SIST-TS CEN/TS 15718:2011
(Main)Railway applications - Wheelsets and bogies - Product requirements for cast wheels
Railway applications - Wheelsets and bogies - Product requirements for cast wheels
This technical standard specifies the characteristics of cast railway wheels for use on European networks.
Two steel grades, C ER7 and C ER8, are defined in this Technical Specification. For tread-braked wheels; only C ER7 is used.
This Technical Specification is applicable to cast wheels which have a chilled rim. The standard is only applicable to cast wheels that have satisfied the technical approval procedure according to CEN/TS 13979-2.
This Technical Specification applies only to wheels used in freight wagon applications for speeds up to and including 120 km/h.
Bahnanwendungen - Radsätze und Drehgestelle - Produktanforderungen für Gussräder
Diese Technische Spezifikation legt die Merkmale von gegossenen Eisenbahnrädern fest, die auf europäischen Streckennetzen verwendet werden sollen.
In dieser Technischen Spezifikation werden zwei Stahlgüten, CER7 und CER8 definiert. Für über die Laufflächen gebremste Räder wird nur CER7 verwendet.
Diese Technische Spezifikation ist auf Gussräder mit gehärteten Radreifen anwendbar. Diese Technische Spezifikation ist nur auf Gussräder anwendbar, die das technische Genehmigungsverfahren nach CEN/TS 13979-2 erfüllt haben.
Diese Technische Spezifikation gilt nur für Räder, die in Güterwagenanwendungen für Geschwindigkeiten bis zu einschließlich 120 km/h verwendet werden.
Applications ferroviaires - Essieux montés et bogies - Exigences pour roues en acier moulé
La présente spécification technique spécifie les caractéristiques des roues en acier moulé équipant les véhicules ferroviaires utilisés sur les réseaux européens.
La présente spécification technique définit deux nuances d’acier, C ER7 et C ER8. Pour les roues équipées de freins à semelles, seule la nuance C ER7 est utilisée.
La présente spécification technique s’applique aux roues en acier moulé munies d’une jante traitée en surface. Elle s’applique uniquement aux roues en acier moulé ayant satisfait à la procédure d’homologation technique selon la CEN/TS 13979-2.
La présente spécification technique s’applique uniquement aux roues utilisées dans les applications des wagons fret à des vitesses inférieures ou égales à 120 km/h.
Železniške naprave - Kolesne dvojice in podstavni vozički - Zahtevane lastnosti za lita kolesa
Ta evropski standard določa značilnosti litih železniških koles za uporabo v evropskih omrežjih.
V tem standardu sta določena dva razreda jekla, C ER7 in C ER8. Za kolesa s profilno zavoro se uporablja le C ER7.
Ta standard velja za lita kolesa z ohlajenim platiščem. Standard velja le za lita kolesa, ki so prestala postopek tehnične odobritve v skladu s FprEN 13979-2.
Ta standard velja le za kolesa, ki se uporabljajo za aplikacije tovornih vagonov za hitrosti do vključno 120 km/h.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2011
äHOH]QLãNHQDSUDYH.ROHVQHGYRMLFHLQSRGVWDYQLYR]LþNL=DKWHYDQHODVWQRVWL]D
OLWDNROHVD
Railway applications - Wheelsets and bogies - Product requirements for cast wheels
Bahnanwendungen - Radsätze und Drehgestelle - Produktanforderungen für Gussräder
Applications ferroviaires - Essieux montés et bogies - Exigences pour roues en acier
moulé
Ta slovenski standard je istoveten z: CEN/TS 15718:2011
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.
TECHNICAL SPECIFICATION
CEN/TS 15718
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
September 2011
ICS 45.040
English Version
Railway applications - Wheelsets and bogies - Product
requirements for cast wheels
Applications ferroviaires - Essieux montés et bogies - Bahnanwendungen - Radsätze und Drehgestelle -
Exigences pour roues en acier moulé Produktanforderungen für Gussräder
This Technical Specification (CEN/TS) was approved by CEN on 3 January 2011 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15718:2011: E
worldwide for CEN national Members.
Contents Page
Forew ord .4
Introduction .5
1 Scope .6
2 Normative references .6
3 Product definition .7
3.1 Chemical composition .7
3.1.1 Values to be achieved .7
3.1.2 Location of the sample .7
3.1.3 Chemical analysis .7
3.2 Mechanical characteristics .7
3.2.1 Tensile test characteristics .7
3.2.2 Hardness characteristics in the rim .9
3.2.3 Impact test characteristics .10
3.2.4 Fatigue characteristics .10
3.2.5 Fracture toughness characteristics of the rim .11
3.3 Heat treatment homogeneity .12
3.3.1 Location of measurement .12
3.3.2 Values to be achieved .12
3.3.3 Test method .12
3.4 Metallurgical structure .12
3.5 Material cleanliness .12
3.5.1 Micrographic cleanliness .12
3.5.2 Internal integrity .13
3.6 Residual stresses .16
3.6.1 General .16
3.6.2 Values to be achieved .16
3.6.3 Test piece .17
3.6.4 Measurement methods .17
3.7 Surface characteristics .17
3.7.1 Surface appearance .17
3.7.2 Surface integrity .17
3.8 Geometric tolerances .18
3.9 Static imbalance .20
3.10 Shot peening - Requirements .20
3.10.1 General .20
3.10.2 Values to be achieved .21
3.10.3 Measurement method .21
3.11 Protection against corrosion .21
3.12 Wheel maintenance capacity .21
3.13 Manufacture’s markings .21
Annex A (normative) Hydrogen control at the point of steel melt for monobloc wheels .23
A.1 Sampling .23
A.2 Analysis methods .23
A.3 Operating precautions .23
Annex B (informative) Example of a test method for the determination of fatigue characteristics .24
B.1 Test piece .24
B.2 Test rig .24
B.3 Test monitoring .24
B.4 Analysis of results .24
Annex C (informative) Strain gauge method for determining the variation of circumferential
residual stresses located deep under the tread (destructive method) . 25
C.1 Principle . 25
C.2 Procedure . 25
C.2.1 Fitting of a rim cross section with strain gauges prior to wheel cutting . 25
C.2.2 Execution of cutting . 25
C.2.3 Operations to be executed during cutting . 26
C.3 Expression of results . 26
C.3.1 Calculation of the variation of the circumferential residual stress located deep under the
tread . 26
C.3.2 Calculation of the variation of the circumferential stress created by cutting operation 1 . 26
C.3.3 Calculation of the variation of the circumferential stress created by cutting operation 2 . 27
C.3.4 Calculation of the variation of the circumferential stress created by cutting operation 3 . 27
C.3.5 Final diagram representing the variation of the circumferential stress located deep under
the tread . 27
Annex D (informative) Product qualification . 31
D.1 General . 31
D.2 Requirements . 31
D.2.1 Requirements for the producer . 31
D.2.2 Requirements for the product . 32
D.3 Qualification procedure . 32
D.3.1 General . 32
D.3.2 Documentation required . 32
D.3.3 Evaluation of manufacturing equipment and of the production processes . 33
D.3.4 Laboratory tests . 33
D.3.5 Testing of wheels . 34
D.4 Qualification certificate . 34
D.4.1 Condition of the validity . 34
D.4.2 Modification and extension . 34
D.4.3 Transference . 35
D.4.4 Lapsed certificate . 35
D.4.5 Cancellation . 35
D.5 Qualification documents . 35
Annex E (informative) Product delivery . 36
E.1 General . 36
E.2 Delivery condition . 36
E.3 Controls on each wheel . 37
E.4 Batch control . 37
E.4.1 Controls . 37
E.4.2 Uniformity of batches by measurement of rim hardness . 38
E.4.3 Orientation of residual stresses on rim chilled wheels . 39
E.4.4 Shot peening . 39
E.4.5 Visual inspection . 40
E.4.6 Quality plan . 40
E.5 Allowable rectification . 41
Bibliography . 42
Foreword
This document (CEN/TS 15718:2011) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
Your attention is drawn to the fact that certain elements in this document may be subject to intellectual
property or similar rights. CEN and/or CENELEC cannot be held responsible for not identifying such property
rights and providing a warning of their existence.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive 2008/57/CE.
According to CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Croatia, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Iceland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Norway, the Netherlands, Poland, Portugal, Romania, Slovakia,
Slovenia, Spain, Sweden, Switzerland and the United Kingdom.
Introduction
Prior to the publication of this Technical Specification, the only European Standard available to define quality
requirements for monobloc wheels was EN 13262, which applies only to forged and rolled wheels. Forging
and rolling was the only authorized process to be used by the UIC regulation that was applicable in the recent
past for European countries.
Cast wheels are commonly used by AAR networks and have been introduced into Europe on some
applications for freight wagons. As a reference document, this standard defines the product requirements of a
monobloc cast wheel. In order for a cast wheel to maintain the same level of safety as for a forged and rolled
wheel, for the product characteristics, the main content of this document is derived from EN 13262.
This standard addresses a complete definition of the product and delivery procedures for cast wheels by:
a) defining all the wheel characteristics;
NOTE 1 These are either verified during the qualification or for the delivery of the product (see Clause 3).
b) defining qualification procedures (see Annex D);
c) defining delivery conditions (see Annex E).
NOTE 2 A choice is given to the supplier, of either:
1) a traditional delivery procedure with a control by batch sampling as in existing documents (see E.4) or;
2) delivery procedure using quality assurance concepts (see E.4.6).
.
1 Scope
This technical standard specifies the characteristics of cast railway wheels for use on European networks.
Two steel grades, C ER7 and C ER8, are defined in this Technical Specification. For tread-braked wheels;
only C ER7 is used.
This Technical Specification is applicable to cast wheels which have a chilled rim. The standard is only
applicable to cast wheels that have satisfied the technical approval procedure according to CEN/TS 13979-2.
This Technical Specification applies only to wheels used in freight wagon applications for speeds up to and
including 120 km/h.
2 Normative references
The following referenced documents are indispensable for the application 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 13262, Railway applications — Wheelsets and bogies — Wheels — Product requirements
EN 10045-1, Metallic materials — Charpy impact test — Part 1: Test method
EN ISO 148-1, Metallic materials - Charpy pendulum impact test - Part 1: Test method (ISO 148-1:2009)
EN ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method (ISO 6506-1:2005)
EN ISO 6892-1, Metallic materials ― Tensile testing. Part 1: Method of test at room temperature
(ISO 6298-1:2009).
ISO 1101, Geometrical Product Specifications (GPS) – Geometrical tolerancing -- Tolerances of form,
orientation, location and run-out.
ISO 5948:1994, Railway rolling stock material — Ultrasonic acceptance testing
ISO 6933:1986, Railway rolling stock material — Magnetic particle acceptance testing
1)
ISO/TR 9769 , Steel and iron — Review of available methods of analysis
ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition
ASTM E 399-90:1990, Test method for plane-strain fracture toughness of metallic materials
ASTM E1245, Standard Practice for Determining the Inclusion or Second-Phase Constituent Content of
Metals by Automatic Image Analysis
SAE J827, High-carbon cast-steel shot
SAE J442, Test strip, holder and gage for shot peening
SAE J443, Procedures for using standard shot peening test strip
1) See also CEN report CR 10261:1995.
SAE J444, Cast shot and grit size specifications for peening and cleaning
3 Product definition
When the characteristics of the wheel vary as a result of the casting process, the test pieces shall be taken
from the worst-case location. The worst-case location has to be defined during the product qualification
process by means of comparative tests in different parts of the wheel (feeder head area, outside feeder head
area, intermediate). These defined locations are valid for a given manufacturing process and used for the
ongoing production. In the case of a process change, these locations will have to be defined again.
3.1 Chemical composition
3.1.1 Values to be achieved
The maximum percentage contents of the various elements contained within cast wheels shall be as given in
Table 1.
Table 1 — Maximum content of various elements within cast wheels
Steel Maximum content
grade
%
c a a, b c
C Si Mn P S Cr Cu Mo Ni V Cr +
Mo +
Ni
CER7 0,52 0,6 0,80 0,020 0,02 0,30 0,30 0,12 0,30 0,06 0,52
CER8 0,56 0,6 0,80 0,020 0,02 0,30 0,30 0,12 0,30 0,06 0,52
NOTE For special applications, variations within the maximum limit of these values may be agreed.
a
A maximum content of 0,025 % may be agreed at the time of enquiry or order.
b
A minimum sulfur content may be agreed at the time of enquiry and at the time of order in order to
safeguard against hydrogen cracking.
c
These values exceed those in EN 13262. It shall be ensured that use of these values does not
adversely affect the metallurgical structure of the wheel.
3.1.2 Location of the sample
The sample used for determining the chemical composition shall be taken 15 mm below the tread at its
nominal diameter.
3.1.3 Chemical analysis
The chemical composition analysis shall be performed according to methods and definitions that are
described in ISO/TR 9769.
3.2 Mechanical characteristics
3.2.1 Tensile test characteristics
3.2.1.1 Values to be achieved
Cast wheels shall have rim and web characteristics of at least the values given in Table 2.
Table 2 — Minimum tensile test values of the rim and web
Steel grade Rim Web
a b
R ≥ R A ≥ R reduction ≥ A ≥
m
eH 5 m 5
2 2 2
N/mm N/mm % N/mm %
CER7 ≥ 520 820/940 ≥ 14 ≥ 110 ≥ 16
CER8 ≥ 540 860/980 ≥ 13 = 120 ≥ 16
a
If no distinctive yield strength is present, the proof stress R shall be determined.
p0,2
b
Reduction of tensile strength as compared to that of the rim on the same wheel.
3.2.1.2 Location of test pieces
Test pieces shall be taken from the rim and the web of the wheel, as indicated in Figure 1.
Dimensions in millimetres
Key
1 tensile test piece
2 tensile test piece
3 impact test piece
4 nominal diameter
5 notch
Figure 1 — Location of test pieces
3.2.1.3 Test method
This shall be performed in accordance with EN ISO 6892-1. The test piece diameter shall be at least 10 mm in
the parallel length and the gauge length shall be 5 times the diameter.
NOTE If the wheel design prevents a sample of the stated size from being taken, a smaller sized sample may be
taken after agreement between the customer and supplier.
3.2.2 Hardness characteristics in the rim
3.2.2.1 Values to be achieved
Minimum values of Brinell hardness applicable to the whole wear zone of the rim shall be as given in Table 3.
These values shall be achieved up to a maximum depth of 35 mm under the tread, even if the wear depth is
higher than 35 mm. These measurements shall be taken from the points defined by B, C and D in Figure 2.
Hardness values in the rim-web transition (point A in Figure 2) shall be at least 10 points lower than the wear
limit values.
Table 3 — Minimum hardness values
Steel grade Minimum value for Brinell hardness
CER7 235
CER8 245
3.2.2.2 Location of readings
Four readings shall be carried out on a radial section of the rim as shown in Figure 2. Where the
microstructure of the wheel varies as a result of the casting process, the test locations shall occur in the worst-
case areas of the wheel.
Dimensions in millimetres
Key
1 limit of wear or last turning diameter (according to customer’s requirements)
2 inside surface of finished wheel
3 nominal diameter
Figure 2 — Readings taken on a radial section of the rim
3.2.2.3 Test method
This shall be performed in accordance with EN ISO 6506-1. The ball diameter is 5 mm.
3.2.3 Impact test characteristics
3.2.3.1 Values to be achieved
Cast wheels shall have the average and minimum impact values as given in Table 4.
NOTE The values represent the average and minimum values for the three test specimens defined in 3.2.3.2.
At +20 °C, U-notch specimens shall be used. At -20 °C, V-notch specimens shall be used.
Table 4 — Average and minimum impact test characteristics
Steel grade KU (J) at +20 °C KV (J) at -20 °C
Average values Minimum values Average values Minimum values
CER7 ≥ 17 ≥ 12 ≥ 10 ≥ 7
CER8 ≥ 17 ≥ 12 ≥ 10 ≥ 5
3.2.3.2 Location of the test pieces
Test pieces shall be taken from the rim of the wheel, as indicated in Figure 1.
The bottom notch axis shall be parallel to the A-A axis of Figure 1.
3.2.3.3 Test method
This shall be performed in accordance with EN 10045-1.
3.2.4 Fatigue characteristics
3.2.4.1 Values to be achieved
Regardless of the steel grade, the web shall withstand the stress variation, Δσ, given in Table 5 during 10
cycles without any crack initiation, with a probability of 99,7 %.
Table 5 — Minimum fatigue characteristics
State of delivery of the web
Δσ
N/mm
Fully machined 450
Partially machined or as cast and 315
shot peened
NOTE 1 The aim of these characteristics is to ensure that product characteristics are higher than those used for the
definition of permissible stresses for the fatigue design of the web.
NOTE 2 As there are many approximations in a fatigue calculation, it is not realistic to distinguish between the two
steel grades.
3.2.4.2 Specimens for fatigue test
Specimens shall consist of wheels as delivered. Their surface appearances shall be those defined in 3.7.
3.2.4.3 Test method
The test method shall allow bending stresses to be created in a web section.
The tests to demonstrate the fatigue properties shall be performed in such a manner that statistical evaluation
to assess the results can be applied.
Tests shall be monitored by measuring the radial stresses which exist in the crack initiation area.
NOTE An example of the method is given in Annex B.
3.2.5 Fracture toughness characteristics of the rim
3.2.5.1 General
This characteristic shall only be verified on tread-braked wheels (service brake or parking brake).
3.2.5.2 Values to be achieved
For steel grade CER7, the average value obtained from six test pieces shall be greater than or equal to
2 2
80 N/mm m and any single value shall not be below a minimum of 70 N/mm m .
3.2.5.3 Location of test pieces
Six test pieces shall be taken from the rim as indicated in Figure 3. Where the microstructure of the wheel
varies as a result of the casting process, the test locations shall be in the worst-case areas of the wheel.
Dimensions in millimetres
Key
1 nominal diameter
Figure 3 — Test pieces taken from the rim
3.2.5.4 Test method
The test shall be performed according to ASTM E 399-90.
The test conditions shall be as follows:
a) the compact specimen shall have a CT thickness of 30 mm (CT 30 specimen), with chevron notch having
an aperture angle of 90° (see Figure 4 of ASTM E 399.90);
b) temperature during the test between +15 °C and +25 °C;
c) measurement of the crack displacement of the specimen as indicated in Figure 3 of ASTM E 399.90;
d) rate of increase of stress intensity, ΔK/s (stress intensity per second), shall be within the range
2 2
0,55 N/mm√m/s to 1 N/mm√m/s (see 8.3 of ASTM E 399-90);
e) the value of the toughness to be considered shall be the value K which is calculated from the value of
Q
the load F from the load-displacement record.
Q
3.3 Heat treatment homogeneity
3.3.1 Location of measurement
The hardness measurements shall be taken at three points on the outside surface of the rim. Where the
casting process uses risers (see Note), the test locations shall occur both in-line and between the riser
positions.
The impressions shall be made on a same diameter in the area located as defined in Figure E.1.
NOTE Risers are defined in this document as the reservoir of molten metal from which the casting feeds as it shrinks
during solidification.
3.3.2 Values to be achieved
The hardness value variation shall be within a 30 HB range for a wheel.
3.3.3 Test method
The test shall be performed in accordance with EN ISO 6506-1. The ball diameter is 10 mm.
3.4 Metallurgical structure
The absence of bainitic structure shall be checked by a micrographic examination.
3.5 Material cleanliness
3.5.1 Micrographic cleanliness
3.5.1.1 Sample size and location
A minimum of six samples shall be taken from each wheel tested approximately equidistant around the
circumference of the wheel. Each sample shall be 22 mm wide in the circumferential direction (the running
direction) and 13 mm thick in the radial direction (that of the rim thickness). Its centre F shall be located
15 mm below the wheel tread and 70 mm from the back rim face as shown in Figure 4.
Dimensions in millimetres
Key
C nominal wheel tread
F centre of sample
Figure 4 — Location of sample for the micrographic examination
3.5.1.2 Sample preparation
Each 22 mm x 19 mm x 13 mm sample shall be meticulously prepared and evaluated to ASTM E1245. The
flicker method shall be used to establish the correct setting of the grey-level threshold limits.
The total area evaluated for each sample shall be not less than 161 mm . All inclusions greater than 2,5 μm
shall be counted.
3.5.1.3 Level to be achieved
The average and worst field area percentage of inclusions and voids shall be recorded.
The maximum permissible values for the six samples are:
⎯ 0,1 % for the average inclusions plus voids;
⎯ 0,75 % for the worst field, inclusions plus voids.
NOTE The criteria of these characteristics have to be confirmed by in-service experience of wheels to demonstrate
that there is no fatigue crack propagation beneath the tread.
3.5.2 Internal integrity
3.5.2.1 General
Internal integrity shall be determined from ultrasonic examination. The examination shall be carried out before
shot peening.
Standard defects are flat bottom holes with different diameters.
3.5.2.2 Level to be achieved
3.5.2.2.1 Rim
The rim shall have no internal defects that give echo magnitudes higher than or equal to those obtained for a
standard defect situated at the same depth. The diameter of this standard defect shall be 2 mm.
There shall be no attenuation of the back echo higher than 4 dB during axial examination.
3.5.2.2.2 Web
The web shall not have:
a) more than 10 echoes with magnitudes greater than or equal to those obtained for standard defects of
diameter 3 mm;
b) echoes with magnitudes greater than or equal to those obtained for standard defects of diameter 5 mm.
The distance between two acceptable defects shall be at least 50 mm.
3.5.2.2.3 Hub
The hub shall not have:
a) more than 3 echoes of magnitude greater than or equal to those obtained for standard defects of 3 mm
diameter;
b) echoes of magnitude greater than or equal to those obtained for standard defects of 5 mm diameter.
The distance between two acceptable defects shall be at least 50 mm.
For one circumferential examination, no attenuation of the back echo equal to or greater than 6 dB shall be
permitted.
3.5.2.3 Test piece
Examination shall be made of the complete wheel, after heat treatment, either before shot peening or before
any anti-corrosion protection is applied.
3.5.2.4 Method of examination
3.5.2.4.1 General
Samples shall undergo ultrasonic examination in accordance with ISO 5948 in accordance with the following
special conditions of 3.5.2.4.2, 3.5.2.4.3 and 3.5.2.4.4.
3.5.2.4.2 Rim
The rim examination shall be made in accordance with ISO 5948:1994, Table 1 methods D and D .
1 2
Defect estimation shall be made by comparison to artificial defects in the standard rim in accordance with
ISO 5948:1994, Figures 1 and 2.
In addition, ultrasonic examination shall be performed to cover the rim to web transition.
3.5.2.4.3 Web
The web examination shall be made on both faces. The direction of the examination is perpendicular to the
surface.
Defect estimation shall be made by comparison to artificial defects in a standard web.
The web shall be defined as the part of the wheel between the two diameters at “m” and “n” (see Figure 6).
The thickness, “e”, of the web shall be defined with the following equation:
m+ n
⎛ ⎞
e=
⎜ ⎟
⎝ ⎠
where
e is the thickness of the web;
m is the thickness at the connection with the rim at diameter "m";
n is the thickness at the connection with the hub at diameter "n".
The location of the artificial defects shall be given as a function of e. They shall be at least 100 mm apart in a
circumferential orientation.
⎯ e ≤ 10 mm
⎯ One 3 mm diameter flat bottom hole located 5 mm below the inner surface of the web
⎯ One 5 mm diameter flat bottom hole located 5 mm below the inner surface of the web
⎯ 10 mm < e ≤ 20 mm
⎯ Two 3 mm diameter flat bottom holes located 5 mm and (e - 5) mm below the inner surface of the
web
⎯ Two 5 mm diameter flat bottom holes located 5 mm and (e - 5) mm below the inner surface of the
web
⎯ e > 20 mm
⎛ e⎞
⎯ Three 3 mm diameter flat bottom holes located 5 mm, mm and (e – 5) mm below the inner
⎜ ⎟
⎝ ⎠
surface of the web
e
⎛ ⎞
⎯ Three 5 mm diameter flat bottom holes located 5 mm, mm and (e – 5) mm below the inner
⎜ ⎟
⎝ ⎠
surface of the web
3.5.2.4.4 Hub
The hub examination shall be made on both faces. The direction of the examination shall be perpendicular to
the surface.
Defect estimation shall be made by comparison to artificial defects in the standard hub shown in Figure 5.
Calibration references are:
⎯ 3 standard defects of diameter 3 mm located at different depths;
⎯ 3 standard defects of diameter 5 mm located at different depths.
Spacing as shown below.
Figure 5 — Standard hub for ultrasonic examination
3.6 Residual stresses
3.6.1 General
Wheel heat treatment shall induce a compressive circumferential residual stress field inside the rim.
3.6.2 Values to be achieved
The level of compressive circumferential stresses shall be measured near the surface of the tread and shall
2 2
be in the range 80 N/mm to 150 N/mm . These stresses shall be equal to zero between 35 mm and 50 mm.
NOTE The stress distribution is shown in Figure 6 below the tread.
Figure 6 — Range in variation of circumferential stress values
3.6.3 Test piece
The test piece shall be the complete wheel after heat treatment.
3.6.4 Measurement methods
Measurement methods shall estimate the variation of circumferential stresses located deep under the tread.
This method shall be agreed between the supplier and the customer.
Annex C gives an example method that can be used for this measurement; the stress distribution values given
in Figure 6 shall be applied to this method.
3.7 Surface characteristics
3.7.1 Surface appearance
3.7.1.1 Characteristics to be achieved
The wheel surface shall not show any marks other than those at the positions stipulated in this Technical
Specification.
NOTE According to their use, wheels may be fully or part machined.
The “as cast” faces of the web extending approximately one half of the way into the hub and rim fillet radii on
the front and on the back of the wheel shall be shot peened.
Average surface roughness (R ) area values of “finished” or “ready for assembly” wheels shall be as given in
a
Table 6.
Table 6 — Average surface roughness
a
Area of the wheel State of delivery Roughness, R
a
μm
Bore Finished
≤ 12,5
b
Ready for assembly 0,8 to 3,2
c
Web and hub Finished ≤ 12,5
c
Rim tread Finished
≤ 6,3
c
Rim faces Finished ≤ 6,3
a
See F.2.
b
If the wheel has to be fitted on a hollow axle, other values may be required for the purpose of the
in-service ultrasonic inspection.
c
If defined in the order, this area of the wheel may remain unmachined, provided the tolerances
indicated in this table are achieved.
3.7.1.2 Measurement method
The roughness of the wheel surfaces (R ) at the delivery stage indicated in Table 6 shall be inspected by
a
comparison with the roughness specimen described or measured with a profile meter on the plane surface.
3.7.2 Surface integrity
3.7.2.1 General
Surface integrity shall be determined by a magnetic particle test of the web, carried out in accordance
with 3.7.2.4 and visual inspection (for porosity and other visible defects) both in the web and elsewhere.
3.7.2.2 Level to be achieved
The maximum indicated length of permissible surface breaking defects on a finished wheel shall be 2 mm.
3.7.2.3 Test piece
Examination shall be made on the complete wheel after heat treatment and after shot cleaning, but before
shot peening and before the application of any temporary corrosion protection.
3.7.2.4 Methods of inspection
General requirements for the magnetic particle test shall be defined in accordance with ISO 6933 with the
following exceptions:
a) the level of surface magnetic induction shall be greater than 4 mT;
b) the level of ultra-violet light energy shall be greater than 15 W/m².
The magnetisation method shall be performed in accordance with ISO 6933:1986, Figure 2c. The apparatus
used shall scan the entire wheel surface and be able to detect the defects whatever their orientation.
3.8 Geometric tolerances
The geometry and dimensions of wheels shall be defined by a drawing included with the order.
The geometric tolerances shall conform to those given in Table 7.
The symbols used in Table 7 are defined in Figure 7.
Table 7 — Geometric tolerances
a
Designation Symbols Values (mm)
b
Dimensions Geometric Unmachined Finished
Rim
External diameter a 0 / +4
Internal diameter (outer) b 0 / -4
Internal diameter (inner) b 0 / -6 0 / -4
Width d ± 1
e
Tread profile v
≤ 0,5
Circularity of the tread s ≤ 0,2
Total run out in axial direction t
≤ 0,3
Total run out in radial direction j ≤ 0,2
of the jaw hold
External diameter of the w 0 / +2
groove (i.e. wear line)
Hub External diameter (outer) f 0 / +10 0 / +5
External diameter (inner) f 0 / +10 0 / +5
Internal diameter of the bore:
c
“Finished” g 0 / -2
c
“Finished ready for assembly” g In accordance with the drawing or a
standard to ensure the interference fit
Cylindricity of internal diameter
of the bore:
c
“Finished” x
1 ≤ 0,2
c
d
“Finished ready for assembly” x ≤ 0,02
Length h 0 / +2
Hub to wheel overhang r 0 / +2
Total run out of the diameter of
the bore:
c
“Finished” Q1
≤ 0,2
c
“Finished ready for assembly” Q2
≤ 0,1
Web Position for the web at the K ≤8 ≤ 8
connection with the rim and the
hub
Thickness at the connection m +8 / 0 + 5 / 0
with the rim
Thickness at the connection n +10 / 0 + 5 / 0
with the hub
a
See Figure 7
b
See EN ISO 1101
c
See E.2 for terms related to bore of the hub
d
Any slight taper within the permitted tolerance shall be such as the “larger” diameter is at the axle entry end of
the bore on assembly of the wheel on the axle
e
From the top of the flange as far as the external chamfer
Figure 7 — Symbols
3.9 Static imbalance
The maximum static imbalance of a finished wheel in the delivery condition shall be ≤ 125 g·m (symbol E3).
The means and methods of measurement shall be agreed between the customer and the supplier.
3.10 Shot peening - Requirements
3.10.1 General
This subclause covers the shot peening of cast wheels intended to improve the web fatigue strength.
The shot shall be the Society of Automotive Engineers shot designated SAE No. 550 or a larger hardened
steel as specified in the Society of Automotive Engineers technical standards SAE J827 and SAE J444.
All the wheels shall be subjected to shot peening after completion of the corrective operations to the surfaces
in the web area as specified in 3.7.1.1.
A portable peening device may be used to re-peen small reconditioned areas no larger than about
50 mm x 75 mm on wheel web surfaces excluding the critical fillet areas (front hub and back rim).
3.10.2 Values to be achieved
3.10.2.1 Fixed installations
The peening machines shall be equipped with a separator for continuously removing broken shot. Sufficient
new shot shall be added to ensure that a minimum of 85 % of SAE No. 550 or larger shot is maintained in the
machines at all times.
The peening intensity shall be sufficient to produce an average arc height of not less than 0,008 (0,0075+)
Almen C-2 within the zones defined in 3.7.1.1.
3.10.2.2 Portable equipment
Portable peening equipment shal
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...