1、PUBLISHED DOCUMENT PD 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 ICS 25.160.40 PD CEN ISO/TR 17641-3:2005 This Published Document was published under the authority of the Standards Po
2、licy and Strategy Committee on 4 May 2005 BSI 4 May 2005 ISBN 0 580 45849 0 National foreword This Published Document reproduces verbatim ISO/TR 17641-3:2005. The UK participation in its preparation was entrusted to Technical Committee WEE/2, Welding tests, which has the responsibility to: A list of
3、 organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondenc
4、e Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. aid enquirers to understand the text; present to the
5、 responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside fro
6、nt cover, the CEN ISO/TR title page, pages 2 to 17 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsTECHNICALREPORT RAPPORTTECHNIQUE TECHNISCHERBERICHT CENISO/TR176413 March200
7、5 ICS25.160.40 Englishversion DestructivetestsonweldsinmetallicmaterialsHotcracking testsforweldmentsArcweldingprocessesPart3:Externally loadedtests(ISO/TR176413:2005) Essaisdestructifsdessouduressurmatriauxmtalliques Essaisdefissurationchauddesassemblagessouds ProcdsdesoudagelarcPartie3:Essaissur p
8、rouvettesoumiseunechargeextrieure(ISO/TR 176413:2005) ZerstrendePrfungvonSchweiverbindungenan metallischenWerkstoffenHeirissprfungenfr SchweiungenLichtbogenschweiprozesseTeil3: FremdbeanspruchtePrfungen(ISO/TR176413:2005) ThisTechnicalReportwasapprovedbyCENon20March2004.IthasbeendrawnupbytheTechnica
9、lCommitteeCEN/TC121. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKi
10、ngdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2005CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.CENISO/TR176413:2005:EI NECS/OTR -14671:302( 50E) 2 C
11、ontents page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Symbols, designations and units.4 5 Principle5 6 Description of the tests.7 6.1 Hot tensile test .7 6.1.1 General7 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.
12、2 Principles of the Varestraint and Transvarestraint tests.9 6.2.1 General principles9 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 General14 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
13、 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-Te
14、st) 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 2egaP 5002:314671RT/OSIECPage2 CENISO/TR176413:2005I NECS/OTR -14671:302( 50E) 3 Fore
15、word 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”. 3egaP 5002:314671RT/OSIECPage3 CENISO/TR176413:2005I NECS/OTR -1467
16、1:302( 50E) 4 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 in
17、formation 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
18、 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 doc
19、ument. 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:
20、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. 4egaP 5002:314671RT/OSIECPage4 CENISO
21、/TR176413:2005I NECS/OTR -14671:302( 50E) 5 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 (23)/(13) 100 (see Figure 2) % DRT Ductility recovery tempe
22、rature, i.e. temperature at 5% reduction in area measured during “on cooling“ tensile test C NDR Nil ductility temperature range, distance (46 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 (234)/area (1
23、35) 100 (See Figure 2) - R m Ultimate tensile strength MPa Z Reduction in area % T s Solidus temperature (See Figure 2, Point 7) C Varestraint- and Transvarestraint test L tot Total length of all detected hot cracks mm I Specimen length mm R Radius of the former mm t Specimen thickness mm w Specimen
24、 width mm Flat tensile test S s Specimen strain % S v Strain rate mm/s V crit Critical strain to form the first hot crack mm/s W s Welding speed cm/min 5 Principle Externally loaded hot cracking tests may be used to provide quantitative information on solidification, liquation and ductility dip crac
25、king 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
26、 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
27、 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 judgem
28、ents 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 re
29、quired 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 suit
30、able test equipment. 5egaP 5002:314671RT/OSIECPage5 CENISO/TR176413:2005I NECS/OTR -14671:302( 50E) 6 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. T
31、he 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 labo
32、ratories 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 res
33、istance 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 tensi
34、le 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.
35、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
36、of cracking and applications Type of test Type of cracking Results Applications Solidification L tot BTR Liquation L tot Varestraint Ductility Dip L tot Parent material, selection and approval. Weld metal, selection and approval. Welding procedures Transvarestraint Solidification L tot Weld metal se
37、lection Welding procedures Solidification V crit Liquation V crit Flat tensile type (PVR test) Ductility Dip V crit Material selection, Multipass weldments Welding procedures Material combinations Solidification BTR Hot tensile test (Gleeble TM ) Liquation BTR Material selection and approval Althoug
38、h 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 o
39、f 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
40、 that other types of hot cracking form and if these do occur, they should be noted on the test report. 6egaP 5002:314671RT/OSIECPage6 CENISO/TR176413:2005I NECS/OTR -14671:302( 50E) 7 6 Description of the tests 6.1 Hot tensile test 6.1.1 General The hot tensile test determines the hot cracking susce
41、ptibility 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 speci
42、men shall be heated to its melting temperature. A number of cylindrical tensile test specimens are used, which can be loaded to failure at a predefined point (Procedure A). To simulate the HAZ thermal history and liquation cracking, the specimen is heated only as far as the nil strength temperature
43、(NST) rather than the melting point. This procedure is the same for both liquation cracking in the HAZ of parent materials and the interrun HAZs of multipass welds (Procedure B). The test procedures are primarily used in weld metal hot cracking studies. The tests are characterised by good reproducib
44、ility. 6.1.2 Specimen size Procedure A to simulate solidification cracking and heating to the melting point, a specimen of length 130 mm and diameter 10 mm should be used. Procedure B to simulate HAZ liquation cracking and to determine the NST, a specimen of length 110 mm and diameter 6 mm should be
45、 used. The specimen dimension together with the location of the weld joint are shown in Figure 1. Dimensions in millimetres Key 1 Weld metal a = 130 for solidification cracking 110 for liquation cracking 1 )for liquation cracking 2)for solidification cracking Figure 1 Specimen dimensions for the hot
46、 tensile test 7egaP 5002:314671RT/OSIECPage7 CENISO/TR176413:2005I NECS/OTR -14671:302( 50E) 8 6.1.3 Protective atmosphere The test specimens shall be heated in a chamber, which is first evacuated and then back-filled with Argon to prevent excessive oxidation at high temperature. Any suitable means
47、of back filling can be used, provided the oxygen content of the atmosphere at the start of the test does not exceed 0,1 %. 6.1.4 Test procedure 6.1.4.1 General Temperature measurement of the specimen should be carried out by percussion welding a 0,2/0,25mm diameter Pt-PtRh thermocouple fixed to midd
48、le of the specimen length and perpendicular to the diameter of the specimen. 6.1.4.2 Procedure A Solidification cracking studies The 10 mm diameter specimen is mounted in water cooled copper jaws and then heated to the melting point using controlled resistance heating. The central portion of the specimen is prevented from collapse, as it nears the melting point, by a close-fitting quartz tube. During solidification and on further cooling the jaws are held fixed so that the shrinkage strain
