GB/T 231.3-2022Metallic materials - Brinell hardness test - Part 3: Calibration of reference blocks (English PDF)

Foreword

This document was drafted in accordance with the rules provided in GB/T 1.1-2020

Directives for Standardization - Part 1: Rules for the Structure and Drafting of

Standardizing Documents.

This document is Part 3 of GB/T 231 Metallic materials - Brinell hardness test. The

following parts have been released for GB/T 231:

-- Part 1: Test method;

-- Part 2: Verification and calibration of testing machines;

-- Part 3: Calibration of reference blocks;

-- Part 4: Tables of hardness values.

This document replaces GB/T231.3-2012 Metallic materials - Brinell hardness test -

Part 3: Calibration of reference blocks; compared with GB/T 231.3-2012, the major

technical changes are as follows:

-- Change the test requirements for test force (see 5.4; 4.4 of the 2012 edition);

-- Change the measurement requirements of the indenters (see 5.5; 4.5 of the 2012

edition);

-- Change the performance requirements of the indentation diameter measurement

machine, and give the definition (see 5.6; 4.6 of the 2012 edition);

-- Delete the characteristic requirements of cemented carbide balls (see 4.8 of the

2012 edition);

-- Change the requirements for the maximum indenter approach velocity (see Clause

6, Table 3; Clause 5 of the 2012 edition);

-- Add the requirements for the reference indentation (see Clause 7);

-- Add the requirements for uncertainty content in the certificate [see 9.3d)];

-- Add a general for the evaluation of the uncertainty of measurement of the mean

hardness value of reference blocks (see A.1).

This document adopts the modification of ISO 6506-3:2014 Metallic materials - Brinell

hardness test - Part 3: Calibration of reference blocks.

There are technical differences between this document and ISO 6506-3:2014, and the

clauses involved in these differences have been marked by a vertical single line (|) in

the outer margin of the document.

The specific technical differences and their reasons are as follows:

-- Add the scope of application of this document (see Clause 1);

-- Use GB/T 231.1 which adopts the modification of international standard to replace

ISO 6506-1 (see Clause 1, 5.7, Clause 6);

-- Use GB/T 231.2-xxxx which adopts the modification of international standard to

replace ISO 6506-2 (see Clause 1, 5.1 and 5.5);

-- Move the "Note" of 3.1 in ISO 6506-3:2014 to content of the clause (see 4.1);

-- Use JJG 144 to replace ISO 376, to adapt to the technical conditions in China (see

5.4).

1 Scope

This document specifies a method for the calibration of reference blocks to be used in

the indirect verification of Brinell hardness testing machines as described in GB/T

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

version corresponding to that date is applicable to this document; for undated references,

the latest version (including all amendments) is applicable to this document.

GB/T 231.1, Metallic materials - Brinell hardness test - Part 1:Test method (GB/T

231.1-2018, ISO 6506-1:2014, MOD)

GB/T 231.2-2022, Metallic materials - Brinell hardness test - Part 2: Verification and

calibration of testing machines (ISO 6506-2:2017, MOD)

JJG 144, Verification regulation of standard dynamometers

3 Terms and definitions

No terms and definitions need to be defined in this document.

4 Manufacture of reference blocks