1、BSI Standards Publication PD CEN ISO/TR 14745:2015 Welding Post-weld heat treatment parameters for steelsPD CEN ISO/TR 14745:2015 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of CEN ISO/TR 14745:2015. The UK participation in its preparation was entrusted to T
2、echnical Committee WEE/-/1, Briefing committee for welding. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. T
3、he British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 79164 2 ICS 25.160.01 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy Committ
4、ee on 31 January 2015. Amendments issued since publication Date Text affected TECHNICAL 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 traitem
5、ent thermique aprs soudage 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,
6、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. EUROPEAN COMMITTEE FOR
7、STANDARDIZATION COMIT EUROPEN 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 1
8、4745:2015 CEN ISO/TR 14745:2015 (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. Attentio
9、n is drawn to the possibility 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:
10、2015 without any modification. PD CEN ISO/TR 14745:2015ISO/TR 14745:2015(E)Contents Page Foreword iv 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Symbols and abbreviated terms . 2 4.1 Symbols . 2 4.2 Abbreviated terms . 2 5 General information . 2 6 Heat treatment conditions .
11、 2 7 Application of PWHT 4 7.1 General . 4 7.2 Heating and cooling 4 7.3 Heating in a furnace 7 8 Post-weld heat treatment of dissimilar ferritic joints . 8 8.1 General . 8 8.2 Holding temperature . 8 Annex A (informative) Additional information about PWHT . 9 Bibliography .11 ISO 2015 All rights re
12、served iiiPD CEN ISO/TR 14745:2015ISO/TR 14745:2015(E) Foreword ISO (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.
13、 Each member body interested in a subject for 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 Interna
14、tional Electrotechnical Commission (IEC) on all 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 diffe
15、rent types of ISO documents should be noted. This 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 shal
16、l not be held responsible for identifying any or 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 i
17、s information given for the convenience of users 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
18、) see the following URL: Foreword - Supplementary information The 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 Repo
19、rt should be directed to the Secretariat of ISO/TC 44/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 steels 1 Scope This Technical Report pro
20、vides recommendations for post-weld heat treatment (PWHT) 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 temperin
21、g for Cr-Mo-(Ni) steels (groups 5 and 6) and martensitic 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
22、Report does not specify when PWHT is required. Such requirements are given in product standards, material specifications, or material data sheets. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its applicatio
23、n. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 10052, Vocabulary of heat treatment terms for ferrous products 3 T erms a nd definiti ons For the purposes of this document, the terms
24、 and definitions given in EN 10052 and the following apply. 3.1 cooling rate variation in temperature as a function of time during cooling cycle SOURCE: ISO 4885:1996, 3.37 3.2 heating rate variation in temperature as a function of time during heating cycle SOURCE: ISO 4885:1996, 3.78 3.3 holding te
25、mperature temperature at which the product or component is kept in order to achieve specified properties Note 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 tempe
26、rature range. SOURCE: ISO 17663:2009, 3.3 3.4 holding time time the product or component is kept at the holding temperature Not e 1 t o ent r y : T he hold ing t ime s t a r t s when t he t emper at u re in a l l mea su r ing point s ha s reached t he m in imu m v a lue of the range of the holding t
27、emperature and stops when one of the measuring points falls below that temperature. TECHNICAL REPORT ISO/TR 14745:2015(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 thickne
28、ss. SOURCE: ISO 17663:2009, 3.4 3.5 post-weld heat treatment PWHT heat treatment carried out after welding in order to decrease residual welding stress, and/or to adjust to desired properties and/or the microstructure 4 Symbols and abbreviated terms 4.1 Symbols P HollomonJaffe parameter t material t
29、hickness, in mm NOTE Symbols other than those specified here are used in other International Standards. 4.2 Abbreviated terms NT normalized and tempered PWHT post-weld heat treatment QT quenched and tempered 5 General information PWHT should be performed in accordance with a written procedure which
30、describes the parameters critical to the PWHT process. Equipment used for the PWHT should be suitable according to ISO 17663. It should permit the temperature control of the component with adequate accuracy and uniformity. The PWHT of products or components should be recorded by the manufacturer ind
31、icating the holding temperature, holding time, and the heating- and cooling-rate. 6 Heat treatment conditions PWHT, with the exception 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 Tabl
32、e 1, is considered necessary, the PWHT holding time and holding temperature should take into account recommendations of the application standard, as well as the recommendations of the material and welding consumable manufacturer to achieve the required material properties. Where welded joints are co
33、nnecting parts with different thicknesses, the thickness to be used in applying the requirements for PWHT should be as follows: a) for 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:
34、2015(E) Key s weld thickness Figure 1 Example of thickest part of the weld b) for butt welds in T joints, the thickness of the weld; c) for 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
35、 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 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
36、 been made after PWHT, a further heat treatment is normally carried out. The thickness to be used in defining the holding time required at temperature should be the thickness of the weld applied after the PWHT. In Table 1, a P critvalue is introduced. This parameter, a critical HollomonJaffe value,
37、should not be exceeded without proving the mechanical properties. PWHT as per Table 1, particularly in the upper range of holding temperature and/or holding time, may unduly impair the physical properties, e. g. yield strength, tensile strength, and toughness of the material. A higher PWHT temperatu
38、re than tempering temperature for NT- and QT-materials could impair the mechanical properties of the material. The whole PWHT cycle consisting of heating rate, holding temperature, holding time, and cooling rate can have an essential influence on the mechanical properties. The data for heating and c
39、ooling can be taken out of the relevant product standards. If required by application standards or specifications, the PWHT cycle should be qualified by a procedure test including parent metal. This belongs especially for multi-PWHT cycles. The additional effect of multiple heating cycles should be
40、considered. This effect is explained by the Hollomon-Jaffe parameter, P, 4as given in (1) where T s is the holding temperature, in Kelvin; t h is 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
41、parameter, C, that is unique to the material used. This mathematical relationship has proved to be of particular value in highly complex welding procedure qualifications where considerable costs can arise by application of multiple-stage PWHT in the production process. The Hollomon-Jaffe parameter m
42、ay be used in the calculation and application of more cost effective single-cycle PWHT. ISO 2015 All rights reserved 3PD CEN ISO/TR 14745:2015ISO/TR 14745:2015(E) 7 Application of PWHT 7.1 General PWHT can be applied with a furnace or with local heating (e.g. induction or resistance). Reference shou
43、ld 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 cooling During the heating and cooling periods, for temperatures up to 500 C, variation in temperature throughout the product or component should not exceed 1
44、50 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 component has attained a uniform holding temperature (see Table 1), this temperature should be held for the period specified in Table 1. Table 1 PWHT paramete
45、rs for steel Material group (ISO/TR 15608) Material Holding tempera- ture Material thickness at Holding time P crit(see Clause 6) C mm min 1.1 Steels with R eH 275 MPa 550 to 600 t 35 a 35 90 30 t 5 40 + 0,5t 17, 5 16Mo3 550 to 620 1.2 Steels with 275 MPa 90 30 t 5 40 + 0,5t 17, 3 delivery condition
46、 QT 550 to 600 b 17, 5 delivery condition N (except 16Mo3) 550 to 600 17, 5 16Mo3, 18MnMo45 and 18 Mo5 550 to 620 17, 5 1.3 Normalized fine-grain steels with R eH 360 MPa 530 to 580 17, 3 2.1 Thermomechanically treated fine-grain steels with 360 MPa 460 MPa d 3.1 Quenched and tempered fine-grain ste
47、els with 360 MPa 690 MPa d 4.1 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 14745:2015(E) Material group (ISO/TR 15608) Material Holding tempera- ture Material thickness at Holding time P crit(
48、see Clause 6) C mm min 18NiCuMoNb55 580 to 640 b t 15 c 15 90 30 2t 120 15MnCrMoNiV53 d 4.2 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 620 t 20 20 90 30 60 t, min 60 40 + t 5.1 Cr-Mo-steels free of vanadium with, by mass: 0,75 %
49、60 30 2t 60 + t 18,7 13CrMo45 630 to 700 g All others 620 to 680 g 18,5 5.2 Cr-Mo-steels free of vanadium with, by mass: 1,5 % 60 30 2t 60 + t 19,2 11CrMo910 h 660 to 720 b 12CrMo910 660 to 720 b,i t 125 t 125 2,4t 225 + 0,6t 19,3 5.3 Cr-Mo-steels free of vanadium with, by mass: 3,5 % 60 30 2t 60 + t 19,5 X16CrMo51 700 to 750 5.4 Cr-Mo-steels free of vanadium with, by mass: 7 % Cr 10 %; 0,7 % 60 30 2,5t 90 + t 6.1 High
