This standard specifies the operational requirements for detecting and grading local overheating on the grinding surface of gears by chemical etching methods. It is suitable for grinding surfaces of gears and Miscellaneous quenched steel parts, as well as abnormal surfaces caused by machining after heat treatment. Compared with traditional surface Hardness detection methods, this standard method is more sensitive to Hardness changes and does not recommend previous partial detection methods. This standard does not apply to nitrided parts and stainless steel parts. This method is performed after surface grinding and before final finishing to evaluate surface tempering and ensure part mass and Reliability.