1、BSI Standards PublicationPD CEN ISO/TR 14745:2015Welding Post-weld heattreatment parameters forsteelsPD CEN ISO/TR 14745:2015 PUBLISHED DOCUMENTNational forewordThis Published Document is the UK implementation of CEN ISO/TR14745:2015.The UK participation in its preparation was entrusted to Technical
2、Committee WEE/-/1, Briefing committee for welding.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Sta
3、ndards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 79164 2ICS 25.160.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 31 January 2015
4、.Amendments issued since publicationDate Text affectedTECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN ISO/TR 14745 January 2015 ICS 25.160.01 English Version Welding - Post-weld heat treatment parameters for steels (ISO/TR 14745:2015) Soudage - Paramtres de traitement thermique aprs souda
5、ge des aciers (ISO/TR 14745:2015) This Technical Report was approved by CEN on 15 December 2014. It has been drawn up by the Technical Committee CEN/TC 121. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former
6、 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. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EU
7、ROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN ISO/TR 14745:2015 EPD CEN ISO/TR 14745:2015CEN ISO/TR 1474
8、5:2015 (E) 3 Foreword This document (CEN ISO/TR 14745:2015) has been prepared by Technical Committee ISO/TC 44 “Welding and allied processes” in collaboration with Technical Committee CEN/TC 121 “Welding and allied processes” the secretariat of which is held by DIN. Attention is drawn to the possibi
9、lity that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of ISO/TR 14745:2015 has been approved by CEN as CEN ISO/TR 14745:2015 without any modifica
10、tion. PD CEN ISO/TR 14745:2015ISO/TR 14745:2015(E)Contents PageForeword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Symbols and abbreviated terms . 24.1 Symbols . 24.2 Abbreviated terms . 25 General information . 26 Heat treatment conditions . 27 Application of PWHT 47.1 Genera
11、l . 47.2 Heating and cooling 47.3 Heating in a furnace 78 Post-weld heat treatment of dissimilar ferritic joints . 88.1 General . 88.2 Holding temperature . 8Annex A (informative) Additional information about PWHT . 9Bibliography .11 ISO 2015 All rights reserved iiiPD CEN ISO/TR 14745:2015ISO/TR 147
12、45:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for
13、which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on al
14、l matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. Th
15、is document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or
16、 all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users
17、and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary
18、informationThe committee responsible for this document is ISO/TC 44, Welding and allied processes, Subcommittee SC 10, Unification requirements in the field of metal welding.Requests for official interpretations of any aspect of this Technical Report should be directed to the Secretariat of ISO/TC 4
19、4/SC 10 via your national standards body. A complete listing of these bodies can be found at www.iso.org.iv ISO 2015 All rights reservedPD CEN ISO/TR 14745:2015Welding Post-weld heat treatment parameters for steels1 ScopeThis Technical Report provides recommendations for post-weld heat treatment (PW
20、HT) of steels with recommendations for holding temperatures and holding times for different materials and material thicknesses. These recommendations are limited to stress relieving for non-alloy steels (groups 1, 2, 3, 4, and 11) and to tempering for Cr-Mo-(Ni) steels (groups 5 and 6) and martensit
21、ic stainless steels (group 7.2), and are independent of type of product or location. The recommendations do not supersede any guidance given in material supplier specifications, e. g. thermo-mechanically treated fine-grain steels.This Technical Report does not specify when PWHT is required. Such req
22、uirements are given in product standards, material specifications, or material data sheets.2 Normative referencesThe 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.
23、For undated references, the latest edition of the referenced document (including any amendments) applies.EN 10052, Vocabulary of heat treatment terms for ferrous products3 Terms and definitionsFor the purposes of this document, the terms and definitions given in EN 10052 and the following apply.3.1c
24、ooling ratevariation in temperature as a function of time during cooling cycleSOURCE: ISO 4885:1996, 3.373.2heating ratevariation in temperature as a function of time during heating cycleSOURCE: ISO 4885:1996, 3.783.3holding temperaturetemperature at which the product or component is kept in order t
25、o achieve specified propertiesNote 1 to entry: The holding temperature depends on the type of heat treatment, type of material, and material thickness.Note 2 to entry: Normally the holding temperature is expressed as a temperature range.SOURCE: ISO 17663:2009, 3.33.4holding timetime the product or c
26、omponent is kept at the holding temperatureNote 1 to entry: The holding time starts when the temperature in all measuring points has reached the minimum value of the range of the holding temperature and stops when one of the measuring points falls below that temperature.TECHNICAL REPORT ISO/TR 14745
27、:2015(E) ISO 2015 All rights reserved 1PD CEN ISO/TR 14745:2015ISO/TR 14745:2015(E)Note 2 to entry: The holding time depends on the type of heat treatment, material, and material thickness.SOURCE: ISO 17663:2009, 3.43.5post-weld heat treatmentPWHTheat treatment carried out after welding in order to
28、decrease residual welding stress, and/or to adjust to desired properties and/or the microstructure4 Symbols and abbreviated terms4.1 SymbolsP HollomonJaffe parametert material thickness, in mmNOTE Symbols other than those specified here are used in other International Standards.4.2 Abbreviated terms
29、NT normalized and temperedPWHT post-weld heat treatmentQT quenched and tempered5 General informationPWHT should be performed in accordance with a written procedure which describes the parameters critical to the PWHT process.Equipment used for the PWHT should be suitable according to ISO 17663. It sh
30、ould permit the temperature control of the component with adequate accuracy and uniformity. The PWHT of products or components should be recorded by the manufacturer indicating the holding temperature, holding time, and the heating- and cooling-rate.6 Heat treatment conditionsPWHT, with the exceptio
31、n of those materials mentioned in Clause 8, should be applied to steels in accordance with Table 1 upon completion of welding. If PWHT of materials, not listed in Table 1, is considered necessary, the PWHT holding time and holding temperature should take into account recommendations of the applicati
32、on standard, as well as the recommendations of the material and welding consumable manufacturer to achieve the required material properties.Where welded joints are connecting parts with different thicknesses, the thickness to be used in applying the requirements for PWHT should be as follows:a) for
33、butt welds (excluding in T joints), the thickest part of the weld of the two parts (see Figure 1);2 ISO 2015 All rights reservedPD CEN ISO/TR 14745:2015ISO/TR 14745:2015(E)Keys weld thicknessFigure 1 Example of thickest part of the weldb) for butt welds in T joints, the thickness of the weld;c) for
34、fillet welds, the throat thickness of the weld;d) for butt-welded set-on nozzles, the thickness of the nozzle;e) for set-through nozzles, the thickness of the plate or shell;f) for set-in nozzles, the thickness of the weld.PWHT may be carried out on steels of thickness lower than those specified by
35、Table 1. Such instances may include products subject to stress corrosion cracking or at risk of brittle fracture.When additional welds or weld repairs have been made after PWHT, a further heat treatment is normally carried out. The thickness to be used in defining the holding time required at temper
36、ature should be the thickness of the weld applied after the PWHT.In Table 1, a Pcritvalue is introduced. This parameter, a critical HollomonJaffe value, should not be exceeded without proving the mechanical properties.PWHT as per Table 1, particularly in the upper range of holding temperature and/or
37、 holding time, may unduly impair the physical properties, e. g. yield strength, tensile strength, and toughness of the material.A higher PWHT temperature than tempering temperature for NT- and QT-materials could impair the mechanical properties of the material.The whole PWHT cycle consisting of heat
38、ing rate, holding temperature, holding time, and cooling rate can have an essential influence on the mechanical properties. The data for heating and cooling can be taken out of the relevant product standards. If required by application standards or specifications, the PWHT cycle should be qualified
39、by a procedure test including parent metal. This belongs especially for multi-PWHT cycles.The additional effect of multiple heating cycles should be considered. This effect is explained by the Hollomon-Jaffe parameter, P,4as given inPT ts=+()20 103lgh(1)whereTsis the holding temperature, in Kelvin;t
40、his the holding time, in hours.NOTE The Hollomon-Jaffe parameter describes the effect of tempering for a certain time, t, at a certain temperature, T, and a parameter, C, that is unique to the material used. This mathematical relationship has proved to be of particular value in highly complex weldin
41、g procedure qualifications where considerable costs can arise by application of multiple-stage PWHT in the production process. The Hollomon-Jaffe parameter may be used in the calculation and application of more cost effective single-cycle PWHT. ISO 2015 All rights reserved 3PD CEN ISO/TR 14745:2015I
42、SO/TR 14745:2015(E)7 Application of PWHT7.1 GeneralPWHT can be applied with a furnace or with local heating (e.g. induction or resistance). Reference should be made to ISO 17663 for the methods of application.The PWHT temperatures and times should be in accordance with Table 1.7.2 Heating and coolin
43、gDuring the heating and cooling periods, for temperatures up to 500 C, variation in temperature throughout the product or component should not exceed 150 C within 4 500 mm and the temperature gradient should be gradual. Above 500 C, this variation should not exceed 100 C.When the product or componen
44、t has attained a uniform holding temperature (see Table 1), this temperature should be held for the period specified in Table 1.Table 1 PWHT parameters for steelMaterial group (ISO/TR 15608)Material Holding tempera- tureMaterial thicknessatHolding timePcrit(see Clause 6)C mm min1.1 Steels with ReH 2
45、75 MPa 550 to 600 t 35a35 9030t 540 + 0,5t17,5 16Mo3 550 to 6201.2 Steels with 275 MPa 9030t 540 + 0,5t17,3 delivery condition QT 550 to 600b17,5 delivery condition N (except 16Mo3)550 to 600 17,5 16Mo3, 18MnMo45 and 18 Mo5 550 to 620 17,51.3 Normalized fine-grain steels with ReH 360 MPa530 to 580 1
46、7,32.1 Thermomechanically treated fine-grain steels with 360 MPa 460 MPad3.1 Quenched and tempered fine-grain steels with 360 MPa 690 MPad4.1 Low vanadium alloyed Cr-Mo-(Ni) steels with, by mass: Mo 0,7 %; V 0,1 %; Cr 0,3 %; Ni 0,7 %4 ISO 2015 All rights reservedPD CEN ISO/TR 14745:2015ISO/TR 14745:
47、2015(E)Material group (ISO/TR 15608)Material Holding tempera- tureMaterial thicknessatHolding timePcrit(see Clause 6)C mm min 18NiCuMoNb55 580 to 640bt 15c15 90302t120 15MnCrMoNiV53d4.2 Low vanadium alloyed Cr-Mo-(Ni) steels with, by mass: Mo 0,7 %; V 0,1 %; Cr 0,7 %; Ni 1,5 % 15NiCuMoNb56-4 530 to
48、620 t 2020 903060t, min 6040 + t5.1 Cr-Mo-steels free of vanadium with, by mass: 0,75 % 60302t60 + t18,7 13CrMo45 630 to 700g All others 620 to 680g18,55.2 Cr-Mo-steels free of vanadium with, by mass: 1,5 % 60302t60 + t19,2 11CrMo910h660 to 720b 12CrMo910 660 to 720b,it 125t 1252,4t225 + 0,6t19,35.3
49、 Cr-Mo-steels free of vanadium with, by mass: 3,5 % 60302t60 + t19,5 X16CrMo51 700 to 750 5.4 Cr-Mo-steels free of vanadium with, by mass: 7 % Cr 10 %; 0,7 % 60302,5t90 + t6.1 High vanadium alloyed Cr-Mo-(Ni) steels with, by mass: 0,3 % 1252,4t225 + 0,6t19,4 13CrMoV12106.3 High vanadium alloyed Cr-Mo-(Ni) steels with, by mass: 3,5 % 60302t, min 60 90 + t20,5 X10CrWMoVNb92 740 to 770jt 1212 60302t, min 60 90 + t X20CrMoV111 X20CrMoNiV 11
