ISO 9364:2017

INTERNATIONAL ISO
STANDARD 9364
Fifth edition
2017-11
Steel sheet, 55 % aluminium-zinc
alloy-coated by the continuous hot-dip
process, of commercial, drawing and
structural qualities
Tôles en acier revêtues en continu par immersion à chaud d'une
couche d'alliage aluminium-zinc 55 % de qualité commerciale, pour
emboutissage ou destinées à la construction
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Dimensions . 2
5 Conditions of manufacture . 3
5.1 Steelmaking . 3
5.2 Chemical composition . 3
5.3 Chemical analysis . 3
5.3.1 Heat analysis . . 3
5.3.2 Product analysis . 3
5.4 Mechanical properties . 4
5.4.1 Commercial and drawing quality . 4
5.4.2 Structural quality . . 5
5.5 Coating . 6
5.5.1 Coating mass. 6
5.5.2 Coating adherence . 7
5.6 Weldability . 7
5.7 Painting . 7
5.8 Coating finish condition . 7
5.9 Surface treatment . 8
5.9.1 Mill passivation . 8
5.9.2 Oiling . 8
5.10 Coated coil joining . 8
5.11 Dimensional and shape tolerances . 8
6 Sampling . 8
6.1 Tensile test . 8
6.2 Coating tests . 8
6.2.1 Coating mass. 8
6.2.2 Triple-spot test . 8
6.2.3 Single-spot test . 9
6.2.4 Coating adherence . 9
7 Test methods . 9
7.1 Tensile test . 9
7.2 Coating properties . 9
7.2.1 Coating mass. 9
7.2.2 Coating adherence . 9
8 Designation system . 9
8.1 General . 9
8.2 Coating designation . 9
8.3 Coating mass .10
8.4 Coating finish condition .10
8.5 Surface treatment .10
8.6 Base-metal quality .10
8.7 Examples .10
9 Retests .11
9.1 Machining and flaws.11
9.2 Elongation .11
9.3 Additional tests .11
10 Resubmission .11
11 Workmanship .12
12 Inspection and acceptance .12
13 Coil size .12
14 Marking .12
15 Information to be supplied by the purchaser.13
Annex A (normative) Orders requiring base-metal thickness .14
Bibliography .15
iv © ISO 2017 – All rights reserved

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
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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
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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 12, Continuous
mill flat rolled products.
This fifth edition cancels and replaces the fourth edition (ISO 9364:2011), which has been technically
revised.
INTERNATIONAL STANDARD ISO 9364:2017(E)
Steel sheet, 55 % aluminium-zinc alloy-coated by the
continuous hot-dip process, of commercial, drawing and
structural qualities
1 Scope
This document is applicable to the requirements for steel sheet, in coils and cut lengths, metallic-coated
by the continuous hot-dip process with 55 % aluminium-zinc alloy coating.
The product is intended for applications requiring the corrosion characteristics of aluminium coupled
with those of zinc, or heat resistance, or both.
The steel sheet is produced in a number of quality designations and grades, coating mass, surface
treatments and coating finish conditions designed to be compatible with differing application
requirements.
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 1460, Metallic coatings — Hot dip galvanized coatings on ferrous materials — Gravimetric
determination of the mass per unit area
ISO 2178, Non-magnetic coatings on magnetic substrates — Measurement of coating thickness —
Magnetic method
ISO 3497, Metallic coatings — Measurement of coating thickness — X-ray spectrometric methods
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7438, Metallic materials — Bend test
ISO 16163, Continuously hot-dipped coated steel sheet products — Dimensional and shape tolerances
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
commercial
base-metal quality intended for general fabricating purposes where sheet is used in the flat condition,
or for bending or moderate forming
3.2
drawing
base-metal quality intended for parts where drawing or severe forming may be involved
3.3
deep drawing
base-metal quality intended for parts where severe forming or severe drawing (3.2) may be involved
3.4
interstitial-free steel
IF steel
extra-low-carbon steel in which all interstitial elements are stabilized with titanium and/or equivalent
elements
Note 1 to entry: Interstitial-free steel is sometimes referred to as “stabilized steel”.
3.5
breakage allowance
agreed upon level of acceptable die breakage not subject to claim
3.6
normal spangle
coating formed as a result of unrestricted growth of aluminium-zinc alloy crystals during normal
solidification
3.7
smooth finish
smoothness produced by skin passing (3.8) the coated material in order to achieve an improved surface
condition as compared with the normal as-coated product
3.8
skin pass
light cold rolling of the product
Note 1 to entry: The purpose of the skin passing is one or more of the following: to minimize the appearance of
coil breaks, stretcher strains and fluting; to control the shape; and to obtain the required surface finish.
Note 2 to entry: Some increase in hardness and some loss in ductility will result from skin passing.
3.9
differential coating
coating deliberately produced to have a different coating mass (3.11) on each surface
3.10
lot
up to a specified quantity of steel sheet of the same designation rolled to the same thickness and coating
condition
3.11
coating mass
total amount of coating on both sides of the sheet
Note 1 to entry: Coating mass is expressed in grams per square metre.
4 Dimensions
4.1 55 % aluminium-zinc alloy-coated steel sheet is produced in thicknesses from 0,25 mm to 5 mm
inclusive after coating, and in widths of 600 mm and over in coils and cut lengths. 55 % aluminium-zinc
alloy-coated steel sheet less than 600 mm wide, slit from wide sheet, is considered as sheet.
4.2 The thickness of 55 % aluminium-zinc alloy-coated steel sheet may be specified as a combination
of the base metal and metallic coating, or as the base metal alone. The purchaser shall indicate on the
order which method of specifying thickness is required. In the event that the purchaser does not indicate
2 © ISO 2017 – All rights reserved

any preference, the thickness as a combination of the base metal and coating will be provided. Annex A
describes the requirements for specifying the thickness as base metal alone.
5 Conditions of manufacture
5.1 Steelmaking
Unless otherwise agreed by the interested parties, the processes used in making the steel and
in manufacturing 55 % aluminium-zinc alloy-coated steel sheet are left to the discretion of the
manufacturer. On request, the purchaser shall be informed of the steelmaking process being used.
5.2 Chemical composition
The chemical composition (heat analysis) shall conform to the requirements given in Tables 1 and 2.
5.3 Chemical analysis
5.3.1 Heat analysis
An analysis of each heat shall be made by the manufacturer in order to determine compliance with the
requirements given in Tables 1 and 2. On request, a report of the heat analysis shall be made available
to the purchaser or the purchaser’s representative. Each of the elements listed in Tables 1 and 2
shall be included in the report of the heat analysis. When the amount of copper, nickel, chromium or
molybdenum present is less than 0,02 %, the analysis may be reported as “< 0,02 %”.
5.3.2 Product analysis
A product analysis may be made by the purchaser in order to verify the specified analysis of the product
and shall take into consideration any normal heterogeneity. The product analysis shall be in accordance
with Tables 2 and 3.
Table 1 — Chemical composition (heat analysis)
Mass fractions in percent
Base-metal quality C Mn P S
Designation Name
max. max. max. max.
01 Commercial 0,10 0,60 0,030 0,035
a
02 and 03 Drawing and deep drawing 0,06 0,50 0,020 0,025
b
220 to 550 Structural 0,25 1,15 0,05 0,035
a
Interstitial-free steel may be applied (see 5.4.1.3).
b
Grades 250 and 280: phosphorus – 0,10 % max. Grade 350: phosphorus – 0,20 % max.
Table 2 — Limits on additional chemical elements
Mass fractions in percent
a a a,b a,b c c,d c
Cu Ni Cr Mo Nb V Ti
Element
max. max. max. max. max. max. max.
Heat
0,20 0,20 0,15 0,06 0,008 0,008 0,008
analysis
Product
0,23 0,23 0,19 0,07 0,018 0,018 0,018
analysis
a
The sum of copper, nickel, chromium and molybdenum shall not exceed 0,50 % on heat analysis. When one or more of
these elements are specified, the sum does not apply, in which case, only the individual limits on the remaining elements apply.
b
The sum of chromium and molybdenum shall not exceed 0,16 % on heat analysis. When one or more of these elements
are specified, the sum does not apply, in which case, only the individual limits on the remaining elements apply.
c
For interstitial-free steels only, the value of 0,15 % maximum for titanium, and 0,10 % maximum for niobium and
vanadium are acceptable to ensure that the carbon and nitrogen are fully stabilized.
d
Heat analysis greater than 0,008 % may be supplied after agreement between the manufacturer and the purchaser.
Table 3 — Product analysis tolerances for Table 1
Mass fractions in percent
Maximum of specified Tolerance over maximum
Element
element specified
0,15 0,03
C
0,25 0,04
Mn 1,15 0,05
P 0,20 0,01
S 0,035 0,01
NOTE  The maximum tolerance is the allowable excess over the requirement of heat analysis shown in Table 1.
5.4 Mechanical properties
5.4.1 Commercial and drawing quality
5.4.1.1 Ordering conditions
55 % aluminium-zinc alloy-coated steel sheet of designations 02 and 03 are supplied under either of the
following two ordering conditions.
a) Ordering condition A: steel sheet mechanical properties shall, at the time the steel is made available
for shipment, satisfy the applicable
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