1 Scope
This part of GB/T 230 specifies the method for Rockwell regular and Rockwell superficial hardness tests for metallic materials with scales of A, B, C, D, E, F, G, H, K, 15N, 30N, 45N, 15T, 30T, and 45T.
It is applicable to stationary and portable hardness testing machines. For specific materials or products, other specific standards apply (for instance, GB/T 3849.1[1], GB/T 9097[2]).
Note: Attention is drawn to the fact that the use of tungsten carbide composite for ball indenters is considered to be the standard type of Rockwell indenter ball. Steel indenter balls are allowed to continue to be used only when complying with Annex A.
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 230.2-2012 Metallic materials - Rockwell hardness test - Part 2: Verification and calibration of testing machines (Scales A, B, C, D, E, F, G, H, K, N, T) (GB/T 230.2-2012, ISO 6508-2: 2005, MOD)
GB/T 230.3 Metallic materials - Rockwell hardness test - Part 3: Calibration of reference blocks (Scales A, B, C, D, E, F, G, H, K, N, T) (GB/T 230.3-2012, ISO 6508-3: 2005, MOD)
JJG 112 Metallic Rockwell hardness testers (scales A, B, C, D, E, F, G, H, K, N, T)
JJF 1059.1 Evaluation and expression of uncertainty in measurement
3 Principle
An indenter of specified size, shape, and material is forced into the surface of a test specimen under two force levels using the specific conditions defined in Clause 7. The specified preliminary force is applied and the initial indentation depth is measured, followed by the application and removal of a specified additional force, returning to the preliminary force. The final indentation depth is then measured and the Rockwell hardness value is derived from the difference, h, in the final and initial indentation depths and the two constants N and S (see Figure 1, Table 1, and Table 2) as shown in Formula
Foreword i
1 Scope
2 Normative references
3 Principle
4 Symbols, abbreviated terms and designations
5 Testing machine
6 Test piece
8 Uncertainty of the results
9 Test report
10 Conversions to other hardness scales or tensile strength values
Annex A (Normative) Special HR30TSm and HR15TSm test for thin products
Annex B (Normative) Minimum thickness of the test piece in relation to the Rockwell hardness
Annex C (Normative) Daily verification procedure
Annex D (Normative) Inspection of diamond indenters
Annex E (Normative) Corrections to be added to Rockwell hardness values obtained on convex cylindrical surfaces
Annex F (Normative) Corrections to be added to Rockwell hardness C scale values obtained on convex spherical test surfaces
Annex G (Informative) Uncertainty of the measured hardness values
Bibliography
1 Scope
This part of GB/T 230 specifies the method for Rockwell regular and Rockwell superficial hardness tests for metallic materials with scales of A, B, C, D, E, F, G, H, K, 15N, 30N, 45N, 15T, 30T, and 45T.
It is applicable to stationary and portable hardness testing machines. For specific materials or products, other specific standards apply (for instance, GB/T 3849.1[1], GB/T 9097[2]).
Note: Attention is drawn to the fact that the use of tungsten carbide composite for ball indenters is considered to be the standard type of Rockwell indenter ball. Steel indenter balls are allowed to continue to be used only when complying with Annex A.
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 230.2-2012 Metallic materials - Rockwell hardness test - Part 2: Verification and calibration of testing machines (Scales A, B, C, D, E, F, G, H, K, N, T) (GB/T 230.2-2012, ISO 6508-2: 2005, MOD)
GB/T 230.3 Metallic materials - Rockwell hardness test - Part 3: Calibration of reference blocks (Scales A, B, C, D, E, F, G, H, K, N, T) (GB/T 230.3-2012, ISO 6508-3: 2005, MOD)
JJG 112 Metallic Rockwell hardness testers (scales A, B, C, D, E, F, G, H, K, N, T)
JJF 1059.1 Evaluation and expression of uncertainty in measurement
3 Principle
An indenter of specified size, shape, and material is forced into the surface of a test specimen under two force levels using the specific conditions defined in Clause 7. The specified preliminary force is applied and the initial indentation depth is measured, followed by the application and removal of a specified additional force, returning to the preliminary force. The final indentation depth is then measured and the Rockwell hardness value is derived from the difference, h, in the final and initial indentation depths and the two constants N and S (see Figure 1, Table 1, and Table 2) as shown in Formula
Contents of GB/T 230.1-2018
Foreword i
1 Scope
2 Normative references
3 Principle
4 Symbols, abbreviated terms and designations
5 Testing machine
6 Test piece
8 Uncertainty of the results
9 Test report
10 Conversions to other hardness scales or tensile strength values
Annex A (Normative) Special HR30TSm and HR15TSm test for thin products
Annex B (Normative) Minimum thickness of the test piece in relation to the Rockwell hardness
Annex C (Normative) Daily verification procedure
Annex D (Normative) Inspection of diamond indenters
Annex E (Normative) Corrections to be added to Rockwell hardness values obtained on convex cylindrical surfaces
Annex F (Normative) Corrections to be added to Rockwell hardness C scale values obtained on convex spherical test surfaces
Annex G (Informative) Uncertainty of the measured hardness values
Bibliography
