GB/T 41116-2021Non-destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptance levels (English PDF)

Foreword

This document is drafted in accordance with GB/T 1.1-2020 "Directives for

standardization - Part 1: Rules for the structure and drafting of standardizing

documents".

This document, using translation method, is identical to ISO 15626:2018 "Non-

destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptance

levels".

China's document which has a consistent correspondence with the international

document normatively referenced in this document is as follows:

- GB/T 12604.1-2020 Non-destructive testing - Terminology - Ultrasonic testing

(ISO 5577:2017, MOD)

The following editorial change has been made to this document:

- Add footnotes (Clause 5).

Attention is drawn to the possibility that some of the elements of this document may be

the subject of patent rights. The issuing authority of this document shall not be held

responsible for identifying any or all such patent rights.

This document was proposed by China Machinery Industry Federation.

This document shall be under the jurisdiction of National Technical Committee 55 on

Welding of Standardization Administration of China (SAC/TC 55).

Drafting organizations of this document: Shanghai Research Institute of Materials,

Guangzhou Special Pressure Equipment Inspection and Research Institute, Jiangsu

Shengyang Fire Door Industry Co., Ltd., Jiangsu Frontier Electric Technology Co., Ltd.,

Shanghai Ship Engineering Quality Testing Co., Ltd., Zhejiang Kingland Pipeline &

Technologies Co., Ltd., Beijing Zouzhan Lucheng Science and Technology Co., Ltd.,

Harbin Welding Institute Co., Ltd.

Main drafters of this document: Ding Jie, Jiang Jiansheng, Li Maodong, Huang Yin,

Ma Junpeng, Zhou Changzhi, Wang Lili, Wang Bin, Zhang Zaidong, Li Jianfeng, Zhai

Lianna, Liu Jing, Su Jinhua, Ding Bing, Xiong Junbo.

Non-destructive testing of welds - Time-of-flight diffraction

technique (TOFD) - Acceptance levels

1 Scope

This document specifies acceptance levels for the time-of-flight diffraction technique

(TOFD) of full penetration welds in ferritic steels from 6 mm up to 300 mm thickness

which correspond to the quality levels of ISO 5817.

The acceptance levels specified in this document are applicable to indications classified

in accordance with ISO 10863.

2 Normative references

The contents of the following documents, through normative references in this text,

constitute indispensable provisions of this document. Among them, for dated references,

only the edition corresponding to that date applies to this document. For undated

references, the latest edition (including all amendments) applies to this document.

ISO 5577 Non-destructive testing - Ultrasonic testing - Vocabulary

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5577 and the

following apply.

ISO and IEC maintain terminological databases for use in standardization at the

following addresses:

- IEC Electropedia: http://www.electropedia.org/;

- ISO Online browsing platform: https://www.iso.org/obp.

3.1

Embedded discontinuity

Discontinuity within the volume of the material, separated from the surfaces.

3.2

Surface-breaking discontinuity

Discontinuity connected to the scanning surface or bottom surface (opposite to the

scanning surface).

4 Symbols

For the purposes of this document, the following symbols apply.

h - height of an indication

l - length of an indication

t - nominal thickness of workpiece under test in accordance with construction

drawing or dimension table

5 Relation between quality levels and acceptance levels

Three different acceptance levels (levels 1, 2, and 3) are defined in this document. The

relation between these acceptance levels and the quality levels as mentioned in ISO

5817 are given in Table 1.

6 Length and height of an indication