短语词组短语butt seam weld 对线焊;对接滚焊焊缝butt joint weld 对接焊butt groove weld 对接坡口焊butt -weld 对头焊接;平式焊接;碰焊;以对头焊接接合plain butt -weld 对焊flash butt -weld 闪光对接焊缝 返回 butt weld