Standard No.:	GB/T 5617-2025
English Name:	Determination of surface hardening depth for steel
Chinese Name:	钢件表面淬火硬化层深度的测定
Chinese Classification:	J36    Heat treatment
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR; SAC
Issued on:	2025-8-29
Implemented on:	2026-3-1
Status:	to be valid
Superseding:	GB/T 5617-2005 Determination of effective depth of handening after induction or flame handening of steel
Target Language:	English
File Format:	PDF
Word Count:	8500 words
Translation Price(USD):	255.0
Delivery:	via email in 1~3 business day

GB/T 5617-2025 Determination of surface hardening depth for steel English, Anglais, Englisch, Inglés, えいご This is a draft translation for reference among interesting stakeholders. The finalized translation (passing thorugh draft translation, self-check, revision and varification) will be delivered upon being ordered. ICS 25.200 CCS J36 National Standard of the People's Republic of China GB/T 5617-2025 Replacing GB/T 5617-2005 Determination of Surface Hardening Depth for Steel Issued: 2025-08-29 Implemented: 2026-03-01 Issued by: State Administration for Market Regulation Standardization Administration of China Contents Foreword 1 Scope 2 Normative References 3 Terms and Definitions 4 Symbols and Abbreviations 5 Principle 6 Test Equipment 7 Test Specimens 8 Determination Methods 9 Result Evaluation 10 Test Report Appendix A (Normative) Interpolation Method for Determining Surface Hardening Depth References Determination of Surface Hardening Depth for Steel 1 Scope This document specifies the principles, test equipment, test specimens, determination methods, result evaluation and test reports for measuring surface hardening depth and total hardening depth of steel workpieces. This document is applicable to surface hardened parts produced by induction hardening, flame hardening, laser hardening, electron beam hardening and other surface hardening processes. 2 Normative References The following documents contain provisions which, through reference in this text, constitute essential provisions of this document. For dated references, only the editions cited apply; for undated references, the latest edition (including any amendments) applies. GB/T 4340.1 Metallic materials - Vickers hardness test - Part 1: Test method GB/T 4340.2 Metallic materials - Vickers hardness test - Part 2: Verification and calibration of testing machines GB/T 7232 Heat treatment of metals - Terminology GB/T 18449.1 Metallic materials - Knoop hardness test - Part 1: Test method GB/T 18449.2 Metallic materials - Knoop hardness test - Part 2: Verification and calibration of testing machines 3 Terms and Definitions Terms and definitions defined in GB/T 7232 and the following apply to this document. 3.1 Surface hardening depth (SHD) The vertical distance from the workpiece surface to the specified boundary hardness. Note: Boundary hardness = A × minimum specified surface hardness (HV), where A is typically 0.8. 3.2 Total thickness of surface hardening depth (THD) The distance from the workpiece surface to the boundary with the same hardness as the substrate. Note: Total surface hardening depth can be determined by hardness method or metallographic method, with metallographic method being more commonly used. 4 Symbols and Abbreviations The symbols and abbreviations shown in Table 1 apply to this document. Table 1 Symbols and Abbreviations