Metallic Materials — Leeb Hardness Test — Part 3: Calibration of Reference Test Blocks
1 Scope
This document specifies a method for the calibration of reference test blocks that are used for the indirect verification of Leeb hardness testers according to GB/T 17394.2 and for the periodic checking according to GB/T 17394.1. This document also specifies the procedures necessary to ensure metrological traceability of the Leeb hardness calibration machine.
This document is applicable to the calibration of Leeb hardness reference test blocks (hereinafter referred to as "reference test blocks").
2 Normative References
The following referenced documents are indispensable for the application 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.
GB/T 231.3-2012 Metallic materials — Brinell hardness test — Part 3: Calibration of reference test blocks (ISO 6506-3:2005, MOD)
GB/T 4340.3-2012 Metallic materials — Vickers hardness test — Part 3: Calibration of reference test blocks (ISO 6507-3:2005, MOD)
GB/Z 17394.1 Metallic materials — Leeb hardness test — Part 1: Test method
GB/T 17394.2-2022 Metallic materials — Leeb hardness test — Part 2: Verification and calibration of hardness tester (ISO 16859-2:2015, MOD)
GB/T 27025 General requirements for the competence of testing and calibration laboratories (GB/T 27025-2008, ISO/IEC 17025:2005, IDT)
3 Terms and Definitions
No terms and definitions are listed in this document.
4 Manufacture of Reference Test Blocks
4.1 The block shall be specially manufactured for use as a reference block. Attention is drawn to the need to use a manufacturing process which will give the necessary homogeneity, stability of texture and uniformity of surface hardness.
4.2 The uniformity of the metallic reference test block shall meet the requirements specified in 8.2 and Table 3.
4.3 The impact nature of a Leeb test requires a reference test block with a minimum mass and thickness, as specified in Table 1. Examples of common dimensions of reference test blocks are specified in Annex A.
Table 1 Mass and geometry of reference test block
Foreword II
Introduction IV
1 Scope
2 Normative References
3 Terms and Definitions
4 Manufacture of Reference Test Blocks
5 Calibration Machine
5.1 General
5.2 Traceability
5.3 Requirements on calibration machines
5.4 Calibration of calibration machines
6 Calibration Procedure
7 Number of Test Indentations
8 Uniformity of Hardness
9 Marking
10 Validity
Annex A (Informative) Examples of Reference Test Block
Annex B (Normative) Requirements for Leeb Hardness Calibration Machines
Annex C (Informative) Measurement Uncertainty of Hardness Values of Reference Test Block
Annex D (Normative) Procedures for Use of Reference Test Block of Calibration Machines according to the Principle of Non-Leeb Hardness Test
Annex E (Informative) Conversion Table of Vickers Hardness Value/Brinell Hardness Value and Leeb Hardness Value of Reference Test Block
Bibliography
