SIST EN 16771:2017
(Main)Railway applications - Infrastructure - Aluminothermic welding of grooved rails
Railway applications - Infrastructure - Aluminothermic welding of grooved rails
This standard defines the laboratory tests and requirements for approval of an aluminothermic welding process using welds produced in workshop conditions.
It applies to the joining of new, grooved rails as described in EN 14811 of the same profile and steel grade. Welding of construction profiles and machined profiles are not covered in this standard.
Compliance with the requirements of this standard does not of itself ensure the suitability of a welding process for specific conditions of track and traffic.
The standard does not cover welds made between different rail sections, worn rails or different rail grades.
In addition to the definitive requirements this standard also requires the items detailed in Clause 4 to be documented. For compliance with this standard, it is important that both the definitive requirements and the documented items be satisfied.
Bahnanwendungen - Infrastruktur - Aluminiothermisches Schweißen von Rillenschienen
Diese Norm legt Laborprüfungen und Anforderungen zur Zulassung eines aluminothermischen Schweißverfahrens unter Verwendung von Schweißungen fest, die unter Werkstattbedingungen hergestellt wurden.
Diese Norm umfasst die Verbindung neuer Rillenschienen, wie in EN 14811 beschrieben, des gleichen Profils und der gleichen Stahlsorte. Das Schweißen von Bauprofilen und bearbeiteten Profilen wird in dieser Norm nicht behandelt.
Die Erfüllung der Anforderungen dieser Norm bedingt jedoch nicht notwendigerweise die Eignung des Schweißprozesses unter den spezifischen Bedingungen von Oberbau und Betrieb.
Die Norm berücksichtigt keine Schweißungen unterschiedlicher Schienenquerschnitte, unterschiedlich abgenutzter Schienen und unterschiedlicher Stahlsorten.
Zusätzlich zu den in dieser Norm festgelegten Anforderungen sind gleichfalls die in Abschnitt 4 aufgeführten Angaben zu dokumentieren. Für die Konformität mit dieser Norm ist es wichtig, sowohl die festgelegten Anforderungen als auch die Dokumentation der Angaben zu erfüllen.
Applications ferroviaires - Infrastructures - Soudage par aluminothermie des rails à gorge
La présente norme définit les essais de laboratoire et les exigences pour l’approbation d’un procédé de soudage des rails par aluminothermie effectués dans des conditions opératoires d’atelier.
Elle s'applique à l'assemblage de rails à gorge neufs, tels que décrits dans l'EN 14811, de même profil et de même nuance d'acier. Elle ne traite pas du soudage des profils de construction et des profils usinés.
La conformité aux exigences de la présente norme n’assure pas par elle-même l’aptitude à l’emploi d’un procédé de soudage dans des conditions spécifiques de voie ferrée et de trafic.
La présente norme ne s'applique pas au soudage des rails de profils, d'usures ou de nuances différentes.
Outre les exigences définitives, la présente norme exige également que les éléments détaillés à l'Article 4 soient documentés. Pour être conforme à la présente norme, il est important que les exigences définitives ainsi que les éléments à documenter soient remplis.
Železniške naprave - Infrastruktura - Aluminotermično varjenje tirnice z žlebom
Ta standard opredeljuje laboratorijske preskuse in zahteve za odobritev postopka aluminotermičnega varjenja z uporabo zvarov, izdelanih v delavnici.
Uporablja se za združevanje novih tirnic z žlebom, kot je opisano v standardu EN 14811, istega profila in razreda jekla. Varjenje konstrukcijskih in strojnih profilov ni obravnavano v tem standardu.
Skladnost z zahtevami iz tega standarda sama po sebi še ne zagotavlja ustreznosti postopka varjenja za določene pogoje glede proge in prometa.
Standard ne obravnava zvarov, izdelanih iz različnih delov tirnic, obrabljenih tirnic ali različnih razredov tirnic.
Poleg dokončnih zahtev ta standard zahteva tudi, da so postavke, opredeljene v točki 4, dokumentirane. Za skladnost s tem standardom je pomembno, da so izpolnjene tako dokončne zahteve kot dokumentirane postavke.
General Information
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Bahnanwendungen - Infrastruktur - Aluminiothermisches Schweißen von RillenschienenApplications ferroviaires - Infrastructures - Soudage par aluminothermie des rails à gorgeRailway applications - Infrastructure - Aluminothermic welding of grooved rails45.080Rails and railway components25.160.10Varilni postopki in varjenjeWelding processesICS:Ta slovenski standard je istoveten z:EN 16771:2016SIST EN 16771:2017en,fr,de01-januar-2017SIST EN 16771:2017SLOVENSKI
STANDARD
SIST EN 16771:2017
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16771
November
t r s x ICS
t wä s x rä s râ
{ uä s r r English Version
Railway applications æ Infrastructure æ Aluminothermic welding of grooved rails Applications ferroviaires æ Infrastructures æ Soudage par aluminothermie des rails à gorge
Bahnanwendungen æ Infrastruktur æ Aluminothermisches Schweißen von Rillenschienen This European Standard was approved by CEN on
s w July
t r s xä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
9
t r s x CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s x y y sã t r s x ESIST EN 16771:2017
EN 16771:2016 (E) 2 Contents Page European foreword. 4 Introduction . 5 1 Scope . 6 2 Normative references . 6 3 Terms and definitions . 6 4 Information to be supplied by the railway authority . 7 5 Approval procedure . 7 5.1 General . 7 5.2 Process identification . 7 5.3 General requirements . 7 5.4 Documents to be submitted with the request for approval . 8 5.5 Initial compliance testing . 9 5.6 Extension of initial compliance testing . 11 5.7 Preparation and allocation of test welds . 11 6 Re-approval following process changes . 12 7 Laboratory tests. 15 7.1 Visual surface examination . 15 7.1.1 Ascast weld surface . 15 7.1.2 Ground weld surface . 15 7.2 Running surface hardness test . 16 7.3 Slow bend test . 16 7.4 Internal examination . 17 7.4.1 Weld soundness . 17 7.4.2 Fusion zone – Shape and dimension. 19 7.4.3 Microscopic examination . 19 7.4.4 Heat softened zone width . 20 7.5 Chemical analysis . 20 Annex A (informative)
Steps in approval . 22 Annex B (informative)
Suggested sequence of laboratory tests . 24 Annex C (informative)
Procedure for FRY etching . 25 Annex D (normative)
Procedure for measurement of surface hardness . 26 Annex E (normative)
Procedure for slow bend test . 27 Annex F (normative)
Procedure for recording test weld fracture face defects . 29 Annex G (normative)
Ultrasonic inspection procedure on aluminothermic welds to be sectioned . 30 G.1 Principle . 30 G.2 Apparatus . 30 G.3 Preparation of samples . 30 G.4 Calibration . 30 SIST EN 16771:2017
EN 16771:2016 (E) 3 G.5 Testing . 30 G.6 Reporting . 31 Annex H (normative)
Procedure for microscopic examination of the visible heat affected zone and fusion zone of welds . 32 Annex I (normative)
Procedure for measurement of the heat softened zone width . 33 I.1 Measurement of hardness . 33 I.2 Evaluation of hardness data . 34 Bibliography . 36
SIST EN 16771:2017
EN 16771:2016 (E) 4 European foreword This document (EN 16771:2016) 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 2017, and conflicting national standards shall be withdrawn at the latest by May 2017. 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. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 16771:2017
EN 16771:2016 (E) 5 Introduction This standard defines the approval procedure for aluminothermic welding processes for grooved rail welding through laboratory tests of welds produced in a workshop. This laboratory approval will provide the railway authority with sufficient information for tests in the track if required. SIST EN 16771:2017
EN 16771:2016 (E) 6 1 Scope This standard defines the laboratory tests and requirements for approval of an aluminothermic welding process using welds produced in workshop conditions. It applies to the joining of new, grooved rails as described in EN 14811 of the same profile and steel grade. Welding of construction profiles and machined profiles are not covered in this standard. Compliance with the requirements of this standard does not in itself ensure the suitability of a welding process for specific conditions of track and traffic. The standard does not cover welds made between different rail sections, worn rails or different rail grades. In addition to the definitive requirements, this standard also requires the items detailed in Clause 4 to be documented. For compliance with this standard, it is important that both the definitive requirements and the documented items be satisfied. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 14811, Railway applications – Track – Special purpose rail – Grooved and associated construction EN ISO 6506-1, Metallic materials - Brinell hardness test - Part 1: Test method (ISO 6506-1) EN ISO 6507-1, Metallic materials - Vickers hardness test - Part 1: Test method (ISO 6507-1) EN ISO 9712, Non-destructive testing - Qualification and certification of NDT personnel (ISO 9712) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 fusion zone area of the weld which has been in a liquid state and which is revealed by etching sections cut through the weld 3.2 visible heat-affected zone HAZ areas on either side of the fusion zone within the rail steel microstructure has been visibly modified by the heat of the welding process as revealed by Fry macro-etching 3.3 heat softened zone part of the HAZ (Heat Affected Zone) characterised by a lower hardness 3.4 flashing flat fin of weld metal located on the rail surface adjacent to the weld collar caused by gaps between the mould and the rail SIST EN 16771:2017
EN 16771:2016 (E) 7 3.5 surface defect any defect visible on the weld surface after normal finishing operations 3.6 internal defect any defect that is revealed by sectioning or on a fracture face following bend testing that has not already been identified as a surface defect 3.7 railway authority railway regulator, or owner of a railway infrastructure, or custodian with a delegated responsibility for a railway infrastructure 3.8 process supplier company which provides an approved aluminothermic welding process in accordance with this standard 4 Information to be supplied by the railway authority The following information shall be fully documented by the railway authority. For compliance with the standard both the definitive requirements specified throughout the standard and the following documented items shall be satisfied: a) which of the width levels of heat-softened zone is required (7.4.4); b) limitations on the pre-heat to comply with the railway authority regulations. 5 Approval procedure 5.1 General An outline of the steps required for compliance to this standard is given in informative Annex A. 5.2 Process identification The approval shall involve a single process identified by: a) the process name; b) a drawing of the pouring system and the casting system; c) the characteristic geometry of the weld collar and riser configuration as given in 5.4.2 and Figure 1; d) the process manual in accordance with 5.4.1. 5.3 General requirements The following requirements shall be met: a) the process shall be capable of being carried out on track and at or near trackside or in a workshop; SIST EN 16771:2017
EN 16771:2016 (E) 8 b) the aluminothermic welding portion shall be packed to avoid the risk of moisture contamination in prescribed storage conditions. The portion shall be identified by markings on the package; c) the mould shall be pre-fabricated for the rail profiles to be welded and be identified by markings on the package; d) the crucible shall be tapped automatically (automatic tapping) and shall have a device to limit spattering; e) pre-heating shall comply with any limitations of the railway authority as specified in Clause 4, b). 5.4 Documents to be submitted with the request for approval When applying for approval, the following documents shall be submitted: 5.4.1 The process manual. The supplier shall produce a manual identifying all the consumable materials and equipment used, as well as the operating method to be followed for all steps of welding. The approval procedure for laboratory tests will not include means of alignment or finishing operations. The manual shall specify the critical parameters of the welding process and their safe bounds, and shall include the following: a) number of people required to carry out the operations; b) diagram of equipment; c) portion for each rail grade and profile; d) rail end preparation requirements; e) nominal gap shall have a tolerance of ± 2 mm for a
¶ 30 mm gap and ± 3 mm for > 30 mm to 50 mm gaps and ± 5 mm for > 50 mm gaps; f) preheating details; g) range of ignition to tap times for the portions; h) critical process timings; i) time (or temperature) before trains can pass; j) safety information. 5.4.2 Drawing with the required measurements. A drawing, as illustrated in Figure 1, which provides the measurements listed below: a) weld collar width (W1). The development of the weld collar shall be fully dimensioned around the weld; b) maximum depth of collar at section B-B (D1 and D2); c) minimum depth of collar at section B-B (d1 and d2); d) riser cross section at foot; SIST EN 16771:2017
EN 16771:2016 (E) 9 e) riser cross section at neutral axis; f) number of risers; g) position of risers. The dimensions W, D and d and cross sectional areas of the risers shall be the nominal dimensions taken from the drawing of the pattern used to produce the moulds.
Key 1 figure showing the width of the weld collar around the weld 2 riser cross section on the neutral axis mm2 3 25 % of the foot width 4 riser cross section at the foot mm2 5 longitudinal axis under the rail foot Figure 1 — Dimensions taken from mould pattern 5.4.3 Chemical analysis ranges and tolerances. The chemical analysis ranges and tolerances shall be in accordance with 7.5.1. 5.5 Initial compliance testing a) For the purposes of approval the standard, rail profiles (see EN 14811) shall be grouped as follows. SIST EN 16771:2017
EN 16771:2016 (E) 10 Table 1 — Rail profile groups 1 New names Former names 57R1 Ph 37 59R1 Ri 59-R10, Ri 59 59R2 Ri 59-R13, Ri 59N 60R1 Ri 60-R10, Ri 60 60R2 Ri 60-R13, Ri 60 N 60R3 Ri 210/95+80 62R1 NP4aM 62R2 NP4aS 63R1 Ri 210/95+80a 67R1 Ph 37a 68G1 70 G Table 2 — Rail profile groups 2 New names Former names 46G1 60 G 51R1 Ri 52-R13, Ri 52 52R1 Ri Ir 53R1 Ri 53-R13, Ri 53 55G1 35 GP 55G2 41 GP 56R1 Ri lc b) Initial compliance with the present standard shall be achieved by undertaking the tests specified in category 1 of Table 3 using not heat treated rail, by using either R200 or R220G1 or R260 grade. Results are valid for the three grades of all rail profiles in either group 1 or group 2. Compliance with all the criteria specified and with the railway authority’s documented requirements specified in Clause 4 shall be demonstrated. A test sequence is outlined in informative Annex B. A test specimen can be used for several different tests. SIST EN 16771:2017
EN 16771:2016 (E) 11 Table 3 — Testing scheme Test Section reference Number of tests Category 1a Category 2b A
Hardness test 7.2 6 5 B
Surface examination – Visual 7.1.1 7.1.2 6 5 C
Slow Bend Test 7.3 6 3 D
Ultrasonic inspection – Annex G 7.4.1.1 2 Nil E
Weld soundness 7.4.1 7.3 2 (2) Nil F
Fusion Zone – Shape and Dimensions 7.4.2 2 Nil G
Chemical analysis 7.5 3 3 H
Heat softened zone – Hardness distribution 7.4.4 2 2 I
Structure – Fusion Zone – Heat affected zone 7.4.3.3 7.4.3.2 2 2 1 1 NOTE () indicates weld soundness evaluation of the fracture face of the slow bend test specimens. a Category 1 Initial tests to be conducted using not heat treated grade on one rail profile from group 1 or 2 (Table 1 or 2). b Category 2 Tests required extending approval for heat treated grades. Tests on one rail profile cover all profile groups approved in categories 1 and 2. 5.6 Extension of initial compliance testing Initial compliance can be extended as follows: The relevant railway authority requirements defined in Clause 4 shall be met for each of the items below: a) to other group of rail profiles listed in Table 1 or 2 [5.5, a)], by doing the tests given in Table 3 category 1 [5.5, b)] on one profile of the appropriate group. Failure of any test shall cause non-compliance for the group of rail profiles being tested; b) to other rail grade by doing the tests given in Table 3 category 2 [5.5, b)]. Failure of any test shall cause non-compliance for that rail grade. Tests on one rail profile cover all profiles in group 1 or 2. 5.7 Preparation and allocation of test welds a) Welds required for the tests shall be produced in accordance with the process manual (5.4.1) under the supervision of the approving authority. Rails to be used for the production of test SIST EN 16771:2017
EN 16771:2016 (E) 12 welds shall be new rails. Fifty percent of test welds shall be made with minimum gap and 50 percent at maximum gap. b) Welding gap shall be measured after weld alignment (peaking) on both sides of the rail head (or on the running surface), web mid point and both foot tips. The maximum gap is the maximum at any of the above points and minimum the minimum of any of the above points. c) The weld gap for all welds made for Table 3 tests shall be within the specified range. In the case of the welds required for test H in category 1 of Table 3, one weld shall be produced at the minimum gap and one at the maximum. d) The number of each test shall be in accordance with the appropriate parts of Tables 3 and 4. The process supplier shall determine the order of testing. e) Where tests fail to meet the required test criteria as a result of a defect (or defects) in the rail, re-tests shall be made on a one-to-one basis. 6 Re-approval following process changes 6.1 Changes to the following require approval: 6.1.1 Any geometric parameters given in 5.4.2: a) weld collar width (W); b) collar depth (D); c) collar depth (d); d) riser cross-section – in foot; e) riser cross-section – in neutral axis; f) riser configuration – position; g) riser configuration – numbers. A revised drawing shall be submitted. 6.1.2 Crucible system: — Any changes in the chemical nature of the main component of the refractory. 6.1.3 Pre-heating system: — Any change in the equipment or parameters; — any change of pre-heating fuels (oxidising or reducing); — any change in working pressure or pre-heating times outside the ranges originally specified. 6.1.4 Welding gap: Initial approval involves testing a welding process at either end of the ranges specified in 5.4.1, e). SIST EN 16771:2017
EN 16771:2016 (E) 13 If the maximum gap proposed exceeds the maximum covered by the initial approval, testing is required at the new maximum gap. If the minimum gap proposed is less than the minimum
...
SLOVENSKI STANDARD
oSIST prEN 16771:2014
01-oktober-2014
äHOH]QLãNHQDSUDYH,QIUDVWUXNWXUD$OXPLQRWHUPLþQRYDUMHQMHWLUQLFH]åOHERP
Railway applications - Infrastructure - Aluminothermic welding of grooved rails
Bahnanwendungen - Infrastruktur - Aluminiothermisches Schweißen von Rillenschienen
Applications ferroviaires - Infrastructures - Soudage par aluminothermie des rails à gorge
Ta slovenski standard je istoveten z: prEN 16771
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
45.080 7UDþQLFHLQåHOH]QLãNLGHOL Rails and railway
components
oSIST prEN 16771:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 16771:2014
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oSIST prEN 16771:2014
EUROPEAN STANDARD
DRAFT
prEN 16771
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2014
ICS 25.160.10; 93.100
English Version
Railway applications - Infrastructure - Aluminothermic welding of
grooved rails
Applications ferroviaires - Infrastructures - Soudage par Bahnanwendungen - Infrastruktur - Aluminiothermisches
aluminothermie des rails à gorge Schweißen von Rillenschienen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 256.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16771:2014 E
worldwide for CEN national Members.
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oSIST prEN 16771:2014
prEN 16771:2014 (E)
Contents
Page
Foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Information to be supplied by the railway authority . 7
5 Approval procedure . 7
5.1 General . 7
5.2 Process identification . 7
5.3 General requirements . 7
5.4 Documents to be submitted with the request for approval . 8
5.4.1 The process manual . 8
5.4.2 Drawing with the required measurements . 8
5.4.3 Chemical analysis ranges and tolerances . 9
5.5 Initial compliance testing . 9
5.6 Extension of initial compliance testing. 11
5.7 Preparation and allocation of test welds . 11
6 Re-approval following process changes . 12
6.1.2 Crucible system. 12
6.1.3 Tapping system . 12
6.1.4 Pre-heating system . 12
6.1.5 Welding gap . 13
7 Laboratory tests . 15
7.1 Visual surface examination . 15
7.1.1 As cast weld surface . 15
7.1.2 Ground weld surface . 15
7.2 Running surface hardness test . 17
7.3 Slow bend test . 17
7.4 Internal examination . 17
7.4.1 Weld soundness . 17
7.4.2 Fusion zone – Shape and dimension . 20
7.4.3 Microscopic examination . 20
7.4.4 Heat softened zone width . 20
7.5 Chemical analysis . 21
Annex A Annex A (informative) Steps in approval . 23
Annex B (informative) Suggested sequence of laboratory tests . 25
Annex C Annex C (normative) Procedure for FRY etching. 26
Annex D (normative) Procedure for measurement of surface hardness . 28
Annex E Annex E (normative) Procedure for slow bend test . 29
Annex F (normative) Procedure for recording test weld fracture face defects . 31
Annex G (normative) Ultrasonic inspection procedure on aluminothermic welds to be
sectioned . 32
G.1 Principle . 32
G.2 Apparatus . 32
2
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oSIST prEN 16771:2014
prEN 16771:2014 (E)
G.3 Preparation of samples . 32
G.4 Calibration . 32
G.5 Testing . 32
G.6 Reporting . 33
Annex H (normative) Procedure for microscopic examination of the visible heat affected zone
and fusion zone of welds . 34
Annex I (normative) Procedure for measurement of the heat softened zone width. 35
I.1 Measurement of hardness . 35
I.2 Evaluation of hardness data . 35
I.2.1 General . 35
I.2.2 Mean hardness of parent rail . 36
I.2.3 Measurement hardness line . 36
I.2.4 Heat softened zone width measurement. 36
I.2.5 Parent rail hardness variation . 36
3
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oSIST prEN 16771:2014
prEN 16771:2014 (E)
Foreword
This document (prEN 16771:2014) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
4
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oSIST prEN 16771:2014
prEN 16771:2014 (E)
Introduction
This standard defines the approval procedure for aluminothermic welding processes for grooved rail
welding through laboratory tests of welds produced in a workshop. This laboratory approval will provide the
railway authority with sufficient information for tests in the track if required.
5
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oSIST prEN 16771:2014
prEN 16771:2014 (E)
1 Scope
This standard defines the laboratory tests and requirements for approval of an aluminothermic welding
process using welds produced in workshop conditions.
It applies to the joining of new, grooved rails as described in EN 14811 of the same profile and steel grade.
Welding of construction profiles and machined profiles are not covered in this standard.
Compliance with the requirements of this standard does not of itself ensure the suitability of a welding
process for specific conditions of track and traffic.
The standard does not cover welds made between different rail sections, worn rails or different rail grades.
In addition to the definitive requirements this standard also requires the items detailed in Clause 4 to be
documented. For compliance with this standard, it is important that both the definitive requirements and the
documented items be satisfied.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 9712, Non destructive testing – Qualification and certification of NDT personnel (ISO 9712)
EN 14811, Railway applications – Track – Special purpose rail – Grooved and associated construction
EN ISO 6506-1, Metallic Materials – Brinell hardness test – Part 1: Test method (ISO 6506-1)
EN ISO 6507-1, Metallic materials – Vickers hardness test – Part 1: Test method (ISO 6507-1)
EN ISO 7500-1, Metallic materials – Verification of static uniaxial testing machines – Part 1:
Tension/compression testing machines – Verification and calibration of the force-measuring system
(ISO 7500-1)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
term fusion zone
area of the weld which has been in a liquid state and which is revealed by etching sections cut through the
weld
3.2
visible heat-affected zone
areas on either side of the fusion zone within the rail steel microstructure has been visibly modified by the
heat of the welding process as revealed by FRY macro-etching
3.3
heat softened zone
part of the HAZ characterised by a lower hardness
3.4
flashing
flat fin of weld metal located on the rail surface adjacent to the weld collar caused by gaps between the
mould and the rail
6
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oSIST prEN 16771:2014
prEN 16771:2014 (E)
3.5
surface defect
any defect visible on the weld surface after normal finishing operations
3.6
internal defect
any defect that is revealed by sectioning or on a fracture face following bend testing that has not already
been identified as a surface defect
3.7
railway authority
either the railway regulator or the owner of a railway infrastructure or the custodian with a delegated
responsibility for a railway infrastructure
3.8
process supplier
company which provides an approved aluminothermic welding process in accordance with this standard
and which is approved by the railway authority to supply consumables and tools for the execution of
aluminothermic welds
4 Information to be supplied by the railway authority
The following information shall be fully documented by the railway authority. For compliance with the
standard both the definitive requirements specified throughout the standard and the following documented
items shall be satisfied:
a) any limitation on the weld collar geometry affected by riser removal (other than that on the ground rail
head);
b) any limit on the depth of the weld collar’s edge (less than 2 mm) that may remain unfused to the rail
surface;
c) which of the width levels of heat-softened zone is required (7.4.4);
d) any limitations on the type of pre-heating.
5 Approval procedure
5.1 General
An outline of the steps required for compliance to this standard is given in informative Annex A.
5.2 Process identification
The approval shall involve a single process identified by:
a) the process name;
b) A drawing of the pouring system and the casting system;
c) the characteristic geometry of the weld collar and riser configuration as given in 5.4.2 and Figure 1;
d) the process manual in accordance with 5.4.1.
5.3 General requirements
The following requirements shall be met.
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a) the process shall be capable of being carried out on track and at or near trackside or in a workshop;
b) the aluminothermic welding portion shall be packed to avoid the risk of moisture contamination in
prescribed storage conditions. The portion shall be identified by markings on the package;
c) the mould shall be pre-fabricated for the rail profiles to be welded and be identified by markings on the
package;
d) the crucible shall be tapped automatically (automatic tapping) and shall have a device to limit
spattering;
e) pre-heating shall comply with any limitations of the railway authority as specified in clause 4, d);
f) the process shall not damage the rail.
5.4 Documents to be submitted with the request for approval
When applying for approval, the following documents shall be submitted:
5.4.1 The process manual
The supplier shall produce a manual identifying all the consumable materials and equipment used, as well
as the operating method to be followed for all steps of welding. The approval procedure for laboratory tests
will not include means of alignment or finishing operations. The manual shall specify the critical parameters
of the welding process and their safe bounds, and shall include the following:
a) number of people required to carry out the operations;
b) diagram of equipment;
c) portion for each rail grade and profile;
d) rail end preparation requirements;
e) nominal gap shall have a tolerance of ± 2 mm for a gap up to 30 mm and ± 3 mm for gaps above
30 mm and up to 50 mm and ± 5 mm for gaps above 50 mm;
f) preheating details;
g) range of ignition to tap times for the portion;
h) critical process timings;
i) time (or temperature) before trains can pass;
j) safety information.
5.4.2 Drawing with the required measurements
A drawing, as illustrated in Figure 1, which provides the measurements listed below:
a) weld collar width (W1). The development of the weld collar shall be fully dimensioned around the weld;
b) maximum depth of collar at section B-B (D1 and D2);
c) minimum depth of collar at section B-B (d1 and d2);
d) riser cross section at foot;
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e) riser cross section at neutral axis;
f) number of risers;
g) position of risers.
The dimensions W, D and d and cross sectional areas of the risers shall be the nominal dimensions taken
from the drawing of the pattern used to produce the moulds.
Key
1 Figure showing the width of the weld collar around the weld
2
2 Riser cross section on the neutral axis mm
3 25 % of the foot width
2
4 Riser cross section at the foot mm
Figure 1 — Dimensions taken from mould pattern
5.4.3 Chemical analysis ranges and tolerances
The chemical analysis ranges and tolerances according to 7.5.1.
5.5 Initial compliance testing
a) For the purposes of approval the standard rail profiles (see EN 14811) shall be grouped as follows:
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Table 1 —Rail profile groups 1
New names Former names
57R1 Ph 37
59R1 Ri 59-R10, Ri 59
59R2 Ri 59-R13, Ri 59N
60R1 Ri 60-R10, Ri 60
60R2 Ri 60-R13, Ri 60 N
60R3 Ri 210/95+80
62R1 NP4aM
62R2 NP4aS
63R1 Ri 210/95+80a
67R1 Ph 37a
68G1 70 G
Table 2 —Rail profile groups 2
New names Former names
46G1 60 G
51R1 Ri 52-R13, Ri 52
52R1 Ri Ir
53R1 Ri 53-R13, Ri 53
55G1 35 GP
55G2 41 GP
56R1
Ri lc
b) Initial compliance with this standard shall be achieved by undertaking the tests specified in category 1
of Table 3 using not heat treated rail, by using either R200 or R220G1 or R260 grade. Results are
valid for the three grades of all rail profile in either group 1 or group 2. Compliance with all the criteria
specified and with the railway authority’s documented requirements specified in clause 4 shall be
demonstrated. A test sequence is outlined in informative Annex B. A test specimen can be used for
several different tests.
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Table 3 —Testing scheme
Number of tests
Section
Test
a b
reference
Category 1 Category 2
A Hardness test 7.2 6 5
7.1.1
B Surface examination –
6 5
Visual
7.1.2
C Slow Bend Test 7.3 6 3
D Ultrasonic inspection –
7.4.1.1 2 Nil
Annex G
7.4.1 2
E Weld soundness Nil
7.3 (2)
F Fusion Zone
2 Nil
– Shape and Dimensions 7.4.2
G Chemical analysis 7.5 3 3
H Heat softened zone
2 2
– Hardness distribution 7.4.4
I Structure
– Fusion Zone 7.4.3.3 2 1
– Heat affected zone 7.4.3.2 2 1
NOTE ( ) indicates weld soundness evaluation of the fracture face of the slow
bend test specimens.
a
Category 1 Initial tests to be conducted using not heat treated grade on one rail
profile from group 1 or 2 (Table 1 or 2).
b
Category 2 Tests required extending approval for heat treated grades. Tests on one
rail profile cover all profile groups approved in categories 1 or 2.
5.6 Extension of initial compliance testing
Initial compliance can be extended as follows:
The relevant railway authority requirements defined in clause 4 shall be met for each of the items below:
a) to other group of rail profiles listed in Table 1 or 2 [sub-clause 5.5 a)], by doing the tests given in
Table 3 category 1 [sub-clause 5.5 b)] on one profile of the appropriate group. Failure of any test shall
cause non-compliance for the group of rail profiles being tested;
b) to other rail grade by doing the tests given in Table 3 category 2 [sub-clause 5.5 b)]. Failure of any test
shall cause non-compliance for that rail grade. Tests on one rail profile cover all profiles in group 1 or
2.
5.7 Preparation and allocation of test welds
a) Welds required for the tests shall be produced in accordance with the process manual (5.4.1) under
the supervision of the approving authority recognised by the railway authority. Rails to be used for the
production of test welds shall be new rails. Fifty percent of test welds shall be made with minimum gap
and fifty percent at maximum gap.
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b) Welding gap shall be measured after weld alignment (peaking) on both sides of the rail head (or on the
running surface), web mid point and both foot tips. The maximum gap is the maximum at any of the
above points and minimum the minimum of any of the above points.
c) The weld gap for all welds made for Table 3 tests shall be within the specified range. In the case of the
welds required for test H in category 1 of Table 3, one weld shall be produced at the minimum gap and
one at the maximum.
d) The number of each test shall be in accordance with the appropriate parts of Tables 3 and 4. The
process supplier shall determine the order of testing.
e) Where tests fail to meet the required test criteria as a result of a defect (or defects) in the rail, re-tests
shall be made on a one-to-one basis.
6 Re-approval following process changes
6.1 Changes to the following require approval:
6.1.1 Any geometric parameters given in 5.4.2:
a) weld collar width (W);
b) collar depth (D);
c) collar depth (d);
d) riser cross-section – in foot;
e) riser cross-section – in neutral axis;
f) riser configuration – position;
g) riser configuration – numbers.
A revised drawing shall be submitted.
6.1.2 Crucible system
Any changes in the chemical nature of the main component of the refractory.
Internal crucible geometry changes outside the range covered by the tolerances shown on the
suppliers drawing.
6.1.3 Tapping system
Any changes in the geometry of the tapping system body outside the suppliers drawing.
6.1.4 Pre-heating system
Any change in the equipment or parameters;
Any change of pre-heating fuels (oxidising or reducing);
Any change in working pressure or pre-heating times outside the ranges originally specified.
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6.1.5 Welding gap
Initial approval involves testing a welding process at either end of the ranges specified in clause 5.4.1 e).
If the maximum gap proposed exceeds the maximum covered by the initial approval, testing is required at
the new maximum gap. If the minimum gap proposed is less than the minimum covered by the initial
approval, testing is required with new minimum gap.
Measurement of the gap shall be made as defined in section 5.7 b).
6.2 Where the proposed change lies within the range or ranges given in Table 4, the tests shall be
undertaken as detailed in Table 4. The change shall be approved if the acceptance criteria for each of the
required tests are met. In house laboratory facilities shall be approved by the railway authority.
6.3 Changes which fall outside the limits of the range or ranges given in Table 4 shall only be approved if
they meet the requirements for demonstrating initial compliance as given in Table 3.
6.4 In the case of the combination of multiple changes, the number of tests to be undertaken will be the
largest number required in each column of Table 4 for these particular changes. e.g. combining changes to
the pre-heating system and welding gap shall require 6 of test A (not 12), 6 of test C (not 12), etc.
6.5 Re-approval following the process changes detailed in Table 3 shall be made in one profile of
group 1 of Table 1 or group 2 of Table 2 and rail grade R200, R220G1 or R260 and shall cover all profiles
and grades of the existing approval.
6.6 Failure of the relevant tests of Table 4 shall cause non-compliance of the process change.
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Table 4 — Process changes
a b
In house External
Total
Number of tests (Test as defined in Table 2)
number
Test
A C E F G H I
Range or Range or
of welds
modification modification
required
Weld Chemical HAZ
Centreline Slow Fusion
Structure
hardness bend test width
soundness analysis hardness
6.1.1 a) Weld collar width W ± 3 mm ± 10 mm - - 4 4 - - - 4
6.1.1 b) Collar depth (D) ± 2 mm ± 6 mm - - 4 4 - - - 4
6.1.1 c) Collar depth (d) ± 2 mm ± 4 mm - - 4 4 - - - 4
6.1.1 d) Riser X-section – Foot ± 10 % ± 30 % - - 4 4 - - - 4
6.1.1 e) Riser X-section – Neut. Axis ± 10 % ± 40 % - - 4 4 - - - 4
6.1.1 f) Riser config. – Position ± 5 mm ± 10 mm - 6 4 4 - - - 10
6.1.1 g) Riser config. – Numbers - All - 6 4 4 - - - 10
6.1.2 Crucible system - All - 6 - - 3 - - 6
6.1.3 Tapping system - All - 6 - 4 3 - - 10
6.1.4 Pre-heating system - All 6 6 4 4 - 2 - 10
6.1.5 Welding gap - All 6 6 4 4 - 2 - 10
a
In house – Conducted by the process supplier
b
External – Conducted by a laboratory approved by the railway authority
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7 Laboratory tests
7.1 Visual surface examination
7.1.1 As cast weld surface
Following stripping and final grinding the as-cast weld collar surface shall be visually examined for soundness.
For the process to be accepted:
there shall be no cracks with length of 2 mm, or greater. Joints between weld collars and rail and flashing
and rail are not cracks;
there shall be no pores with a dimension greater than 3 mm, nor shall there be more than three pores in
the size range 2 mm to 3 mm per test piece excluding flashing;
slag or sand inclusions shall not exceed the limits set in Table 5. No defect shall intrude into the rail cross
section nor touch the edge of the weld collar/rail intersection.
Table 5 — Maximum dimensions of slag or sand defects
Surface dimension Depth
(max) (max)
(mm) (mm)
10 3
15 2
20 1
7.1.2 Ground weld surface
Two zones with different inspection criteria are defined in accordance with the figures below.
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Key
1: Ground zone
2: Not ground zone
Figure 2 — Definition of ground weld surface
For ground zone:
For isolated and none linear defect, on the external and internal part of the head of the rail:
All defects less than 4 mm with a maximum of 4 defects are allowed
For isolated and none linear defect, on the running head of the rail:
All defects less than 4 mm with a maximum of 5 defects are allowed
For linear and multiple defects, on the external and internal part of the head of the rail:
All defects less than 3 mm with a maximum of 2 defects are allowed
If the distance between two defects is less than 10 mm, the defect is considered as a linear and single defect.
For not ground zone:
For isolated and none linear defect:
All defects less than 6 mm with
...
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