Home / Standards / GB/T 39255-2020 GB/T 39255-2020 Active Gases and gas mixtures for welding and cutting processes 焊接与切割用保护气体 Standard Type GBT ICS 25.160.20 CCS J33 Status 现行 Issue Date 2020-11-19 Implementation 2021-06-01 Responsible Dept 国家标准委 Drafting Unit N/A