短語詞組短語external backing welding 外焊根焊flux copper backing welding 銅板墊單面潛弧焊brick backing welding 磚形襯墊單面焊flux asbesto backing welding 石棉墊單面潛弧焊backing welding electrode 底層焊條flux coppor backing welding 銅板墊單面潛弧焊接Ceramic backing welding 陶質(zhì)襯墊焊flux asbestos backing welding 石綿墊單面潛弧焊welding backing 焊接襯墊 返回 backing welding