ISO 630-5:2023

INTERNATIONAL ISO
STANDARD 630-5
Second edition
2023-12
Structural steels —
Part 5:
Technical delivery conditions for
structural steels with improved
atmospheric corrosion resistance
Aciers de construction —
Partie 5: Conditions techniques de livraison pour aciers de
construction à résistance améliorée à la corrosion atmosphérique
Reference number
© ISO 2023
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Classification and designation . 2
4.1 Classification . 2
4.2 Designation (grades and qualities) . 2
5 Information to be supplied by purchaser . 3
5.1 Mandatory information . 3
5.2 Options. 3
6 Requirements . 3
6.1 Steelmaking process . 3
6.2 Delivery condition . 3
6.3 Chemical composition . 3
6.3.1 Heat analysis . 3
6.3.2 Product analysis . 3
6.3.3 Carbon equivalent value . 4
6.4 Mechanical properties . 4
6.4.1 Tensile properties . . 4
6.4.2 Charpy V-notch impact properties . 4
6.5 Surface conditions . 4
6.6 Internal soundness . 4
6.7 Dimensions, tolerances on dimensions and shape and mass . 4
7 Inspection . 4
8 Sampling — Frequency of testing .4
8.1 Verification . . 4
8.2 Test units . 5
8.2.1 Test units for grades S235, S295, S355, S420, S460, S500, S550 . 5
8.2.2 Test units for grades SG245, SG345, SG365, SG400, SG460, SG500, SG700 . 5
9 Test methods . 5
10 Marking . . 5
11 Information about technological properties . 5
11.1 Weldability . 5
11.2 Use of steel with improved corrosion resistance . 5
Annex A (normative) Steel grades S235, S295, S355, S420, S460, S500, S550: Chemical
composition and mechanical properties . 6
Annex B (normative) Steel grades SG245, SG345, SG365, SG400, SG460, SG500, SG700:
Chemical composition and mechanical properties.14
Annex C (informative) Notes on weldability .20
Annex D (informative) Additional information for the use of steel with improved
atmospheric corrosion resistance .21
Bibliography .22
iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had received notice of
(a) patent(s) which may be required to implement this document. However, implementers are cautioned
that this may not represent the latest information, which may be obtained from the patent database
available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent
rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 3, Steels for
structural purposes.
This second edition cancels and replaces the first edition (ISO 630-5:2014), which has been technically
revised.
The main changes are as follows:
— grades S295W, S355WSE, S420W, S460W, S500W, S550W and pertaining requirements have been
added;
— applicable thickness ranges have been added in the scope;
— terms and definitions concerning heat treatments have been deleted because defined in ISO 630-1;
— quality E (impact testing at −40 °C) has been added;
— list of options has been integrated in ISO 630-1;
— test units have been updated;
— Bibliography has been updated;
— the content of the document has been updated to harmonize with the other parts of the ISO 630
series.
A list of all parts in the ISO 630 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
INTERNATIONAL STANDARD ISO 630-5:2023(E)
Structural steels —
Part 5:
Technical delivery conditions for structural steels with
improved atmospheric corrosion resistance
1 Scope
This document specifies qualities for flat and long products of hot-rolled structural steels with improved
atmospheric corrosion resistance in the as-rolled, normalized/normalized rolled, thermomechanical
control processed and quenched and tempered delivery conditions. It is applicable to steel plates rolled
on a reversing mill, wide flats, hot-rolled sections and bars, which are intended for use in welded or
bolted structures.
This document covers 14 grades and 5 qualities. Grades S235, S295, S355, S420, S460, S500 and S550
are covered in Annex A. Grades SG245, SG345, SG365, SG400, SG460, SG500, and SG700 are covered
in Annex B. Not all grades are available in all qualities, and some qualities have Charpy V-notch
requirements.
The steels specified in this document are applicable to hot-rolled plates, wide flats, sections and bars
with a maximum nominal thickness of 150 mm for grades S235W, S295W, S355W, S420W, S460W,
S500W and S550W, with a maximum nominal thickness of 200 mm for grades SG245, SG345, SG365,
SG400, SG460, SG500, and SG700.
The steels specified in this document are applicable to hot-rolled plates with a maximum nominal
thickness of 20 mm for grades S295WP and S355WP.
The steels specified in this document are applicable to hot-rolled wide flats, sections and bars with a
maximum nominal thickness of 40 mm for grades S295WP and S355WP.
The steels specified in this document are applicable to hot-rolled plates with a maximum nominal
thickness of 80 mm for grade S355WSE.
This document does not include the following structural steels, some of which are covered by other
International Standards.
— sheet and strip, e.g. ISO 4995 or ISO 4996;
— tubular products. e.g. ISO 12633-1, ISO 12633-2.
NOTE In this document, the term of "thickness" is considered as "nominal thickness", unless otherwise
stated.
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 630-1, Structural steels — Part 1: General technical delivery conditions for hot-rolled products
ISO 643, Steels — Micrographic determination of the apparent grain size
ISO 4948-1, Steels — Classification — Part 1: Classification of steels into unalloyed and alloy steels based
on chemical composition
ISO 10474, Steel and steel products — Inspection documents
ASTM G101, Standard Guide for Estimating the Atmospheric Corrosion Resistance of Low-Alloy Steels
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 630-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
fine-grain steel
steel with fine grain structure with an equivalent index of ferritic grain size ≥6 determined in
accordance with specific requirements
Note 1 to entry: The requirements shall be in accordance with ISO 643.
Note 2 to entry: See 6.1.
3.2
steel with improved atmospheric corrosion resistance
steel in which a certain number of alloying elements, such as P, Cu, Cr, Ni, etc., have intentionally been
added in order to increase its resistance to atmospheric corrosion, by forming an auto-protective oxide
layer on the base metal
Note 1 to entry: These steels are commonly known as “weathering steels”.
Note 2 to entry: For additional information for the use of steel with improved atmospheric corrosion resistance,
see Annex D.
4 Classification and designation
4.1 Classification
The steel grades specified in this document shall be classified as unalloyed or alloy steels in accordance
with ISO 4948-1.
4.2 Designation (grades and qualities)
Steel grades and qualities differ in their specified mechanical properties and impact energy
requirements.
Grades S295 and SG345 are subdivided into classes W and WP, which differ primarily in their
phosphorus contents; grade S355 is subdivided into classes W, WP and WSE, which differ primarily in
phosphorus content and alloying element requirements for Sn, Cr, Mo and Cu; grades SG245, SG365, and
SG460 are subdivided into classes W1 and W2, which differ primarily in alloying element requirements
for Si, Cr, Cu and Ni (see Table B.1). Class W denotes weathering steel; class WP denotes weathering steel
with higher levels of phosphorus; class WSE denotes weathering steel with an improved resistance to
saline environments.
— Quality A: no impact testing
— Quality B: impact testing at +20 °C
— Quality C: impact testing at 0 °C
— Qualities D and D1: impact testing at –20 °C
— Quality E: impact testing at –40 °C
NOTE Quality D1 specifies a higher minimum impact energy than D.
5 Information to be supplied by purchaser
5.1 Mandatory information
The information that shall be supplied by the purchaser at the time of the order is specified in ISO 630-1.
5.2 Options
The options of ISO 630-1 may apply.
6 Requirements
6.1 Steelmaking process
The steel making process shall be in accordance with ISO 630-1.
If a special steelmaking process has been specified, this shall be reported in the inspection document.
The steels shall contain sufficient amounts of nitrogen-binding elements and shall be fine-grain steel.
The steels specified in this specification shall be fully killed.
6.2 Delivery condition
Grades S235, S295 and S355 are delivered in the as-rolled, normalized rolled, normalized,
thermomechanical controlled processed or quenched and tempered condition. Grades S420, S460,
S500 and S550 are delivered in the thermomechanical controlled processed or quenched and tempered
condition. The delivery condition shall be indicated in the inspection document.
Grades SG245, SG345, SG365, SG400 and SG460 are delivered in the as-rolled, normalized rolled,
normalized, thermomechanical controlled processed or quenched and tempered condition. Grades
SG500 and SG700 are delivered in the thermomechanical controlled processed or quenched and
tempered condition. The delivery condition shall be indicated in the inspection document.
6.3 Chemical composition
6.3.1 Heat analysis
The chemical composition determined by heat analysis shall conform with the values given in Table A.1
or Table B.1.
6.3.2 Product analysis
The product analysis of grades S235, S295, S355, S420, S460, S500 and S550 shall conform with the
values given in Table A.2.
The permitted deviation of product analysis of SG245, SG345, SG365, SG400, SG460, SG500, and SG700
shall conform with the values given in Table B.2.
6.3.3 Carbon equivalent value
The maximum carbon equivalent value (C ) for grades S235, S295, S355, S420, S460, S500 and S550
EV
shall be in accordance with Table A.1.
The carbon equivalent value (C ) shall be determined using the IIW (International Institute for
EV
Welding) formula, given as Formula (1):
Mn Cr++Mo V Ni+Cu
C =+C + + (1)
EV
6 5 15
6.4 Mechanical properties
6.4.1 Tensile properties
The tensile properties at room temperature shall conform with the values given in Table A.3 or Table B.3
depending on the steel grade.
6.4.2 Charpy V-notch impact properties
The impact properties of Charpy V-notch test pieces shall conform with the values given in Table A.4 or
Table B.4 depending on the steel grade. The orientation of the specimens shall be longitudinal unless
transverse orientation is agreed between purchaser and manufacturer (see 5.2 and ISO 630-1).
The impact values for grades S295WP, S355WP shall be verified if agreed at the time of the order (see
Table A.4).
6.5 Surface conditions
Surface conditions shall be in accordance with ISO 630-1.
6.6 Internal soundness
Internal soundness shall be in accordance with ISO 630-1.
6.7 Dimensions, tolerances on dimensions and shape and mass
Dimensions, tolerances on dimensions and shape and mass shall be in accordance with ISO 630-1.
7 Inspection
The type of inspection (specific or non-specific) and the type of inspection document in accordance with
ISO 10474 shall be specified at the time of the order. Inspection shall be in accordance with ISO 630-1.
8 Sampling — Frequency of testing
8.1 Verification
The verification of mechanical properties shall be by heat. Verification by lot shall be by agreement
between the producer and purchaser.
8.2 Test units
8.2.1 Test units for grades S235, S295, S355, S420, S460, S500, S550
The test unit shall contain products of the same form, grade quality and delivery condition, and the
same thickness range as specified in Table A.3 for the yield strength and shall be taken by heat:
— 60 tonnes or part thereof;
— 80 tonnes or part thereof for heavy sections with a mass > 200 kg/m;
— 80 tonnes or part thereof for all sections if the mass of the heat exceeds 200 tonnes.
By agreement at time of order, two tests by heat can be used.
8.2.2 Test units for grades SG245, SG345, SG365, SG400, SG460, SG500, SG700
The test unit shall contain products of the same form, grade, quality and delivery condition, and the
same thickness range as specified in Table B.3 for the yield strength, and shall be 50 tonnes or part
thereof. By agreement at time of ordering, two tests by heat can be used.
9 Test methods
Test methods shall be in accordance with ISO 630-1.
10 Marking
Marking shall be in accordance with ISO 630-1.
11 Information about technological properties
11.1 Weldability
See Annex C for additional information about weldability.
11.2 U
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