ISO 23721:2022 金属および合金の腐食 - ステンレス鋼の大気腐食の錆および汚れの出現による評価方法 | ページ 2

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 156, Corrosion of metals and alloys.

Introduction

Stainless steels contain at least 10,5 % Cr and are widely used in domestic electric utilities, kitchen utensils, transportation vehicles, and industrial plants. Corrosion-resistant stainless steels are also used as architectural materials, e.g. exterior parts and roofs of buildings. Furthermore, stainless steels are used as braid materials for automotive parts.

Corrosion loss and pitting depth are important factors for selecting, deciding the thickness and estimating the lifetime of materials. Aesthetic appearance is also important for stainless steels used in exterior parts. Therefore, a method for evaluating the appearance of stainless steels under atmospheric exposure is required.

1 Scope

This document specifies a method for evaluating the aesthetic appearance of stainless steels qualitatively by rating rust and stains formed by atmospheric corrosion. The rust and stains on stainless steels formed by atmospheric corrosion are rated by using 10 photographic standards.

This method is especially suitable for evaluating the appearance of specimens and structures made of stainless steels under atmosphere exposure.

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.

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 8044 and the following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

Bibliography