ISO 15208:2022

Continuous hot-dip zinc-coated twin-roll cast steel sheet of commercial quality

This document specifies the requirements for steel sheet, in coils and cut length, metallic-coated by the continuous hot-dip zinc-coated twin-roll cast process of commercial quality. The steel sheet is intended for applications requiring corrosion resistance, formability and paintability. The steel sheet is produced in a number of grades, coating masses, surface treatments and ordering conditions.

Tôles coulées entre cylindres et galvanisées en continu par immersion à chaud, en acier de qualité commerciale

General Information

• Status: Published
• Publication Date: 27-Feb-2022
• ICS: 77.140.50 - Flat steel products and semi-products
• Technical Committee: ISO/TC 17/SC 12 - Continuous mill flat rolled products
• Drafting Committee: ISO/TC 17/SC 12 - Continuous mill flat rolled products
• Current Stage: 6060 - International Standard published
• Start Date: 28-Feb-2022
• Due Date: 26-Oct-2021
• Completion Date: 28-Feb-2022

Relations

• Revises: ISO 15208:2012 - Continuous hot-dip zinc-coated twin-roll cast steel sheet of commercial quality
• Effective Date: 11-Nov-2017

Overview

ISO 15208:2022 - "Continuous hot-dip zinc-coated twin-roll cast steel sheet of commercial quality" - specifies requirements for steel sheet produced by the continuous hot‑dip zinc coating process applied to twin‑roll cast strip. It covers products supplied in coils and cut lengths, intended for applications needing corrosion resistance, formability and paintability. The standard defines grades, coating masses, surface finishes and ordering conditions for commercial‑quality twin‑roll cast zinc‑coated steel.

Key topics and technical requirements

• Dimensions and product form
  • Sheet thicknesses up to 2.0 mm (after coating) and widths up to 2 000 mm; sheets less than 600 mm slit from wide sheet treated as sheet.
  • Thickness may be specified as base‑metal only or base‑metal plus coating (purchaser must state preference).
• Manufacture and chemical control
  • Requirements for steelmaking, chemical composition and both heat and product analyses.
• Mechanical properties and testing
  • Tensile testing (room temperature) and bend tests referenced; sampling and retest provisions defined.
• Coating requirements
  • Coating mass expressed in g/m2 (total both surfaces), coating adherence and use of differential coatings (different masses on each side).
  • Surface finishes: normal spangle, minimized spangle, and skin pass options.
• Surface treatments and paintability
  • Mill passivation, mill phosphating and oiling requirements to support painting and forming.
• Weldability and coated coil joining
  • Guidance on suitability for welding and methods to join coated coils.
• Dimensional and shape tolerances, inspection and acceptance
  • Sampling methods, test methods and designation/marking systems; provisions for workmanship, retests and resubmission.

Practical applications and users

ISO 15208:2022 is used by:

• Steel producers and continuous coating line operators to specify production, coating mass and surface finish.
• Purchasers, specifiers and procurement teams in construction, automotive components, white goods, roofing and general industrial fabrication who need corrosion‑resistant, formable, paintable sheet.
• Fabricators and paintshops requiring defined surface pretreatments (phosphating, passivation) and formability/weldability data.
• Quality, testing and inspection laboratories for sampling, tensile and coating tests to verify compliance.

Typical applications include painted panels, formed components, exterior cladding, appliance housings and other moderately formed or flat-sheet uses where durability and paint adhesion are important.

Related standards

ISO 15208 references several normative standards for tests and measurements, including:

• ISO 1460 (gravimetric coating mass)
• ISO 2178, ISO 3497 (coating thickness measurement)
• ISO 6892‑1 (tensile testing)
• ISO 7438 (bend test)
• ISO 16163 (dimensional and shape tolerances)

For specification, procurement or compliance, consult the full ISO 15208:2022 document and the referenced ISO test standards for complete technical details.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 15208
Second edition
2022-02
Continuous hot-dip zinc-coated twin-
roll cast steel sheet of commercial
quality
Tôles coulées entre cylindres et galvanisées en continu par immersion
à chaud, en acier de qualité commerciale
Reference number
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
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
5.5 Coating . 4
5.5.1 Coating mass . 4
5.5.2 Coating adherence. 4
5.6 Weldability . 5
5.7 Painting . 5
5.8 Surface treatment . 5
5.8.1 Mill passivation . 5
5.8.2 Mill phosphating . 5
5.8.3 Oiling . 5
5.9 Coated coil joining . 6
5.10 Dimensional and shape tolerances . 6
6 Sampling . 6
6.1 Tensile test . 6
6.2 Coating tests . 6
6.2.1 Coating mass . 6
6.2.2 Triple-spot test . 6
6.2.3 Single-spot test . 6
6.2.4 Coating adherence. 6
7 Test methods . 7
7.1 Tensile test . 7
7.2 Coating properties. 7
7.2.1 Coating mass . 7
7.2.2 Coating adherence. 7
8 Designation system . 7
8.1 General . 7
8.2 Coating type . 7
8.3 Coating mass . 7
8.4 Coating finish condition . 8
8.5 Surface treatment . 8
8.6 Base-metal quality . 8
8.7 Examples . 8
9 Retests . 9
9.1 Machining and flaws . . 9
9.2 Elongation . 9
9.3 Additional tests . 9
10 Resubmission. 9
11 Workmanship . 9
12 Inspection and acceptance .9
iii
13 Coil Size .10
14 Marking . .10
15 Information supplied by the purchaser .10
Annex A (normative) Orders requiring base-metal thickness .12
Bibliography .13
iv
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 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 12, Continuous
mill flat rolled products.
This second edition cancels and replaces the first edition (ISO 15208:2012), which has been technically
revised.
The main changes are as follows:
— editorial update;
— update of Clause 3;
— modification of the title of Clause 4.
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.
v
INTERNATIONAL STANDARD ISO 15208:2022(E)
Continuous hot-dip zinc-coated twin-roll cast steel sheet of
commercial quality
1 Scope
This document specifies the requirements for steel sheet, in coils and cut length, metallic-coated by the
continuous hot-dip zinc-coated twin-roll cast process of commercial quality.
The steel sheet is intended for applications requiring corrosion resistance, formability and paintability.
The steel sheet is produced in a number of grades, coating masses, surface treatments and ordering
conditions.
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 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
commercial quality
base-metal quality intended for general fabricating purposes where sheet is used in the flat condition,
or for bending or moderate forming
3.2
continuous hot-dip zinc-coated steel sheet
product in coils or cut lengths manufactured on a continuous coating line with a hot-dip zinc coating on
base-metal of cold-reduced or hot-rolled descaled steel
3.3
normal spangle
finish obtained as a result of unrestricted growth of zinc crystals during normal solidification
Note 1 to entry: This coating has a metallic lustre and is the type normally furnished for a wide variety of
applications. It can be furnished S (normal spangle with skin pass) or N (normal spangle, no skin pass), however,
it can be variable in appearance and not suitable for decorative paintings.
3.4
minimized spangle
finish obtained by restricting normal spangle formation during the solidification of the zinc
Note 1 to entry: This product can have some lack of uniformity in surface appearance within a coil or from coil to
coil.
3.5
differential coating
coating deliberately produced to have a different coating mass on each surface
3.6
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 or to obtain the required surface finish.
Note 2 to entry: Some increase in hardness and some loss in ductility will result from skin passing.
3.7
twin-roll cast steel sheet
steel sheet produced by casting to near final thickness directly from the liquid metal with minimal hot-
rolling to achieve the final thickness
3.8
lot
up to a specified quantity of steel sheet of the same designation rolled to the same thickness and coating
condition
3.9
coating mass
total amount of zinc on both surfaces of the sheet, expressed in grams per square meter (g/m ) of sheet
4 Dimensions
4.1 Zinc-coated commercial quality twin-roll cast steel sheet is produced in thicknesses up to 2,0 mm,
inclusive, after zinc coating, and in widths up to 2 000 mm in coils and cut lengths. Zinc-coated twin-
roll cast steel sheet less than 600 mm wide, slit from wide sheet, is considered as sheet.
4.2 The thickness of zinc-coated twin-roll cast steel sheet may be specified as a combination of the
base-metal and metallic coating or base-metal alone. The purchaser shall indicate on the order which
method of specifying thickness is required. If the purchaser does not indicate any preference, the
thickness as a combination of the base-metal and coating shall 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
...