短语词组短语welding multi billet rolling 焊接小方坯轧制shaped billet rolling machine 异性坯辊道billet rolling train 小胚辊轧系列whole billet rolling 整坯轧制rolling billet 轧制用钢坯;轧制用坯hot -rolling billet 热轧坯料 返回 billet rolling