短语词组短語powder submerged -arc 粉末埋弧銲submerged -arc smelting 埋弧冶鍊Submerged -arc welding power 埋弧銲接電源double submerged -arc welding 雙絲埋弧銲multiplewire submerged -arc welding 多絲埋弧銲 返回 submerged arc