SIST-TP CEN ISO/TR 14745:2015
(Main)Welding - Post-weld heat treatment parameters for steels (ISO/TR 14745:2015)
Welding - Post-weld heat treatment parameters for steels (ISO/TR 14745:2015)
This Technical Report provides 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 and are independent of type of product or location.
The recommendations do not supersede any guidance given in material supplier specifications, e.g.
thermomechanically treated fine-grain steels.
This Technical Report does not specify when PWHT is required. Such requirements are given in product
standards, material specifications or material data sheets.
Soudage - Paramètres de traitement thermique après soudage des aciers (ISO/TR 14745:2015)
Varjenje - Parametri toplotne obdelave po varjenju za jeklo (ISO/TR 14745:2015)
To tehnično poročilo vsebuje priporočila glede toplotne obdelave po varjenju za jeklo (PWHT) s priporočili za temperature in trajanje shranjevanja za različne materiale in debeline materialov. Ta priporočila so omejena na odpravo napetosti in so neodvisna od vrste ali lokacije izdelka. Priporočila ne nadomeščajo katerih koli smernic, podanih v specifikaciji materiala, ki jo je zagotovil proizvajalec, npr. termomehansko obdelana drobnozrnata jekla. To poročilo ne določa, kdaj je potrebna toplotna obdelava po varjenju. Te zahteve so navedene v standardih za izdelke, specifikacijah materiala ali listih s podatki o materialu.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TP CEN ISO/TR 14745:2015
01-marec-2015
Varjenje - Parametri toplotne obdelave po varjenju za jeklo (ISO/TR 14745:2015)
Welding - Post-weld heat treatment parameters for steels (ISO/TR 14745:2015)
Soudage - Paramètres de traitement thermique après soudage des aciers (ISO/TR
14745:2015)
Ta slovenski standard je istoveten z: CEN ISO/TR 14745:2015
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
77.080.20 Jekla Steels
SIST-TP CEN ISO/TR 14745:2015 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TP CEN ISO/TR 14745:2015
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SIST-TP CEN ISO/TR 14745:2015
TECHNICAL REPORT
CEN ISO/TR 14745
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
January 2015
ICS 25.160.01
English Version
Welding - Post-weld heat treatment parameters for steels
(ISO/TR 14745:2015)
Soudage - Paramètres de traitement thermique après
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, 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 STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR 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 Ref. No. CEN ISO/TR 14745:2015 E
worldwide for CEN national Members.
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CEN ISO/TR 14745:2015 (E)
Contents Page
Foreword .3
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SIST-TP CEN ISO/TR 14745:2015
CEN ISO/TR 14745:2015 (E)
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 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 14745:2015 without any
modification.
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SIST-TP CEN ISO/TR 14745:2015
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SIST-TP CEN ISO/TR 14745:2015
TECHNICAL ISO/TR
REPORT 14745
First edition
2015-01-15
Welding — Post-weld heat treatment
parameters for steels
Soudage — Paramètres de traitement thermique après soudage des
aciers
Reference number
ISO/TR 14745:2015(E)
©
ISO 2015
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SIST-TP CEN ISO/TR 14745:2015
ISO/TR 14745:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2015 – All rights reserved
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SIST-TP CEN ISO/TR 14745:2015
ISO/TR 14745:2015(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms 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 . 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
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ISO/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. 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 International 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
different 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 shall 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 is 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 ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) 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 Report 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.
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SIST-TP CEN ISO/TR 14745:2015
TECHNICAL REPORT ISO/TR 14745:2015(E)
Welding — Post-weld heat treatment parameters for steels
1 Scope
This Technical Report provides 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 tempering 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 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 application. 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 Terms and definitions
For the purposes of this document, the terms 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 temperature
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 temperature range.
[SOURCE: ISO 17663:2009, 3.3]
3.4
holding time
time the product or component is kept at the holding temperature
Note 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.
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Note 2 to entry: The holding time depends on the type of heat treatment, material, and material thickness.
[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 Hollomon–Jaffe parameter
t material thickness, 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 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 indicating 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 Table 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 connecting 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);
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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 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 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 value is introduced. This parameter, a critical Hollomon–Jaffe value, should not be
crit
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 temperature 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 cooling can be
taken out of the relevant product standards. If required by application standards or specifications, the
PWHT cycle
...
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