤ 0,30 ≤ 0,08 ≤ 0,30 ≤ 0,06
≤ 0,015
EA1T
b
b
≥ 0,22 ≥ 0,15 ≥ 0,50 ≤ 0,020 ≥ 0,90 ≤ 0,30 ≥ 0,15 ≤ 0,30 ≤ 0,06
≤ 0,015
EA4T
≤ 0,29 ≤ 0,40 ≤ 0,80 ≤ 1,20 ≤ 0,30
a
A maximum content of 0,025 % may be defined in the technical specification.
b
A minimum sulphur content may be defined in the technical specification according to the steelmaking process, in order
to safeguard against hydrogen embrittlement.
4.1.2 Sampling methods
The test sample shall be taken at mid-radius of solid axles or at mid-distance between external and
internal surfaces of hollow axles.
The chemical composition can alternatively be determined by ladle analysis. In this case, the limit values
shall be defined in the technical specification.
For forged axles, when defined in the technical specification, the sample may be taken from an axle
journal extension as stated in Annex A.
4.1.3 Chemical analysis
The chemical composition analysis shall be performed according to the methods and definitions specified
in ISO/TR 9769:2018 unless another standard is defined in the technical specification.
NOTE ASTM E415-21 and ASTM E1019-18 can be applied.
4.2 Mechanical characteristics
4.2.1 Characteristics from the tensile test
4.2.1.1 Values to be achieved
The values to be achieved at mid-radius of solid axles or at mid-distance between external and internal
surfaces of hollow axles are given in Table 2.
The values to be achieved near the external surface shall be greater than or equal to 0,95 times the values
measured at mid-radius of solid axles or at the mid-distance between external and internal surfaces of
hollow axles.
The values to be achieved in the centre of solid axles or near the internal surface of hollow axles shall be
greater than or equal to 0,8 times the values measured at mid-radius or at mid-distance between external
and internal surfaces.
Table 2 — Values to be achieved at mid-radius of solid axles or at mid-distance between external
and internal surfaces of hollow axles
a
Grade R A
R
m 5
eH
MPa %
MPa
EA1N ≥ 320 550 - 650 ≥ 22
EA1T ≥ 350 550 - 700 ≥ 24
EA4T ≥ 420 650 - 800 ≥ 18
a
If no distinctive yield strength is present, the proof stress R shall be determined.
p0,2
4.2.1.2 Position of the test pieces
The test pieces shall be taken at three levels from the largest diameter section of the axle:
— as near as possible to the external surface for all the axles,
— at mid-radius and in the centre of solid axles,
— at mid-distance between external and internal surfaces, and near the internal surface of hollow axles,
as shown in Figure 1 a) and b).
For forged axles, when defined in the technical specification, the sample may be taken from an axle
journal extension as stated in Annex A.
Dimensions in millimetres
a) — Solid axle
b) — Hollow axle
Figure 1 — Position of test pieces
4.2.1.3 Test method
The test shall be carried out in accordance with EN ISO 6892-1:2019. The test piece diameter shall be at
least 10 mm in the machined-down portion. The gauge length shall be five times the diameter.
4.2.2 Impact test characteristics
4.2.2.1 Values to be achieved
Impact test characteristics shall be determined in the longitudinal and the transverse directions.
Values to be achieved at mid-radius of solid axles, or at mid-distance between external and internal
surfaces of hollow axles, are given in Table 3.
Near the surface, the average value calculated from 3 specimens shall be greater than or equal to
0,95 times the average values measured at mid-radius or at mid-distance between external and internal
surfaces of hollow axles.
In the centre of solid axles or near the internal surface of hollow axles, the average value calculated from
3 specimens shall be greater than 0,8 times the average values measured at mid-radius or at mid-distance
between external and internal surfaces.
For forged axles, when defined in the technical specification, the sample may be taken from an axle
journal extension as stated in Annex A.
No individual value shall be less than the minimum values defined in Table 3.
Table 3 — Values to be achieved at mid-radius of solid axles or at mid-distance between external
and internal surfaces of hollow axles
Average KU Minimum KU Average KU Minimum KU
longitudinal longitudinal transverse transverse
Grade
J J J J
EA1N ≥ 30 ≥ 21 ≥ 20 ≥ 14
EA1T ≥ 40 ≥ 28 ≥ 25 ≥ 18
EA4T ≥ 40 ≥ 28 ≥ 25 ≥ 18
4.2.2.2 Position of test pieces
The test pieces shall be taken from three levels in the largest axle section:
— as near as possible to the external surface for all the axles;
— at mid-radius and in the centre of solid axles;
— at mid-distance between external and internal surfaces, and near the internal surface of hollow axles;
as shown in Figure 2a) and 2b).
For forged axles, when defined in the technical specification, a test piece may be taken from axle journal
extensions as stated in Annex A.
4.2.2.3 Test method
The Charpy pendulum impact test shall be carried out in accordance with EN ISO 148-1:2016.
Dimensions in millimetres
a) Solid axle
b) Hollow axle
Key
1 longitudinal test piece
2 transverse test piece
Figure 2 — Position of test pieces
4.2.3 Fatigue characteristics
4.2.3.1 General
4.2.3.1.1 Principles
Verification of the fatigue characteristics is essential in order to have a correctly dimensioned axle. The
satisfactory performance of an axle in service depends upon these characteristics. The values defined in
this subclause shall be used for the calculation of the maximum permissible stresses that are referred to
in the design rules in EN 13103-1:2017+A1:2022 and CEN/TS 13103-2:2020.
It is necessary to determine the fatigue limits in the following two areas, in order to predict the behaviour
of the axle under in-service stresses:
— for the material, tests are performed on small-scale test pieces, for which the shapes do not depend
upon the product geometry;
— for the product, tests are performed on full-scale test pieces, for which the dimensions and
manufacturing process are similar to the final product and its associated permissible manufacturing
defects.
4.2.3.1.2 Fatigue limits on small-scale test pieces
The fatigue limits defined for reduced test pieces are used to verify that the notch effect of the material
used for the manufacture of the axle is in accordance with the safety coefficient “S” defined in design
standard EN 13103-1:2017+A1:2022 and CEN/TS 13103-2:2020. They are determined from:
— unnotched surface test pieces (fatigue limit R );
fL
— notched test pieces (fatigue limit R ).
fE
4.2.3.1.3 Fatigue limits on full-scale test pieces
The limits determined on full-scale test pieces are intended to verify that the fatigue characteristics are
in accordance with those that are used to calculate the maximum permissible stresses referred to in
design standards EN 13103-1:2017+A1:2022 and CEN/TS 13103-2:2020.
These fatigue limits apply to different axle areas. Only the fatigue limits applying to the axle body are
taken into account in this standard.
NOTE The limits applying to the axle seats depend partly on the assembly and are referred to in
EN 13260:2020.
It is necessary to define two fatigue limits:
— on the body surface, limit F ;
— on the bore surface in the case of a hollow axle, limit F . The limit F has not to be verified for the
2 2
steel presented in the scope of this standard.
4.2.3.2 Values to be achieved
The values to be achieved are given in Table 4.
Table 4 — Fatigue limit values
a
q = R / R
fL fE
F F R R
1 2 fL fE
Grade
(informative
MPa MPa MPa MPa
values)
EA1N ≥ 200 ≥ 80 ≥ 250 ≥ 170 ≤1,47
EA1T ≥ 200 ≥ 80 ≥ 250 ≥ 170 ≤1,47
EA4T ≥ 240 ≥ 96 ≥ 350 ≥ 215 ≤1,63
a
The fatigue limits for samples of unnotched test pieces and notched test pieces in Table 4 are used as
a reference to calculate safety factors in EN 13103-1:2017+A1:2022, which are valid for: q≤1,47 for
EA1N and EA1T and q≤1,63 for EA4T.
4.2.3.3 Fatigue test pieces
Examples of drawings of full-size and reduced dimension test pieces are given in Annex B and are
intended to test a nominal stress as defined in Table 4.
To determine F and F , the test pieces shall be representative of the manufacturing process and product
1 2
group (see Annex K) to qualify.
The full-scale geometries defined in Annex B lead to test a local stress that is between 1,20 and 1,23 times
the nominal stress (i.e. stress concentration factor). In case of failure during this test on an axle with a
different design than the ones described in Annex B, the influence of the test arrangement or this
geometry should be analysed, to verify if they lead to a higher stress concentration factor. If so, the test
should be adapted and repeated, in order to have the same local stress conditions as with the test pieces
described in Annex B.
To determine F , surface of the test pieces shall have a 1 mm deep notch as defined in Figure 3b. All these
test pieces shall be produced using the same manufacturing process as that used for the axle.
To determine R and R , the test pieces shall have a diameter around 10 mm. The surface roughness
fL fE
(Ra) of the test piece for determining R is less than or equal to 0,4 μm. The notch for determining R is
fL fE
defined in Figure 3a. These test pieces are taken as close as possible to the surface of the axle body.
Dimensions in millimetres
a) Notch for determination of R b) Notch for determination of F
fE 2
Figure 3 — Fatigue test piece notches
4.2.3.4 Test method
The tests shall be performed with machines that induce rotating bending stresses in the verification area.
For each limit, F and F , it shall be verified that for three test pieces there is no crack after 10 cycles of
1 2
load that generates a surface stress level equal to F and F . The values of the stresses are nominal
1 2
stresses to be applied at the section corresponding to the inner edge of the wheel seat at the axle body
diameter. They are calculated by classical beam theory in relation to the standard samples for the tests
described in Annex B. Regarding F2 tests, the stresses are nominal stresses calculated at the outer body
diameter in the section of the notch.
Alternatively, the local stresses can be measured by strain gauges. Those local stresses shall be scaled,
through strain concentration factors, to the intended nominal stress to be verified, in the cross-section
where the fatigue cracks initiate. The strain concentration factor should be determined by a static test or
by a dynamic test.
R and R shall be determined for 10 cycles for a non-fracture probability of 50 %, which requires the
fL fE
use of at least 15 test pieces for each limit and a statistical method for the interpretation of the results.
NOTE The number of axles used to obtain the test pieces can be defined in the technical specification.
4.3 Microstructure characteristics
4.3.1 Values to be achieved
The microstructure of EA1N steel grade is derived from normalizing heat treatment and shall be ferritic-
pearlitic.
The microstructure of EA1T steel grade is derived from quenching and tempering heat treatment and
shall be ferritic-pearlitic.
NOTE In some specific cases (e.g. small-size axles), tempered bainite and tempered martensite can be found
The microstructure of EA4T steel grades is derived from quenching and tempering heat treatment and it
shall be tempered bainite and/or tempered martensite. Ferrite and pearlite are permissible.
The grain size of EA1N, EA1T and EA4T (austenite grain size) shall be equal to or finer than that defined
by the reference diagram 5 of EN ISO 643:2012, Annex B.
4.3.2 Position of the test piece
The test pieces shall be taken from the largest axle section in a 200 mm plane, perpendicular to the
arrow F, at mid-radius of solid axles, or at mid-distance between the external and internal surface of
hollow axles, as shown in Figure 4.
For forged axles, when defined in the technical specification, a test piece may be taken from axle journal
extensions as stated in Annex A.
4.3.3 Test method
Tests shall be performed in accordance with EN ISO 643:2012.
4.4 Material cleanliness
4.4.1 Micrographic cleanliness
4.4.1.1 Cleanliness level to be achieved
The level of cleanliness shall be measured by micrographic examination as defined in 4.4.1.2 and 4.4.1.3.
The maximum values of inclusions to be obtained are given in Table 5.
Table 5 — Maximum values of inclusions in fine and thick series
Category 1 Category 2
Type of inclusions
Thick series Thin series Thick series Thin series
(maximum) (maximum) (maximum) (maximum)
A (sulphur) 1,5 1,5 1,5 2
B (Aluminate) 1 1,5 1,5 2
C (Silicate) 1 1,5 1,5 2
D (Globular oxide) 1 1,5 1,5 2
B + C + D 2 3 3 4
DS 1,5 2
4.4.1.2 Position of the micrographic sample
The position of the samples is given in Figure 4.
The examination shall be made in a 200 mm plane, perpendicular to arrow F, at mid-radius of the solid
axles, or at mid-distance between external and internal surface of hollow axles. The test pieces shall be
taken from the largest axle section.
Figure 4 — Position of sample for micrographic examination (solid axle and hollow axle)
For forged axles, when defined in the technical specification test piece may be taken from axle journal
extensions as stated in Annex A.
4.4.1.3 Test method
Cleanliness level determination shall be carried out in accordance with ISO 4967:2013, method A.
4.4.2 Internal integrity
4.4.2.1 General
Internal integrity of the axle in its rough machined or finished state shall be determined by ultrasonic
examination using a mechanized computer-based test process. When the automatic system is
temporarily not available, a manual process can be used, if specified in the technical specification.
Standard defects shall be flat bottom holes at different depths.
4.4.2.2 Level to be achieved
The axles shall have no internal defects that give echo magnitudes equal to or greater than those obtained
for a reference defect situated at the same depth. The diameter of this reference defect shall be 2 mm for
category 1 axles and 3 mm for category 2 axles. No attenuation of the back echo higher than 4 dB due to
inhomogeneities or internal defects shall be accepted.
For the zone 20 mm below the surface, it is recommended, if the ultrasonic inspection equipment enables
it, to record, for information, lower indication size (1 mm for axles of category 1 and 1,5 mm for axles of
category 2).
4.4.2.3 Test piece
The examination shall be made on the axle itself after heat treatment and machining before the final
protection is applied.
If axles are subjected to radial testing in their rough-machined state, they do not need to be tested in their
finished state.
4.4.2.4 Method of examination
The axle internal integrity shall be verified by ultrasonic diametral examination according to
ISO 5948:2018, method Da. The whole axle shall be examined, except certain parts (fillets, grooves, etc.)
in accordance with the technical specification.
4.5 Permeability to ultrasound
4.5.1 Gene
...
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