GB/T 17394.2-2022 English PDF (GBT17394.2-2022)

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GB/T 17394.2-2022: Metallic materials - Leeb hardness test - Part 2: Verification and calibration of hardness testers
GB/T 17394.2-2022
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 19.060; 77.040.10
CCS N 71
Replacing GB/T 17394.2-2012
Metallic Materials - Leeb Hardness Test - Part 2:
Verification and Calibration of Hardness Testers
(ISO 16859-2:2015, Metallic Materials - Leeb Hardness Test - Part 2: Verification
and Calibration of the Testing Devices, MOD)
ISSUED ON: JULY 11, 2022
IMPLEMENTED ON: FEBRUARY 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
Introduction ... 5
1 Scope ... 6
2 Normative References ... 6
3 Terms and Definitions ... 6
4 General Requirements ... 6
5 Direct Inspection ... 7
5.1 General Rules ... 7
5.2 Technical Parameters ... 7
5.3 Inspection of Mass and Geometric Dimensions of Impact Body ... 9
5.4 Inspection of Geometric Dimensions and Hardness of Ball Head ... 9
5.5 Inspection of Geometric Dimensions of Support Ring ... 9
5.6 Inspection of Impact Velocity ... 10
5.7 Indirect Inspection of Hardness Tester ... 10
6 Indirect Inspection ... 10
6.1 General Rules ... 10
6.2 Method ... 11
6.3 Coefficient of Variation (V) ... 11
6.4 Relative Error of Indication ... 12
6.5 Uncertainty of Measurement ... 13
7 Inspection Cycle ... 13
8 Inspection Report and / or Calibration Certificate ... 14
Appendix A (informative) Measurement Uncertainty of Calibration Results of Hardness
Testers ... 15
Appendix B (informative) Direct Inspection of Single-coil Hardness Tester ... 19
Bibliography ... 21
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 2 of GB/T 17394 Metallic Materials - Leeb Hardness Test. GB/T 17394
has issued the following parts:
---Part 1: Test Method;
---Part 2: Verification and Calibration of Hardness Testers;
---Part 3: Calibration of Reference Test Blocks;
---Part 4: Tables of Hardness Values Conversation.
This document serves as a replacement of GB/T 17394.2-2012 Metallic Materials - Leeb
Hardness Test - Part 2: Verification and Calibration of Hardness Testers. In comparison with
GB/T 17394.2-2012, the main technical changes are as follows:
---The DC-type impact device is deleted (see Chapter 1 of Version 2012);
---The inspection items are modified (see Chapter 4; Chapter 3 of Version 2012);
---The inspection of impact velocity and support ring is added (see 5.1.3);
---The relevant requirements for direct inspection are modified (see Chapter 5; Chapter 4
of Version 2012);
---The relevant requirements for indirect inspection are added (see 6.1.2 ~ 6.1.4);
---The hardness range of the reference Leeb hardness test blocks is modified (see Table 2;
Table 4 of Version 2012);
---The inspection cycle is modified (see Chapter 7; Chapter 6 of Version 2012);
---The type of impact device for hardness testers is deleted (see Appendix A of Version
2012);
---The direct inspection of the single-coil hardness tester is added (see Appendix B).
This document modifies and adopts ISO 16859-2:2015 Metallic Materials - Leeb Hardness Test
- Part 2: Verification and Calibration of the Testing Devices.
There are technical differences between this document and ISO 16859-2:2015, and the clauses
involved in these differences have been marked by a single vertical line () in the outer margin
of the document. The specific technical differences and the causes for these differences are as
follows:
Metallic Materials - Leeb Hardness Test - Part 2:
Verification and Calibration of Hardness Testers
1 Scope
This document specifies the methods for the direct inspection and indirect inspection of the
Leeb hardness testers (hereinafter referred to as hardness testers) in accordance with GB/T
17394.1.
The direct inspection is suitable for checking whether the performance parameters of the
hardness testers are within the specified range. The indirect inspection is to use the hardness
value of the reference Leeb hardness test blocks calibrated in accordance with GB/T 17394.3
to check the overall performance of the hardness testers in the direction of gravity. Indirect
inspection can be independently applied to regular routine checks of in-use hardness testers.
This document is applicable to hardness testers equipped with D, S, E, D + 15, DL, C and G-
type impact devices.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in the text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 4340.1 Metallic Materials - Vickers Hardness Test - Part 1: Test Method (GB/T 4340.1-
2009, ISO 6507-1:2005, MOD)
GB/T 17394.1 Metallic Materials - Leeb Hardness Test - Part 1: Test Method
GB/T 17394.3-2022 Metallic Materials - Leeb Hardness Test - Part 3: Calibration of Reference
Test Blocks (ISO 16859-3:2015, MOD)
3 Terms and Definitions
This document does not have terms or definitions that need to be defined.
4 General Requirements
Before inspecting the hardness testers, they shall be checked to ensure that the hardness testers
are correctly installed and operated in accordance with the manufacturer’s instructions.
5.3 Inspection of Mass and Geometric Dimensions of Impact Body
5.3.1 The mass of the impact body shall satisfy the requirements specified in Table 1.
5.3.2 The impact body shall consist of a ball head and a bracket. If the impact signal is read
through the electromagnetic induction coil, then, the impact body shall contain a permanent
magnet.
5.3.3 For D, D + 15, S, E and C-type impact devices, the tip of the ball head shall protrude from
the grip by at least 0.3 mm. For G-type impact device, the tip of the ball head shall protrude
from the grip by at least 0.6 mm. For DL-type impact device, the diameter of the gripped round
steel bar is (2.5  0.1) mm, the length is (55.15  0.1) mm and the tip of the ball head shall
protrude from the grip by at least 2 mm.
5.4 Inspection of Geometric Dimensions and Hardness of Ball Head
5.4.1 In order to inspect the geometric dimensions and hardness of the ball head, randomly take
a sample from a batch of balls to test its diameter and hardness. This batch of balls shall be
provided with a certificate of conformity or evidence of the required hardness. Balls subjected
to the hardness test shall be discarded.
5.4.2 The diameter of the ball head shall be determined by measuring different positions on the
ball to obtain the arithmetic mean of not less than three diameter values. The difference between
a single measured value at any position and its nominal value shall satisfy the requirements in
Table 1.
5.4.3 The ball head shall be made of tungsten-cobalt cemented carbide, ceramics or synthetic
diamond (as shown in Table 1). The hardness test shall be carried out in accordance with the
stipulations of GB/T 4340.1, and the hardness value shall comply with the stipulations of Table
1. The steel ball can be tested directly on the spherical surface, or sliced inside the steel ball.
Synthetic diamond balls do not need to be inspected for hardness.
5.4.4 When conductin...