GB国家标准 GB/T 39280-2020 钨极惰性气体保护电弧焊用非合金钢及细晶粒钢实心焊丝 GB/T 39280-2020.Rods, wires and deposits for tungsten inert gas welding of non alloy and fine grain ... 07月14日GB/T 39280 阅读全文