GB/T 232-2024Metallic materials - Bend testing method (English PDF)

Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020

Directives for standardization - Part 1.Rules for the structure and drafting of

standardizing documents.

This document replaces GB/T 232-2010 Metallic materials - Bend test. Compared with

GB/T 232-2010, in addition to structural adjustments and editorial changes, the main

technical changes are as follows.

-- Figure 3 is changed (see Figure 3; see Figure 3 of the 2010 edition);

-- Requirements for test piece plane strain conditions are added (see 7.3);

-- Requirements for test pieces of forged materials, cast materials and semi-finished

products are changed (see 7.5; see 6.5 of the 2010 edition);

-- Some symbols and descriptions are changed; and the Lode angle parameter ,

stress triaxiality eta and radius of supports R are added (see Table 1; see Table 1

of the 2010 edition);

-- A description of the bending test under plane strain conditions is added (see

Appendix A).

This document was modified in relation to ISO 7438.2020 Metallic materials - Bend

test.

Compared with ISO 7438.2020, the following structural adjustments are made in this

document.

-- 8.3 of ISO 7438.2020 is divided into 8.3 and 8.4, and 8.4 of ISO 7438.2020 is

postponed to 8.5;

-- The order of Appendix A and Appendix B is exchanged.

The technical differences between this document and ISO 7438.2020 and their reasons

are as follows.

-- The content "other bending devices that comply with the bending test principle

can be used" is added (see 6.5), and the turning-plate bending device is retained,

to meet Chinese national conditions;

-- The normative reference document GB/T 2975 is added (see 7.1) to ensure the

operability of the standard;

-- The "inner radius" is changed to "diameter of the former" (see 9.2) for better

operability;

-- The "square root of eta" is changed to "eta value" (see A.2) to keep it consistent with

the previous sentence.

The following editorial changes are made to this document.

-- The name of the standard is changed to "Metallic materials - Bend testing

method";

-- The reference to Figure 5 is added [see 8.2 a)].

Please note that some content in this document may be subject to patents. The publisher

of this document assumes no responsibility for identifying patents.

This document was proposed by the China Iron and Steel Association.

This document is under the jurisdiction of the National Technical Committee on Steel

of Standardization Administration of China (SAC/TC183).

Drafting organizations of this document. Shougang Group Co., Ltd., Zhejiang Kingland

Pipe Industry Co., Ltd., Rizhao Quality Inspection and Testing Institute [National

Carbon Structural Steel Product Quality Inspection and Testing Center (Shandong)],

Tongling Fuxin Iron and Steel Co., Ltd., Hunan Valin Xiangtan Iron and Steel Co., Ltd.,

Jiangsu Chengxin Inspection, Testing and Certification Co., Ltd., Ningxia Jianlong

Special Steel Co., Ltd., Inner Mongolia Baotou Steel Union Co., Ltd., Jianlong Xilin

Iron and Steel Co., Ltd., Shandong Xindadi Holding Group Co., Ltd., Zhejiang

Academy of Special Equipment Science, Shenzhen SUNS Technology Stock Co., Ltd.,

Jilin Jianlong Steel Co., Ltd., Shandong Special Equipment Inspection Institute Group

Co., Ltd., China Metallurgical Information and Standardization Institute, Wuhan

Fanzhou Chuetsu Metal Co., Ltd.

Main drafters of this document. Qiu Yu, Yang Weifang, Lu Xianbao, Ding Gang, Kuang

Yonghai, Zou Fanqiu, Gan Meilu, Wang Shifeng, Ma Yue, Xu Weili, Fu Chongjian,

Cheng Dongyue, Liu Jie, Zhao Junqing, Yao Xiaojing, Dong Li, Yao Lian, Zhang

Qingshui, Ni Guoliang, Cui Lei, Hou Huining, Zhang Xing, Su Zan, Wang Shuqiang,

Wang Bin, Wang Shangkun, Sun Dayong, Liu Zhongqiang, Zhang Haihua, Wang

Chunmao, Li Qiuhan, Zhang Qi, Mou Xueping, Zhang Qiang, Zhou Zhichao, Wu

Chaohui, Wang Wei.

This document was first published in 1963, revised for the first time in 1982, for the

second time in 1988, for the third time in 1999, and for the fourth time in 2010.This is

the fifth revision.

Metallic materials - Bend testing method

1 Scope

This document describes a test method for determining the ability of metallic materials

to withstand plastic deformation in bending.

This document is applicable to the bending test of test pieces specified in product

standards related to metal materials.

2 Normative references

The contents of the following documents constitute essential provisions of this

document through normative references in the text. Among them, for referenced

documents with a date, only the version corresponding to the date is applicable to this

document. For undated referenced documents, the latest version (including all

amendments) applies to this document.

GB/T 2975 Steel and steel products - Location and preparation of samples and test

pieces for mechanical testing (GB/T 2975-2018, ISO 377.2017, MOD)

3 Terms and definitions

There are no terms or definitions that need to be defined in this document.

4 Symbols and descriptions

The symbols and descriptions used in this document are shown in Table 1.

5 Principles

The bending test is to subject a circular, square, rectangular or polygonal cross-section

test piece to bending plastic deformation on a bending device without changing the

direction of force until the specified bending angle is reached.

6 Test equipment

The angle of the tapered surface of the V-block shall be 180°-alpha (see Figure 2), and the

bending angle alpha shall be specified in the relevant product standards.

The device consists of a clamp and a bending former with sufficient hardness (see

Figure 3), and can be equipped with a force lever.

Other bending devices that comply with the bending test principle (such as a turning-

plate bending device) can also be used.

7 Test pieces

The width of the test piece shall comply with the provisions of the relevant product

standards. If no specific provisions are given, the following requirements shall apply.

By agreement, test pieces with a width greater than that specified in 7.3 and a thickness

greater than that specified in 7.4 may be used for the bending test.

The length of the test piece shall be determined based on the thickness (or diameter) of

the test piece and the test equipment used.

8 Test procedures

WARNING. Adequate safety measures and protective equipment shall be taken

during the test.

9 Evaluation of test results

The bending test results shall be evaluated in accordance with the requirements of

the relevant product standards.

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