BRITISH STANDARD BS EN 10120:2008

Steel sheet and

strip for welded gas
cylinders

ICS 77.140.30; 77.140.50

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

BS EN 10120:2008

National foreword

This British Standard is the UK implementation of EN 10120:2008. It

supersedes BS EN 10120:1997 which is withdrawn.
The UK participation in its preparation was entrusted to Technical
Committee ISE/73/2, Steel plates and bars for pressure purposes.
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.
Compliance with a British Standard cannot confer immunity
from legal obligations.

This British Standard Amendments/corrigenda issued since publication

was published under
the authority of the
Standards Policy and Date Comments
Strategy Committee on 30
September 2008
© BSI 2008

ISBN 978 0 580 59269 0

 BS EN 10120:2008

EUROPEAN STANDARD EN 10120

NORME EUROPÉENNE
EUROPÄISCHE NORM September 2008

ICS 77.140.50 Supersedes EN 10120:1996

English Version

Steel sheet and strip for welded gas cylinders

Tôles et bandes pour bouteilles à gaz soudées en acier Stahlblech und -band für geschweißte Gasflaschen

This European Standard was approved by CEN on 1 August 2008.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the CEN Management Centre or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the
official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 10120:2008: E
worldwide for CEN national Members.
BS EN 10120:2008
EN 10120:2008 (E)

Contents Page

Foreword..............................................................................................................................................................3
1 Scope ......................................................................................................................................................4
2 Normative references ............................................................................................................................4
3 Terms and definitions ...........................................................................................................................4
4 Classification and designation.............................................................................................................5
5 Information to be supplied by the purchaser .....................................................................................5
5.1 Mandatory information ..........................................................................................................................5
5.2 Options ...................................................................................................................................................5
5.3 Example of ordering ..............................................................................................................................6
6 Manufacturing process .........................................................................................................................6
6.1 Steelmaking process .............................................................................................................................6
6.2 Delivery condition..................................................................................................................................6
7 Requirements .........................................................................................................................................6
7.1 Chemical composition ..........................................................................................................................6
7.2 Mechanical properties ...........................................................................................................................7
7.3 Weldability ..............................................................................................................................................8
7.4 Tolerances ..............................................................................................................................................8
7.5 Surface condition...................................................................................................................................8
8 Inspection ...............................................................................................................................................8
8.1 Types of inspection and inspection documents ................................................................................8
8.2 Tests to be carried out ..........................................................................................................................9
8.3 Retests, sorting and reprocessing.......................................................................................................9
9 Sampling.................................................................................................................................................9
9.1 Frequency of testing .............................................................................................................................9
9.2 Sampling and test piece preparation...................................................................................................9
10 Test methods........................................................................................................................................10
10.1 Chemical analysis................................................................................................................................10
10.2 Tensile test ...........................................................................................................................................10
10.3 Other testing.........................................................................................................................................10
11 Marking .................................................................................................................................................10

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 BS EN 10120:2008
EN 10120:2008 (E)

Foreword
This document (EN 10120:2008) has been prepared by Technical Committee ECISS/TC 22 “Steels for
pressure purposes - Qualities”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by March 2009, and conflicting national standards shall be withdrawn at
the latest by March 2009.

This document supersedes EN 10120:1996.

NOTE The clauses marked with a point (•) contain information relating to agreements which are to be made at the time
of enquiry and order. The clauses marked by two points (••) contain information relating to agreements that may be made
at the time of enquiry and order.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

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BS EN 10120:2008
EN 10120:2008 (E)

1 Scope
This European Standard specifies requirements for hot-rolled sheet and strip up to 5 mm thickness of steels
listed in Table 1 and intended for the manufacture of welded gas cylinders.

The general technical delivery conditions in EN 10021 also apply to products supplied in accordance with this
European Standard.

2 Normative references
The following referenced documents are indispensable for the application 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.

EN 10002-1:2001, Metallic materials — Tensile testing — Part 1: Method of test at ambient temperature

EN 10020:2000, Definition and classification of grades of steel

EN 10021, General technical delivery conditions for steel products

EN 10027-1, Designation systems for steels — Part 1: Steel names

EN 10027-2, Designation systems for steels — Part 2: Numerical system

EN 10051, Continuously hot rolled uncoated plate, sheet and strip of non-alloy and alloy steels — Tolerances
on dimensions and shape

EN 10052:1993, Vocabulary of heat treatment terms for ferrous products

EN 10079:2007, Definition of steel products

EN 10168, Steel products — Inspection documents — List of information and description

EN 10204, Metallic products — Types of inspection documents

CEN/TR 10261, Iron and steel ― Review of available methods of chemical analysis

EN ISO 377, Steel and steel products — Location and preparation of samples and test pieces for mechanical
testing (ISO 377:1997)

EN ISO 2566-1, Steel — Conversion of elongation values — Part 1: Carbon and low alloy steels (ISO 2566-
1:1984)

EN ISO 14284, Steel and iron — Sampling and preparation of samples for the determination of chemical
composition (ISO 14284:1996)

3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 10020:2000, EN 10052:1993 (but
see 3.1), EN 10079:2007 and the following apply.

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 BS EN 10120:2008
EN 10120:2008 (E)

3.1
normalizing rolling [deviating from EN 10052:1993]

rolling process in which the final deformation process is carried out in a certain temperature range leading to a
material condition equivalent to that obtained after normalizing so that the specified values of the mechanical
properties are retained even after normalizing

NOTE The symbol for this delivery condition is N.

4 Classification and designation

4.1 Classification

The steels specified in this European Standard are non-alloy quality steels in accordance with EN 10020.

4.2 Designation

The steel grades are designated with steel names in accordance with EN 10027-1. The corresponding steel
numbers have been allocated in accordance with EN 10027-2.

5 Information to be supplied by the purchaser

5.1 Mandatory information

The following information shall be supplied by the purchaser at the time of enquiry and order:

a) quantity required;

b) type of flat products (sheet or strip);

c) nominal dimensions of the product (length1), width, thickness);

d) number of this European Standard;

e) steel name or number (see Table 1 or 3);

f) delivery condition (see 6.2 and 7.5);

g) inspection document to be delivered (see 8.1.1).

5.2 Options

A number of options are specified in this European Standard and listed below. If the purchaser does not
indicate his wish to implement any of these options the products shall be supplied in accordance with the
basic specification (see 5.1).

1) Information on the melting and deoxidation process (see 6.1.1 and 6.1.2)

2) Product analysis (see 7.1.2 and Table 4)

3) Sampling conditions for the product analysis (see 9.2.2)

1) For sheet only

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BS EN 10120:2008
EN 10120:2008 (E)

4) Special marking conditions (see Clause 11)

5.3 Example of ordering

10 t sheets with nominal dimensions of thickness = 4,0 mm, width = 600 mm, length = 1 200 mm, made of the
steel grade P265NB (1.0423) as specified in EN 10120, delivered normalized, descaled and oiled, inspection
certificate 3.1 in accordance with EN 10204:

10 t sheet – 600x1200x4,0 – EN 10120 – P265NB– normalized and oiled – EN 10204-3.1

or
10 t sheet – 600x1200x4,0 – EN 10120 – 1.0423– normalized and oiled – EN 10204-3.1

6 Manufacturing process

6.1 Steelmaking process

6.1.1 ●● The melting and deoxidation process shall be at the discretion of the manufacturer with the
limitations to 6.1.2 and 6.1.3 and Table 1, unless otherwise agreed at the time of enquiry and order.

6.1.2 ●● The steel shall be manufactured using the electric arc process or an oxygen process. Other
melting processes may be used by agreement at the time of enquiry and order. On request, the purchaser
shall be informed of the process used.

6.1.3 The used type of deoxidation shall ensure that the steel has an acceptable degree of resistance to
ageing (see Table 1, footnote b).

6.2 Delivery condition

● The delivery condition shall be specified at the time of enquiry and order. Usual delivery conditions are:

a) hot rolled and normalized (N)2) ;

b) hot rolled (AR).

2)
NOTE The delivery condition "hot rolled and normalized " is generally used for gas cylinders which are only stress
relieved after welding. The "hot rolled" delivery condition is only intended for gas cylinders which are normalized after
welding.

7 Requirements

7.1 Chemical composition

7.1.1 Cast analysis

The cast analysis reported by the steel producer shall apply and comply with the requirements of Table 1.

7.1.2 Product analysis

The product analysis shall not deviate from the limiting values for the cast analysis as specified in Table 1 by
more than the values given in Table 2.

2) This includes the normalizing rolled condition.

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 BS EN 10120:2008
EN 10120:2008 (E)

a
Table 1 — Chemical composition of the cast analysis, in %
Steel grade C Si Mn P S Altotalb Nc Nb Ti
Steel Steel max. max. min. max. max. min. max. max. max.
name number

P245NB 1.0111 0,16 0,25 0,30 0,025 0,015 0,020 0,009 0,050 0,03
P265NB 1.0423 0,19 0,25 0,40 0,025 0,015 0,020 0,009 0,050 0,03
P310NB 1.0437 0,20 0,50 0,70 0,025 0,015 0,020 0,009 0,050 0,03

P355NB 1.0557 0,20 0,50 0,70 0,025 0,015 0,020 0,009 0,050 0,03
a Elements not listed in this table may not be intentionally added to the steel without the agreement of the purchaser except for
finishing the cast. All appropriate measures shall be taken to prevent the addition from scrap or other materials used in steelmaking
of these elements which may adversely affect the mechanical properties and usability.
b The aluminium content may partly be replaced by ≤ 0,050 % Nb and/or ≤ 0,03 % Ti (see 6.1.3). In such cases the content of these
elements is to be reported in the inspection document.

c Al total
If the ratio of ≥ 2,2 or if Nb and/or Ti additions are applied, the nitrogen content may be ≤ 0,012 %.
N

Table 2 – Permissible product analysis tolerances on the limiting values given in Table 1 for the cast
analysis
Limiting value of the cast Permissible deviation of the
Element
analysis product analysis

C ≤ 0,20 + 0,02
Si ≤ 0,50 + 0,05
Mn ≥ 0,30 – 0,05
P ≤ 0,025 + 0,005
S ≤ 0,015 + 0,003
Altotal ≥ 0,020 – 0,005
N ≤ 0,009 + 0,002
Nb ≤ 0,050 + 0,010
Ti ≤ 0, 03 + 0,01

7.2 Mechanical properties

The mechanical properties shall comply with the values in Table 3 which are applicable to samples in the
normalized or normalizing rolled condition.

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BS EN 10120:2008
EN 10120:2008 (E)

a
Table 3 – Mechanical properties and guidance for heat treatment
Steel grade Upper yield Tensile Elongation after fracture Normalizing
strength strength A temperature
(for guidance)b
ReH Rm min.
for product thickness t in mm
min.
Steel name Steel number t<3 3≤t≤5
(LO = 80 mm)
(LO = 5,65 So ) °C
MPa MPa
% %
P245NB 1.0111 245 360 to 450 26 34 900 to 940

P265NB 1.0423 265 410 to 500 24 32 890 to 930

P310NB 1.0437 310 460 to 550 21 28 890 to 930
P355NB 1.0557 355 510 to 620 19 24 880 to 920

a See also 7.2 and 9.2.3.

b The normalizing temperatures given here are only mandatory if reference test pieces are to be tested.

7.3 Weldability

The steels in accordance with this European Standard are weldable using the usual fusion welding processes.

7.4 Tolerances

Tolerances on dimensions and mass shall be in accordance with EN 10051.

7.5 Surface condition

● Depending on the specified surface condition, the sheet or strip shall be supplied either in the rolled
condition or in the chemically or mechanically descaled and oiled condition.

External imperfections which do not impair the intended application shall not be the cause of rejection. Only
the material involved can be rejected on the basis of external defects.

8 Inspection

8.1 Types of inspection and inspection documents

8.1.1 The compliance with the requirements of the order shall be checked for products in accordance with
this European Standard by specific inspection.

● The purchaser shall state the required type of inspection document (3.1 or 3.2) in accordance with
EN 10204.

If an inspection document 3.2 is specified, the purchaser shall notify the manufacturer of the name and
address of the organization or person who is to carry out the inspection and produce the inspection document.
It shall be agreed which party shall issue the certificate.

8.1.2 The inspection document shall include, in accordance with EN 10168, the following codes and
information:

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 BS EN 10120:2008
EN 10120:2008 (E)

A Commercial transactions and parties involved;

B Description of products to which the inspection certificate applies;

C03 Test temperature;

C10-C13 Tensile test at room temperature;

C70 Steelmaking process, if applicable;

C71-C92 Cast analysis and, if applicable, product analysis;

D01 Marking, dimensional and visual inspection;

Z Validation.

8.2 Tests to be carried out

The mandatory and optional tests to be carried out, the size of the test units, and the number of samples and
test pieces to be taken are specified in 10.1 and Table 4.

Table 4 – Summary of tests and extent of testing

Type of inspection and test Test frequencya Refer to

Cast analysis 1 per cast 7.1.1

Mandatory
Tensile test 1 per sample 9.1, 9.2 and 10.2
tests
Dimensional and visual inspection Each product 10.3.1 and 10.3.2

Optional tests Product analysis 1 per cast 9.1, 9.2 and 10.1
a For sampling and size of test units, see 9.1 and 9.2.1.

8.3 Retests, sorting and reprocessing

For retests, sorting and reprocessing the requirements of EN 10021 shall apply.

9 Sampling

9.1 Frequency of testing

9.1.1 The tests shall be carried out by cast.

9.1.2 The inspection unit shall be 40 t or the remaining fraction. However, a maximum of 4 samples per cast
shall be tested.

9.2 Sampling and test piece preparation

9.2.1 Sampling and test piece preparation shall be in accordance with the requirements of EN ISO 14284
and EN ISO 377.

9.2.2 ●● Unless otherwise agreed at the time of enquiry and order, the sample for the product analysis may
be taken from the samples for the tensile test.

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BS EN 10120:2008
EN 10120:2008 (E)

9.2.3 The test samples for the tensile test shall be taken at 1/4 product width from the rolled edge. In the
case of strip, the test samples shall be taken from the outer end; in cases of dispute, it shall be taken at an
adequate distance from the outer end (at least one turn). The longitudinal axis of the test piece shall be
perpendicular to the (final) rolling direction. If products are delivered in a condition other than the normalized
or normalizing rolled condition (see 6.2 b)), the test samples or test pieces shall be normalized.

For thicknesses ≥ 3 mm, test pieces in accordance with EN 10002-1 shall be prepared. The test piece shall
include both rolled surfaces. Except in the case of dispute, non-proportional test pieces may be also used (see
10.2).

10 Test methods

10.1 Chemical analysis

●● Unless otherwise agreed at the time of enquiry and order, the choice of a suitable physical or chemical
analytical method for the product analysis shall be at the discretion of the manufacturer. In cases of dispute,
the analysis shall be carried out by a laboratory approved by both parties. In this case, the analysis method to
be used shall be agreed taking into account the relevant existing European Standards. The list of available
European Standards is given in CEN/TR 10261.

10.2 Tensile test

The tensile test shall be carried out in accordance with EN 10002-1 at (23 ± 5) °C, generally using a
proportional test piece of gauge length (LO = 5,65 So ), where So is the initial cross-sectional area of the test
piece. Test pieces with a constant gauge length may be used; in this case the elongation value shall be
converted in accordance with EN ISO 2566-1. In the case of flat products less than 3 mm thick, the tensile test
in accordance with EN 10002-1:2001, Annex B, using an original gauge length of 80 mm shall be applied.

The tensile strength Rm, upper yield strength ReH and elongation A shall be determined.

10.3 Other testing

10.3.1 The dimensions of the products shall be checked.

10.3.2 The surface condition of the products shall be checked for conformity with 7.5 by visual examination
without optical aids or, at the discretion of the manufacturer, by an approved automated process.

11 Marking
●● Unless otherwise agreed at the time of enquiry and order, the products shall be marked with labels. The
marking shall contain the following information:

a) mark of the manufacturer;

b) designation of the steel grade;

c) cast number;

d) strip number;

e) inspector's mark;

f) identification number which permits the correlation of the delivery unit with the related inspection
document.

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 BS EN 10120:2008

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BS EN
10120:2008
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