SIST-TP CEN ISO/TR 17641-3:2005

Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc welding processes - Part 3: Externally loaded tests (ISO/TR 17641-3:2005)

ISO/TR 17641-3:2005 outlines the test methods and procedures for carrying out externally loaded tests to assess susceptibility to hot cracking.
The following tests are described:
Hot tensile testsVarestraint and Transvarestraint testFlat tensile test.
The above tests can provide information about the hot cracking sensitivity of parent materials, weld metals and weldments. Assessment is based upon the measurement of the "brittle temperature range" (BTR) where hot cracks occur.
This document applies primarily to austenitic stainless steels, nickel-, nickel-base and nickel-copper alloys, weldments and welding consumables. However, the principles can be extended to other materials such as aluminium alloys and high-strength steels.

Zerstörende Prüfung von Schweißverbindungen an metallischen Werkstoffen - Heißrissprüfungen für Schweißungen - Lichtbogenschweißprozesse - Teil 3: Fremdbeanspruchte Prüfungen (ISO/TR 17641-3:2005)

Diese Norm legt die Versuchsdurchführung für fremdbeanspruchte Heißrißprüfungen fest für: - Heißzugversuch; - Varestraint-/Transvarestraint-Versuch; - Flachzugversuch zwecks Ermittlung von Informationen über die Heißrißempfindlichkeit von Schweißzusätzen und Grundwerkstoffen beim Schweißen.

Essais destructifs des soudures sur matériaux métalliques - Essais de fissuration a chaud des assemblages soudés - Procédés de soudage a l'arc - Partie 3 : Essais sur éprouvette soumise a une charge extérieure (ISO/TR 17641-3:2005)

L'ISO/TR 17641-3:2005 souligne les méthodes et modes opératoires d'essais de fissuration à chaud avec charge extérieure.
Les essais suivants sont décrits: essais de traction à chaud; essais Varestraint et Transvarestraint; essai de traction sur éprouvette plate.
Les essais ci-dessus peuvent donner des informations sur la sensibilité à la fissuration à chaud des matériaux de base, du métal fondu et des soudures. L'évaluation est basée sur la mesure d'un «domaine de température de fragilité» (BTR) dans lequel la fissuration à chaud se produit.
L'ISO/TR 17641-3:2005 s'applique essentiellement aux aciers inoxydables austénitiques au nickel, aux alliages à base de nickel, aux alliages en nickel-cuivre, ainsi qu'aux produits consommables correspondants. Cependant, les principes peuvent également servir pour d'autres matériaux, par exemple l'aluminium et ses alliages, ou les aciers à haute résistance, par accord préalable entre les parties contractantes.

Porušitveni preskusi zvarov na kovinskih materialih – Preskusi na pokanje v vročem za zvarne spoje – Obločni načini varjenja – 3. del: Preskus na obremenjenem preskušancu (ISO/TR 17641-3:2005)

General Information

• Status: Published
• Publication Date: 30-Apr-2005
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: VAR - Welding
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-May-2005
• Due Date: 01-May-2005
• Completion Date: 01-May-2005
• Directive: 97/23/EC - Directive 97/23/EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the laws of the Member States concerning pressure equipment
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Ref Project: CEN ISO/TR 17641-3:2005 - Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc welding processes - Part 3: Externally loaded tests (ISO/TR 17641-3:2005)

Relations

• Parent: SIST EN ISO 17641-2:2005 - Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc welding processes - Part 2: Self-restraint tests (ISO 17641-2:2005)
• Effective Date: 22-Dec-2008
• Parent: SIST EN ISO 17641-1:2004 - Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc welding processes - Part 1: General (ISO 17641-1:2004)
• Effective Date: 22-Dec-2008

Overview

CEN ISO/TR 17641-3:2005 - "Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc welding processes - Part 3: Externally loaded tests" (ISO/TR 17641-3:2005) defines methods and procedures for externally loaded laboratory tests used to assess hot cracking susceptibility in welds and weldments. The report focuses on arc welding processes and gives practical test descriptions (hot tensile, Varestraint/Transvarestraint and flat tensile/PVR tests), assessment criteria and specimen requirements. It is primarily aimed at austenitic stainless steels, nickel and nickel‑base alloys and nickel‑copper alloys, with principles extendable to aluminium alloys and high‑strength steels by agreement.

Key Topics

• Externally loaded hot cracking tests: These tests impose controlled strain/strain rates during the brittle temperature range (BTR) to reproduce aspects of welding solidification, liquation and ductility‑dip cracking.
• Tests described:
  • Hot tensile test - simulates welding thermal cycles using cylindrical specimens; Procedure A for solidification cracking (130 mm × 10 mm) and Procedure B for liquation/NST determination (110 mm × 6 mm).
  • Varestraint and Transvarestraint tests - apply bending/strain to a heated weld or TIG melt run to provoke solidification or liquation cracks; useful for weld metal and HAZ assessment.
  • Flat tensile / Programmable Deformation Cracking (PVR) test - measures critical strain (Vcrit) for first hot crack; suited to multipass weldments and welding procedure evaluation.
• Assessment metrics: Brittle Temperature Range (BTR), Nil Strength Temperature (NST), Ductility Recovery Temperature (DRT), critical strain (Vcrit), total crack length (Ltot) and related ratios.
• Test conditions and instrumentation: use of protective Argon atmosphere (oxygen ≤ 0.1 %) to limit oxidation, thermocouple measurement (Pt‑PtRh), controlled heating/cooling rates and defined loading rigs.
• Limitations: Tests provide quantitative ranking and reproducible within a laboratory, but do not exactly reproduce all field welding conditions; inter‑laboratory reproducibility can vary.

Applications and Users

• Used for material selection and qualification, weld metal and welding consumable evaluation, development and qualification of welding procedures, failure investigation and R&D on weldability.
• Typical users: welding engineers, materials scientists, quality control and testing laboratories, fabricators in petrochemical, power generation, aerospace and shipbuilding sectors, and standards bodies.

Related Standards

• EN ISO 17641-1:2004 - Destructive tests on welds - Hot cracking tests for weldments - Part 1: General (normative reference).
• Other parts of the ISO/TR 17641 series (general guidance and complementary test methods) are relevant when designing a full hot‑cracking assessment program.

Keywords: hot cracking tests, Varestraint, Transvarestraint, hot tensile test, flat tensile test, brittle temperature range (BTR), NST, weldability, arc welding processes.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2005
3RUXãLWYHQLSUHVNXVL]YDURYQDNRYLQVNLKPDWHULDOLK±3UHVNXVLQDSRNDQMHY
YURþHP]D]YDUQHVSRMH±2EORþQLQDþLQLYDUMHQMD±GHO3UHVNXVQD
REUHPHQMHQHPSUHVNXãDQFX,6275
Destructive tests on welds in metallic materials - Hot cracking tests for weldments - Arc
welding processes - Part 3: Externally loaded tests (ISO/TR 17641-3:2005)
Zerstörende Prüfung von Schweißverbindungen an metallischen Werkstoffen -
Heißrissprüfungen für Schweißungen - Lichtbogenschweißprozesse - Teil 3:
Fremdbeanspruchte Prüfungen (ISO/TR 17641-3:2005)
Essais destructifs des soudures sur matériaux métalliques - Essais de fissuration a
chaud des assemblages soudés - Procédés de soudage a l'arc - Partie 3 : Essais sur
éprouvette soumise a une charge extérieure (ISO/TR 17641-3:2005)
Ta slovenski standard je istoveten z: CEN ISO/TR 17641-3:2005
ICS:
25.160.40 Varjeni spoji in vari Welded joints
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN ISO/TR 17641-3
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
March 2005
ICS 25.160.40
English version
Destructive tests on welds in metallic materials - Hot cracking
tests for weldments - Arc welding processes - Part 3: Externally
loaded tests (ISO/TR 17641-3:2005)
Essais destructifs des soudures sur matériaux métalliques - Zerstörende Prüfung von Schweißverbindungen an
Essais de fissuration à chaud des assemblages soudés - metallischen Werkstoffen - Heißrissprüfungen für
Procédés de soudage à l'arc - Partie 3 : Essais sur Schweißungen - Lichtbogenschweißprozesse - Teil 3:
éprouvette soumise à une charge extérieure (ISO/TR Fremdbeanspruchte Prüfungen (ISO/TR 17641-3:2005)
17641-3:2005)
This Technical Report was approved by CEN on 20 March 2004. It has been drawn up by the Technical Committee CEN/TC 121.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN ISO/TR 17641-3:2005: E
worldwide for CEN national Members.

Contents page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Symbols, designations and units.4
5 Principle.5
6 Description of the tests.7
6.1 Hot tensile test .7
6.1.1 General.7
6.1.2 Specimen size .7
6.1.3 Protective atmosphere .8
6.1.4 Test procedure.8
6.1.5 Test results.8
6.2 Principles of the Varestraint and Transvarestraint tests.9
6.2.1 General principles.9
6.2.2 Specimen size .12
6.2.3 Test procedure.12
6.2.4 Test results.12
6.3 Flat tensile test.14
6.3.1 General.14
6.3.2 Specimen size .14
6.3.3 Test procedure.15
6.3.4 Test results.16
7 Test reports .17

Figures
Figure 1 — Specimen dimensions for the hot tensile test .7
Figure 2 — Results presentation .9
Figure 3 — Principle of Varestraint (up) /Transvarestraint tests (down) .11
Figure 4 — Typical presentation of results for The Varestraint and Transvarestraint tests .13
Figure 5 — Programmable Deformation Cracking Test (PVR-Test) — Test piece dimension .15
Figure 6 — Test procedure of Programmable Deformation Cracking Test (PVR-Test).16
Tables
Table 1 — Designation and symbols.5
Table 2 — Hot cracking tests, types of cracking and applications .6

Foreword
This document (CEN ISO/TR 17641-3:2005) has been prepared by Technical Committee CEN/TC 121
“Welding”, the secretariat of which is held by DIN, in collaboration with Technical Committee ISO/TC 44
“Welding and allied processes”.

1 Scope
This document outlines the test methods and procedures for carrying out externally loaded tests to assess
susceptibility to hot cracking.
The following tests are described:
 Hot tensile tests
 Varestraint and Transvarestraint test
 Flat tensile test.
The above tests can provide information about the hot cracking sensitivity of parent materials, weld metals
and weldments. Assessment is based upon the measurement of the "brittle temperature range" (BTR) where
hot cracks occur.
This document applies primarily to austenitic stainless steels, nickel, nickel base and nickel copper alloys,
weldments and welding consumables. However, the principles can be extended to other materials such as
aluminium alloys and high strength steels by agreement between contracting parties.
2 Normative references
The following referenced document is 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 ISO 17641-1:2004, Destructive tests on welds in metallic materials — Hot cracking tests for weldments –
Arc welding processes — Part 1: General (ISO 17641-1:2004)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 17641-1:2004 apply.
4 Symbols, designations and units
For the purposes of this document, the symbols and units given in Table 1 apply.
Table 1 — Designation and symbols
Symbol Designation Unit
Hot tensile test
BTR Brittle temperature range, i.e. difference between NST and DTR (see Figure 2) °C
DRR %
Ductility recovery rate, difference (2—3)/(1—3) × 100 (see Figure 2)
DRT Ductility recovery temperature, i.e. temperature at 5% reduction in area measured °C
during "on cooling" tensile test
NDR Nil ductility temperature range, distance (4—6 see Figure 2) °C
NST Nil strength temperature, i.e. peak temperature of the test (See Figure 2, Point 6) °C
RDR -
Ratio of ductility recovery, area (2—3—4)/area (1—3—5) × 100 (See Figure 2)
R Ultimate tensile strength MPa
m
Z Reduction in area %
T Solidus temperature (See Figure 2, Point 7) °C
s
Varestraint- and Transvarestraint test
L Total length of all detected hot cracks mm
tot
I Specimen length mm
R Radius of the former mm
t Specimen thickness mm
w Specimen width mm
Flat tensile test
S Specimen strain %
s
S Strain rate mm/s
v
V Critical strain to form the first hot crack mm/s
crit
W Welding speed cm/min
s
5 Principle
Externally loaded hot cracking tests may be used to provide quantitative information on solidification, liquation
and ductility dip cracking in accordance with Table 2. They are suitable for assessing the susceptibility to hot
cracking of parent materials, weldments and weld metals. However it should be recognised that the exact
mechanisms of the various forms of hot cracking are not fully understood. The different externally loaded tests
described in this document use different criteria for the assessment of susceptibility to hot cracking. None of
the tests reproduce exactly the conditions of temperature, cooling rate, restraint and externally applied strains,
which occur in a wide range of fabrications where hot cracking may be considered to be a potential problem.
Although work continues to address these issues, the tests in their presently developed form can only be used
to rank materials, welding consumables and welding conditions. The results can then be compared with
databases of relevant experience to make judgements as to potential suitability. For this reason it is not
possible to state that any particular test is the most appropriate for any specific requirement. The user of the
test shall decide on the basis of past experience, or on preliminary experiments, which is the most appropriate
test for the required application.
Four types of hot cracking test are described and their relevance to the various forms of hot cracking, and
their possible range of application, are summarised in Table 2.
All the hot cracking tests described depend on the imposition of an external load on the specimen using
suitable test equipment.
This external loading can produce a measurable strain and strain rate on the specimen during the brittle
temperature range (BTR) and can therefore reproduce certain aspects of the welding process. The results
produced from this test are quantitative and are generally reproducible for the same test using a defined
testing procedure and similar equipment.
Unfortunately, equipment and testing procedures are not standardised between different laboratories, and
absolute reproducibility between laboratories is limited. Repeatability of results within a single laboratory using
consistent procedures and the same equipment is generally good.
When parent materials are to be tested, the test specimen is heated either with a TIG melt run in the case of
the Varestraint and flat tensile test or by resistance heating in the hot tensile test. In both cases a HAZ is
formed which is subjected to straining and hence assessment of susceptibility to cracking.
When weld metal is to be tested, a weld deposit is made by the appropriate arc welding process and in the
cases of the Varestraint and flat tensile test, is subjected to straining as the weld solidifies. Any cracking,
which occurs, forms the basis of the assessment. For the hot tensile test the specimen is extracted from a
multipass welded joint and assessment is based on measured mechanical properties using the appropriate
procedure, see 6.1.1
Multipass welds can also be assessed using the Varestaint and flat tensile test, but for these tests, samples
with multipass deposits have to be prepared and the weld metal is then reheated using a similar TIG melt run
to that utilised in parent material tests.
Table 2 — Hot cracking tests, types of cracking and applications
Type of test Type of cracking Results Applications
Solidification L BTR Parent material, selection and approval.
tot
Varestraint
Liquation L Weld metal, selection and approval.
tot
Welding procedures
Ductility Dip L
tot
Weld metal selection
Transvarestraint Solidification L
tot
Welding procedures
Solidification Vcrit Material selection,
Flat tensile type Multipass weldments
Liquation V
crit
(PVR test)
Welding procedures
V
crit
Ductility Dip
Material combinations
Hot tensile test Solidification BTR
TM
Material selection and approval
(Gleeble )
Liquation BTR
Although it is possible for more than one form of hot cracking to be present in a given test piece it should be
noted that the formation of one type of cracking e.g. solidification, may relieve the test strain on the specimen
to such an extent that other forms of cracking do not occur. Therefore the lack of a particular form of cracking
in the testpiece, does not mean that there is no risk of that type of cracking occurring in practice.
The Transvarestraint test was primarily designed to assess weld metal solidification cracking by applying
strains transverse to the length of the weld. It is possible that other types of hot cracking form and if these do
occur, they should be noted on the test report.

6 Description of the tests
6.1 Hot tensile test
6.1.1 General
The hot tensile test determines the hot cracking susceptibility of a material in a simulated welding thermal
cycle using a cylindrical shaped tensile specimen. The specimen can be abruptly broken at any convenient
moment in the welding thermal cycle. For the study of hot cracking where it is necessary to simulate fusion
welding thermal heating, a specimen shall be
...