Home / Standards / GB/T 38720-2020 GB/T 38720-2020 Active Microstructure examination of medium-carbon steel and medium-carbon alloy structural steel after quenching 中碳钢与中碳合金结构钢淬火金相组织检验 Standard Type GBT ICS 25.200 CCS J36 Status 现行 Issue Date 2020-03-31 Implementation 2020-10-01 Responsible Dept 国家标准委 Drafting Unit N/A