GB/T 17879-2023 Active

This document specifies the operation and requirements for detecting and grading local overheating on grinding surfaces using chemical etching methods.
The detection method described in this document is mainly used for gear grinding surfaces, and can also be used for abnormal surfaces formed after heat treatment due to machining (such as hard turning, milling, deburring, chamfering, etc.). The detection of surface metallographic changes caused by carburizing and decarburizing can be referenced for use.
Compared with most surface hardness detection methods, the method described in this document is more sensitive to hardness changes, and some previous detection methods are no longer recommended in this document.
This document is applicable to quenched steel parts such as gears, shafts, splines, and bearings, but not to nitrided parts and stainless steel parts.
Note: This method is sometimes referred to as "nitric acid etching", but it should not be confused with other methods of "nitric acid etching".
The surface temper etching process is used after surface grinding and before final finishing (such as super-finishing, shot peening, and honing).