GB/T 26641-2021Non-destructive testing - Magnetic memory testing - General requirements (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 replaces GB/T 26641-2011 "Non-destructive testing - Magnetic

memory testing - General principles". Compared with GB/T 26641-2011, in addition to

structural adjustment and editorial changes, the main technical changes are as follows:

a) Modify the scope (see Clause 1; Clause 1 of the 2011 edition);

b) Modify and add normative references (see Clause 2; Clause 2 of the 2011 edition);

c) Modify and add terms (see Clause 3; Clause 3 of the 2011 edition);

d) Modify the method summary (see Clause 4; Clause 5 of the 2011 edition);

e) Modify the description of inspected object (see Clause 5; Clause 7 of the 2011

edition);

f) Modify the requirements for test equipment (see Clause 6; Clause 8 of the 2011

edition);

g) Modify the description of preparation for testing (see Clause 7; Clause 7 of the

2011 edition);

h) Modify the evaluation parameters and procedures; expand the previous normal

component or tangential component into a three-dimensional component (see 8.1;

Clause 10 of the 2011 edition);

i) Add the acquisition method and value criterion for gradient intermediate value and

gradient coefficient threshold (see 8.2 and 8.3);

j) Modify the test record and report (see Clause 9; Clause 11 of the 2011 edition);

k) Modify personnel qualification requirements (see Clause 10; Clause 4 of the 2011

edition).

This document is identical to ISO 24497-1:2020 "Non-destructive testing - Magnetic

memory testing - Part 1: Vocabulary and general requirements".

The following minimal editorial change has been made to this document:

- In order to harmonize with the existing standards, change the standard name to

"Non-destructive testing - Magnetic memory testing - General requirements".

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 and shall be under the jurisdiction of National

Technical Committee 56 on Non-destructive Testing of Standardization Administration

of China (SAC/TC 56).

Drafting organizations of this document: China Special Equipment Inspection and

Research Institute, Eddysun (Xiamen) Electronics Co., Ltd., Anhui Huaxia High

Science and Tech Development Co., Ltd., Tsinghua University, China Aerodynamics

Research and Development Center, Jiaxing Special Equipment Inspection and Testing

Institute, Chengdu University of Information Technology, Beijing University of

Technology, Central Research Institute of Building and Construction Co., Ltd.,

Shandong Kejie Engineering Testing Co., Ltd., Luoyang LYC Bearing Co., Ltd.

Main drafters of this document: Hu Bin, Wang Baoxuan, Shen Yongna, Shen Gongtian,

Lin Junming, Li Luming, Li Huan, Wei Dong, Pan Jinping, Hu Yun, Zhang Yiliang,

Gao Guangxing, Zhang Junjiao, Zhang Di, Liang Yumei, Chen Cuili.

The previous editions of this document and the documents it replaces are as follows:

- It was first issued as GB/T 26641-2011 in 2011. This is the first revision.

Non-destructive testing - Magnetic memory testing -

General requirements

1 Scope

This document specifies terms and definitions for non-destructive testing (NDT) by the

technique of metal magnetic memory (MMM) as well as general requirements for

application of this technique of the method.

This NDT technique specified in this document has the following objectives:

- determination of the heterogeneity of the magneto-mechanical state of

ferromagnetic objects, detection of defect stress concentration and boundaries of

metal microstructure heterogeneity;

- determination of locations with magnetic stray field aberrations for further

microstructural analysis and/or non-destructive testing and evaluation;

- early diagnostics of fatigue damage of the inspected object and evaluation of its

structural life time;

- quick sorting of new and used inspection objects by their magnetic heterogeneity

for further testing;

- efficiency improvement of non-destructive testing by combining magnetic memory

with other NDT methods or techniques (ultrasonic testing, x-ray, etc.) by fast

detection of the most probable defect locations;

- quality control of welded joints of various types and their embodiment (including

contact and spot welding). See ISO 24497-2 for details of this application.

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 9712 Non-destructive testing - Qualification and certification of personnel

Note: GB/T 9445-2015 Non-destructive testing - Qualification and certification of NDT

personnel (ISO 9712:2012, IDT)

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