短语词组短语AC TIG welding arc 交流TIG电弧TIG Arc welding machine 钨极氩弧焊机tig arc welding tig 焊接pulsed tig arc welding 脉冲钨极氩弧焊arc tig welding tig 焊TIG -Tungsten Inert Gas Arc Welding 钨极惰性气体保护焊 返回 tig welding arc