短语词组短语double butt strap seam 双衬板对接缝butt welding seam 对接焊缝mitred butt welded seam 斜对接焊缝butt welded seam 对焊缝butt weld seam 对接缝butt welds seam 对接焊缝resistance butt -seam welding [电]电阻对缝焊接butt -seam-welding 对缝焊 返回 butt seam