GB/T 38720-2020 (English Version) PDF

Scope: This standard specifies the raw materials and requirements for commonly used medium carbon carbon structural steel and medium carbon alloy structural steel, inspection requirements, quenching microstructure grade and evaluation, etc. This standard is applicable to the inspection and evaluation of the microstructure of medium-carbon carbon structural steel and medium-carbon alloy structural steel parts after quenching and tempering. This standard does not apply to the evaluation of the microstructure of medium-carbon carbon structural steel and medium-carbon low-alloy structural steel parts containing decarburization and overburning after quenching and tempering, as well as the microstructure in the isothermal quenching state.

GB/T 38720-2020 Referenced Document

GB/T 10561 Standard grading chart microscopic examination method for determination of non-metallic inclusion content in steel*， 2023-05-23 Update
GB/T 1979 Standard diagrams for macrostructure and defect of structural steels
GB/T 30067 Standard terminology relating to metallography
GB/T 3077 Alloy structure steels
GB/T 34474.1 Determination of banded structure of steel—Part1：Micrographic method using standards diagrams
GB/T 34895 General rules for metallographic examination of heat treatment
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 699 Quality carbon structure steels
GB/T 7232 Metal Heat Treatment Terminology*， 2023-08-06 Update

2020 GB/T 38720-2020 Microstructure examination of medium-carbon steel and medium-carbon alloy structural steel after quenching