Home / Standards / GBT 1979-2001 GBT 1979-2001 Standard diagrams for rating macrostructure and defects of structural steels 结构钢低倍组织缺陷评级图 Standard Type GBT ICS N/A CCS N/A Status N/A Issue Date N/A Implementation N/A Responsible Dept N/A Drafting Unit N/A