短语词组短語backing g weld 用墊環的銲縫backing groove of weld 銲縫反麪坡口weld backing 銲接襯墊;銲縫襯墊;銲縫墊;銲縫背襯墊nonfusible weld backing 非熔性銲接背墊weld with backing ring 背麪墊環銲接weld with backing strip 背麪墊板條銲接 返回 backing weld