ISO 9328-3:2018

INTERNATIONAL ISO
STANDARD 9328-3
Fourth edition
2018-02
Steel flat products for pressure
purposes — Technical delivery
conditions —
Part 3:
Weldable fine grain steels, normalized
Produits plats en acier pour service sous pression — Conditions
techniques de livraison —
Partie 3: Aciers soudables à grains fins, normalisés
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification and designation . 1
4.1 Classification . 1
4.2 Designation . 2
5 Information to be supplied by the purchaser. 2
5.1 Mandatory information . 2
5.2 Options . 2
5.3 Example for ordering . 3
6 Requirements . 3
6.1 Steelmaking process . 3
6.2 Delivery condition . 3
6.3 Chemical composition . 3
6.4 Mechanical properties . 4
6.5 Surface condition . 4
6.6 Internal soundness . 5
6.7 Weldability . 5
6.8 Dimensions and tolerances . 5
6.9 Calculation of mass . 5
6.10 Resistance to hydrogen-induced cracking. 5
7 Inspection . 6
7.1 Types of inspection and inspection documents . 6
7.2 Tests to be carried out . 6
7.3 Retests, sorting and reprocessing . 6
8 Sampling . 6
9 Test methods . 6
10 Marking . 6
Annex A (normative) Chemical composition and mechanical properties of products
delivered in accordance with European design codes . 7
Annex B (normative) Chemical composition and mechanical properties of products
delivered in accordance with ASME-type design codes.13
Annex C (informative) Steel designations in accordance with this document and
designation of comparable steel grades in national or regional standards .17
Annex D (informative) Evaluation of resistance to hydrogen-induced cracking .18
Bibliography .19
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 voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 10, Steel for
pressure purposes.
This fourth edition cancels and replaces the third edition (ISO 9328-3:2011), which has been technically
revised. The following changes have been made:
— the term “product thickness” has been replaced with “nominal thickness”;
— classification of the steels, examples of ordering and statements concerning weldability have been
revised;
— the technical data in Annex A have been aligned with EN 10028-3.
— in Table B.1, “B ≤ 0,001 0” has been added and the specifications of “P” and “S” have been changed.
A list of all the parts in the ISO 9328 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 9328-3:2018(E)
Steel flat products for pressure purposes — Technical
delivery conditions —
Part 3:
Weldable fine grain steels, normalized
1 Scope
This document specifies the requirements for flat products for pressure equipment made of weldable
fine grain steels as specified in Tables A.1 and B.1. The requirements and definitions of ISO 9328-1 also
apply to this document.
NOTE 1 Fine grain steels are understood as steels with a ferritic grain size of 6 or finer when tested in
accordance with ISO 643.
NOTE 2 This document offers the possibility to specifying products in accordance with European design
codes and ASME-type design codes.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
ISO 4948-1, Steels — Classification — Part 1: Classification of steels into unalloyed and alloy steels based
on chemical composition
ISO 4948-2, Steels — Classification — Part 2: Classification of unalloyed and alloy steels according to main
quality classes and main property or application characteristics
ISO 9328-1:2018, Steel flat products for pressure purposes — Technical delivery conditions — Part 1:
General requirements
EN 10314, Method for the derivation of minimum values of proof strength of steel at elevated temperatures
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9328-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
4 Classification and designation
4.1 Classification
4.1.1 The steel grades covered by this document are given in four qualities:
a) the room temperature quality (P.N; PT…N);
b) the elevated temperature quality (P.NH; PT…NH);
c) the low temperature quality (P.NL1; PT…NL1);
d) the special low temperature quality (P.NL2).
4.1.2 In accordance with ISO 4948-1 and ISO 4948-2, the grades P275NH, P275NL1, P355N, P355NH,
P355NL1, P355NL2, PT400N, PT400NH, PT400NL1, PT440N, PT440NH, PT440NL1, PT490N and
PT490NH are alloy-quality steels, the grades P275NL2 and the grades P420NH, P420NL1, P420NL2,
P460NH, P460NL1, P460NL2, PT520N and PT520NH are alloyed special steels.
4.2 Designation
Shall be in accordance with ISO 9328-1.
NOTE 1 Steel grades in Annex A are classified in accordance with their yield strength; steel grades in Annex B
are classified in accordance with their tensile strength.
NOTE 2 Information on the designation of comparable steel grades in national or regional standards is given
in Annex C.
5 Information to be supplied by the purchaser
5.1 Mandatory information
Shall be in accordance with ISO 9328-1.
Additionally, for steel grades in accordance with Annex B, the test direction for the impact test shall be
b
agreed upon (see 9.2 and Table B.4, footnote ).
5.2 Options
A number of options are specified in this document. These are listed below under a) to r). Additionally,
the relevant options of ISO 9328-1 apply. If the purchaser does not indicate a wish to implement any of
these options at the time of enquiry and order, the products shall be supplied in accordance with the
basic specification (see ISO 9328-1):
a) delivery condition other than specified in Tables A.3 and B.3 (see 6.2.1);
b) tests in the simulated normalized condition (see 6.2.2);
c) delivery of products in the untreated condition (see 6.2.3);
d) maximum carbon-equivalent value (see 6.3.3);
e) specification of an impact energy value of 40 J (see Note to 6.4.1 and Table A.
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