EN 14730-1:2017

SLOVENSKI STANDARD
01-maj-2017
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SIST EN 14730-1:2007+A1:2010
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Railway applications - Track - Aluminothermic welding of rails - Part 1: Approval of
welding processes
Bahnanwendungen - Oberbau - Aluminothermisches Schweißen von Schienen - Teil 1:
Zulassung der Schweißverfahren
Applications ferroviaires - Voie - Soudage des rails par aluminothermie - Partie 1:
Approbation des procédés de soudage
Ta slovenski standard je istoveten z: EN 14730-1:2017
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
45.080 7UDþQLFHLQåHOH]QLãNLGHOL Rails and railway
components
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 14730-1
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2017
EUROPÄISCHE NORM
ICS 25.160.10; 93.100 Supersedes EN 14730-1:2006+A1:2010
English Version
Railway applications - Track - Aluminothermic welding of
rails - Part 1: Approval of welding processes
Applications ferroviaires - Voie - Soudage des rails par Bahnanwendungen - Oberbau - Aluminothermisches
aluminothermie - Partie 1: Approbation des procédés Schweißen von Schienen - Teil 1: Zulassung der
de soudage Schweißverfahren
This European Standard was approved by CEN on 13 August 2016.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14730-1:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Information to be supplied by the railway authority. 8
5 Approval procedure . 8
5.1 General . 8
5.2 Process identification . 8
5.3 General requirements . 9
5.4 Documents to be submitted with the request for approval . 9
5.4.1 The process manual . 9
5.4.2 Drawing with the required measurements . 10
Figure 1 — Dimensions taken from mould pattern . 10
5.4.3 Chemical analysis ranges and tolerances . 11
5.5 Initial compliance testing . 11
Table 1 — Rail profile groups . 11
Table 2 — Testing scheme . 11
5.6 Extension of initial compliance testing . 12
5.7 Preparation and allocation of test welds . 12
6 Re-approval following process changes . 13
6.1 Changes requiring approval . 13
6.1.1 Geometric parameters . 13
6.1.2 Crucible system . 13
6.1.3 Tapping system . 13
6.1.4 Pre-heating system . 13
6.1.5 Portion . 13
6.1.6 Welding gap . 14
6.2 Test requirements for re-approval following process changes . 14
Table 3 process changes . 15
7 Laboratory tests . 17
7.1 Visual surface examination . 17
7.1.1 As-cast weld surface . 17
Table 4 — Maximum dimensions of slag or sand defects . 17
7.1.2 Ground weld surface . 17
7.1.3 Visible heat affected zone. 17
7.2 Running surface hardness test . 17
Table 5 — Ranges for running surface hardness tests. 18
7.3 Slow bend test . 18
7.4 Internal examination . 18
7.4.1 Weld soundness . 18
Figure 2 — Transverse section of head, web and foot of the rail . 19
Figure 3 — Sectioning of Welds . 20
7.4.2 Fusion zone – Shape and dimension . 21
Figure 4 — Shape of fusion zone on the etched longitudinal vertical section . 21
7.4.3 Fusion zone . 21
7.4.4 Heat softened zone width . 22
Table 6 — Ranges of heat softened zone . 22
7.5 Fatigue test . 22
7.6 Chemical analysis . 22
Table 7 — Chemical composition . 23
Annex A (informative) Steps in approval . 24
Annex B (informative) Suggested sequence of laboratory test . 25
Annex C (normative) Procedure for Fry etching . 26
Annex D (informative) Procedure for measurement of surface hardness. 27
Figure D.1 — Location of surface hardness tests . 27
Annex E (normative) Procedure for slow bend test . 28
Figure E.1 — Slow bend test schematic . 28
Annex F (normative) Procedure for recording test weld fracture face defects . 29
Figure F.1 — Rail profile grid . 30
Annex G (normative) Ultrasonic inspection procedure on aluminothermic welds to be
sectioned . 31
G.1 General . 31
G.2 Test equipment. 31
G.3 Preparation of samples . 31
G.4 Adjustment . 31
G.5 Testing . 32
G.6 Reporting . 32
Annex H (normative) Procedure for microscopic examination of the visible heat affected
zone and fusion zone of welds . 33
Figure H.1 — Scheme for taking samples for microscopic examination . 33
Annex I (normative) Procedure for measurement of the heat softened zone width . 34
I.1 Measurement of hardness . 34
Figure I.1 — Longitudinal hardness measurement . 34
I.2 Evaluation of hardness data . 34
I.2.1 General . 34
Figure I.2 — Typical hardness profile . 35
I.2.2 Mean hardness of parent rail . 35
I.2.3 Measurement hardness line . 35
I.2.4 Heat softened zone width measurement . 35
I.2.5 Parent rail hardness variation . 35
Annex J (normative) Fatigue test methods for aluminothermic welds . 36
J.1 General . 36
J.2 Test equipment . 36
Figure J.1 — Fatigue test arrangement . 36
J.3 Calibration procedure . 37
J.4 Fatigue test results . 37
J.4.1 General . 37
J.4.2 Staircase testing method . 37
J.4.2.1 Test pieces . 37
J.4.2.2 Procedure. 37
J.4.2.3 Data analysis . 38
J.4.2.4 Acceptance criteria . 39
J.4.3 Example of the data analysis of a fatigue strength determination by the staircase
method . 39
Table J.1 — Experimental results . 39
J.4.4 Past-the-post testing method . 40
J.4.4.1 Test pieces . 40
J.4.4.2 Procedure. 40
J.4.4.3 Information to be reported . 40
J.4.4.4 Acceptance criterion . 40
Annex K (informative) A–deviations . 41
Bibliography . 42

European foreword
This document (EN 14730-1:2017) 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 September 2017, and conflicting national standards
shall be withdrawn at the latest by September 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.
This document supersedes EN 14730-1:2006+A1:2010.
The European Standard EN 14730 “Railway applications – Track – Aluminothermic welding of rails” is
composed of two parts:
— Part 1: Approval of welding processes
— Part 2: Qualification of aluminothermic welders, approval of contractors and acceptance of welds
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
This standard defines the approval procedure for aluminothermic welding processes for 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.
1 Scope
This European 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 Vignole rails as described in EN 13674-1 of the same profile and steel
grade.
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, differently worn rails and
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 13674-1, Railway applications - Track - Rail - Part 1: Vignole railway rails 46 kg/m and above
EN ISO 6506-1, Metallic materials - Brinell hardness test - Part 1: Test method (ISO 6506-1:2014)
EN ISO 6507-1, Metallic materials - Vickers hardness test - Part 1: Test method (ISO 6507-1:2005)
EN ISO 9712, Non-destructive testing - Qualification and certification of NDT personnel (ISO 9712:2012)
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
areas on either side of the fusion zone within which 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 Heat Affected Zone (HAZ) characterised by a lower hardness
3.4
weld collar
external profile of the as-cast weld metal that remains after removal of the moulds
3.5
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
3.6
surface defect
any defect visible on the weld surface after normal finishing operations
3.7
internal defect
any defect that is revealed by sectioning or on a fracture face following bend or fatigue testing that has
not already been identified as a surface defect
3.8
stress range
stress range for the fatigue test is the maximum stress minus minimum stress
3.9
railway authority
either the railway regulator or the owner of a railway infrastructure or the custodian with a delegated
responsibility for a railway infrastructure
3.10
process supplier
company which provides an 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) Pre-heating shall comply with any limitations of the railway authority.
b) Which of the width levels of heat-softened zone is required (7.4.4).
c) The fatigue test, if required by the railway authority, either past the post or staircase method, shall
be carried out in accordance to Annex J and to the requirements as specified in 7.5.
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.
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.
— The process shall be capable of being carried out on track where the maximum cant can be 180 mm.
It shall be capable of being carried out in track, at or near trackside or in a workshop.
— 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.
— The mould shall be pre-fabricated for the rail profiles to be welded and be identified by markings
on the package.
— The crucible shall be tapped automatically (automatic tapping) and shall have a device to limit
spattering.
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 shall 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 ≤ 30 mm
• ± 3 mm for gaps > 30 mm and ≤ to 50 mm
• ± 5 mm for gaps > 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;
e) riser cross section at neutral axis;
f) number of risers;
g) position of risers.
The dimensions W1, D1 and d1 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 (W1) around the weld
2 Riser cross section on the neutral axis mm
3 25 % of the foot width
4 Riser cross section at the foot mm
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 7.6.
5.5 Initial compliance testing
a) For the purposes of approval the standard rail profiles (see EN 13674-1) shall be grouped as
follows:
Table 1 — Rail profile groups
Group Rail profiles
1 60E1, 60E2
2 54E1, 54E2, 54E3, 54E4, 54E5, 55E1, 56E1
3 46E1, 46E2, 46E3, 46E4, 49E1, 49E2, 49E3, 49E5,
50E1, 50E2, 50E3, 50E4, 50E5, 50E6, 52E1
b) Initial compliance with the present standard shall be achieved by undertaking the tests specified in
category 1 of Table 2 using grade R260 rail of one profile in group 1 of Table 1. 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.
Table 2 — Testing scheme
Number of tests
Category Category
c
Category 3
Section
a b
1 2
Test
reference
R260 R260 R200/R220/R260Mn/R350HT/
only only
R320Cr/R350LHT/R370CrHT/R400HT
A Hardness Test 7.2 6 Nil 6
B Surface
7.1.1
Examination – All All All
7.1.2
Visual
C Visible Heat
7.1.3 2 2 2
Affected Zone
D Slow Bend
7.3 6 2 4
Test
E Ultrasonic
Inspection – 7.4.1 5 2 Nil
Annex G
F Fatigue Test
7.5 n* Nil Nil
(Optional)
G Fusion Zone
7.3
(6) (2) (4)
– Weld
7.4.1
5 2 Nil
Soundness
(n*) Nil Nil
7.5
H Fusion Zone
7.4.2 5 2 Nil
– Shape and
Dimensions
I Chemical
7.6 3 Nil 2
Analysis
J Heat Softened
Zone
7.4.4 2 2 2
– Hardness
Distribution
K Structure
7.4.3 1 Nil 1
– Visible Heat
Affected Zone
7.4.4 1 Nil 1
– Fusion Zone
Minimum
number of  11 + n* 4 6
welds
NOTE 1 n* indicates the number of welds required for one staircase or past the post evaluation. Typically, 10 test
pieces will be required for a staircase and 3 for a past the post evaluation.
NOTE 2 () indicates weld soundness evaluation of the fracture face of the slow bend test or fatigue specimens.
a
Category 1: initial tests to be conducted using R260 grade rail and one profile from rail profile Group 1 (Table 1).
Tests carried out on one profile, approves the other profile of that group
b
Category 2: tests to be carried out on one profile from each of the remaining rail profile groups (R260)in order to
extend approval to that group
c
Category 3: For each other rail grade the tests specified in category 3 shall be conducted on one profile of group 1 or
group 2 in order to extend the approval to all profile groups already covered by category 2 tests.
5.6 Extension of initial compliance testing
Initial compliance can be extended as follows.
The relevant railway authority requirements defined in Clause 4 a) to c) shall be met for each of the
items below:
a) For other groups of rail profiles in Table 1, the tests given in category 2 of Table 2 shall be
conducted on only one profile from each of the appropriate groups to approve the whole group.
b) For other rail grades by the tests in category 3 of Table 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 categories 1 and 2.
5.7 Preparation and allocation of test welds
a) 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.
b) The weld gap for all welds made for Table 2 tests shall be within the specified range. In the case of
the welds required for test H in category 1 of Table 2, three welds shall be produced at the
minimum gap and two at the maximum, and for category 2 of Table 2, one weld at the maximum
gap and one weld at the minimum gap.
c) The number of each test shall be in accordance with the appropriate parts of Tables 2 and 3. The
process supplier shall determine the order of testing.
d) 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 requiring approval
6.1.1 Geometric parameters
— 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 Tapping system
— Any changes in the chemical nature of the main component of the refractory of the tapping system
body;
— Any changes in the geometry of the tapping system body as specified in the original drawing of the
supplier.
6.1.4 Pre-heating system
— Any change in the equipment or critical parameters;
— Any change of pre-heating fuels (oxidising or reducing);
— Any change in working pressure or pre-heating times outside the ranges originally specified.
6.1.5 Portion
— Changes in the weight outside of the production tolerances and changes in the ranges of elements
specified by the process supplier (see Annex A).
6.1.6 Welding gap
Initial approval involves testing a welding process at either end of the ranges specified in 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 5.7 b).
6.2 Test requirements for re-approval following process changes
a) Where the proposed change lies within the range or ranges given in Table 3, the tests shall be
undertaken as detailed in Table 3. 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.
b) Changes which fall outside the limits of the range or ranges given in Table 3 (6.1.1 a) to 6.1.1 f))
shall only be approved if they meet the requirements for demonstrating initial compliance as given
in Table 2.
c) 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 3 for these particular changes. e.g. combining
changes to the pre-heating system and welding gap shall require 6 of test A (not 12), 1 of test C, etc.
d) Re-approval following the process changes detailed in Table 3 shall be made in one profile of
group 1 of Table 1 and rail grade R260 and shall be valid for all profile groups and grades of the
existing approval.
e) Failure of the relevant tests of Table 3 shall cause non-compliance of the process change.
Table 3 process changes
In
b
house External
a
Total
Number of tests (Test as defined in Table 2)
number of
Test
welds
A C D E F G H I J
required
Slow Ultra-
Visible HAZ
Centreline Fatigue Weld Fusion Chemical
bend sonic
hardness test soundness width analysis
HAZ hardness
test test
6.1.1 a)
Weld collar ±3mm ±10mm - - - 4 - 4 4 - - 4
width W
6.1.1 b)
Collar ±2mm ±6mm - - - 4 - 4 4 - - 4
depth (D)
6.1.1 c)
c c
Collar ±2mm ±4mm - - - 4 n 4 4 - - 4 + n
depth (d)
6.1.1 d)
Riser
cross- ±10 % ±30 % - - - 4 - 4 4 - - 4
section –
Foot
6.1.1 e)
Riser
cross- ±10 % ±40 % - - - 4 - 4 4 - - 4
section –
Neut. axis
Range or
modification
Range or
modification
6.1.1 f)
Riser
±5mm ±10mm - - 6 - - 6 4 - - 10
config. –
Position
6.1.1 g)
Riser
- All - - 6 - - 6 4 - - 10
config. –
Numbers
6.1.2
Crucible - All - - 6 - - 6 - 3 - 6
system
6.1.3
Tapping - All - - 6 - - 6 4 3 - 10
system
6.1.4 Pre-
heating - All 6 1 6 - - 6 4 - 2 10
system
6.1.6
Welding - All 6 1 6 - - 6 4 - 2 10
gap
a
In house – Conducted by the process supplier
b
External – Conducted by a test house approved by the railway authority
c
n: One staircase or past the post evaluation. Typically, 10 test pieces will be required for a staircase and 3 for a past the post evaluation
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 4. No defect shall intrude into the rail
cross section nor touch the edge of the weld collar/rail intersection;
Table 4 — Maximum dimensions of slag or sand defects
Surface dimension Depth
[mm] [mm]
(max) (max)
10 3
15 2
20 1
— the condition of the surface left by riser removal (other than that on the ground rail head) shall
conform with the requirements specified in the information supplied by the railway authority.
7.1.2 Ground weld surface
Both side of the ground rail head shall comply with the following:
— There shall be no defects (cracks, pores, slag, sand inclusions, metal beads) with a dimension
greater than 1 mm.
7.1.3 Visible heat affected zone
Following Fry etching in accordance with Annex C the visible heat affected zones on each side of the
weld shall be measured on the rail running surface centre line. The visible heat affected zone shall be
symmetrical about the longitudinal axis of the rail and transverse axis of the weld.
7.2 Running surface hardness test
Measurements shall be made in accordance with Annex D. These shall be carried out on the flat ground
surface (Figure D.1) before final profile grinding takes place.
The average of the three hardness measurements made on each weld shall fall within the range given in
Table 5 for the appropriate parent rail grade.
Table 5 — Ranges for running surface hardness tests
Hardness range
Rail grade
HBW
Rail running surface on the
Weld centre-line
unaffected parent rail
R200 200 to 240 230 ± 20
R220 220 to 260 250 ± 20
R260 260 to 300 280 ± 20
R260 260 to 300 300 ± 20
R260Mn 260 to 300 280 ± 20
R320Cr 320 to 360 330 ± 20
R350HT 350 to 390 350 ± 20
R350LHT 350 to 390 350 ± 20
R370CrHT 370 to 410 370 ± 30
a
R400HT 400 to 440 390 ± 30
a
A different hardness range is permitted for R400HT rail grade with the agreement of the appropriate
railway authority.
NOTE The centre-line hardness of the welds for the chromium alloyed and for the heat-treated grades is
established below the hardness values of the rail running surface to ensure a fully pearlitic structure. The
hardness profile along the rail crown centre-line of welds varies with the level of alloying element additions, with
higher alloyed welds showing a relatively higher hardness at the weld edges. Therefore to achieve the correct
average hardness, a lower centre-line hardness is required.
7.3 Slow bend test
Details of the slow bend test procedure are given in Annex E.
The minimum fracture load (kN), rounded to the nearest 5 kN is defined by the formula F = 0,0032 S
(equivalent to a minimum tensile bending strength of 800 MPa), where S (mm ) is the section modulus
for the base of the rail, given in EN 13674-1.
For R200 grade rail, a minimum tensile bending strength of 700 MPa is required. The formula
F = 0,0028 S shall be used for this purpose.
The formula F = 0,003 S shall be used for R320Cr, R370CrHT and R400HT rail grades.
The fracture face shall be subject to the soundness examination in accordance with 7.4.1 and a record
made in accordance with Annex F.
7.4 Internal examination
7.4.1 Weld soundness
Welds for ultrasonic inspection (test E in Table 2 and Table 3) shall be cut so that the head, web and
foot of the rail containing the weld (see Figure 2) can be examined ultrasonically in accordance with
Annex G. The positions of any apparent defects found by ultrasonic testing shall be recorded so that
they may be revealed by sectioning. Cuts shall be positioned at least 5 mm from any apparent defects
located by the ultrasonic testing method specified in Annex G. For each defect, the size shall be
determined by progressively grinding or machining and measuring until the maximum dimension is
found.
Key
1 Head
2 Profile of rail
3 Profile of weld
4 Web
5 Foot
Figure 2 — Transverse section of head, web and foot of the rail
The rails containing the welds shall then be sectioned to give:
— longitudinal vertical section on the symmetry plane (cut 1 in Figure 3);
— longitudinal vertical sections in the rail foot (cuts 2 in Figure 3).
Dimension in millimetres
Key
1 Longitudinal vertical section on centre line
2 Longitudinal vertical section of foot tip
Figure 3 — Sectioning of Welds
Visual examination of the cut sections (polished to 220 grit) shall show no evidence of lack of fusion
between the rail and fusion face.
The weld collar's edge is permitted to be unfused to the rail surface for a maximum of 2 mm from the
edge of the collar unless a lesser figure is specified in the information supplied by the railway authority
(see 4b).
The maximum dimension of any pores, slag inclusions, sand inclusions or metal beads shall be
recorded. If multiple defects are revealed, they shall be counted and measured as a single defect if they
are less than 1 mm apart:
— no more than one defect with maximum dimension greater than 2 mm in the region of the head
above the line A-A on Figure 2 shall be permitted.
NOTE 1 The information on weld soundness collected by the requirements of this subclause is used for
reference in the appropriate tests of Clause 6 required for process changes.
NOTE 2 Areas containing micro-porosity or inter-dendritic shrinkage are not counted as single defects and
therefore are not taken into consideration.
Fracture faces revealed by the slow bend test specified in 7.3 and each of the fatigue test pieces
specified in 7.5 shall be examined visually and a record made, in accordance with Annex F, of the
maximum dimensions of any pores, slag inclusions, sand inclusions or metal beads.
Per population of test welds in test G in Table 2 and Table 3:
— no more than one volumetric defect with maximum dimension greater than 2 mm in the region of
the head above the line A-A on Figure 2 shall be permitted.
7.4.2 Fusion zone – Shape and dimension
Following Fry etching in accordance with Annex C, measurement of the fusion zone shall be made on
the cuts illustrated in Figure 4.
The minimum distance X (Figure 4) between the parent rail ends before welding and the fusion line
shall be equal to or greater than 3 mm.
Measurement of X shall be made using datum marks to locate the original position of the rail ends.

Key
* Datum marks
1 Fusion line
2 Rail ends before welding
3 Rail head
4 Rail foot
Figure 4 — Shape of fusio
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