常見(jiàn)例句雙語(yǔ)例句Introduction on the development of downward welding skills , mainly on the application and main characteristics.介紹了下向焊焊接技術(shù)的發(fā)展，主要敘述了該工藝管道建設(shè)中的應(yīng)用和主要特點(diǎn)。In horizontal position welding, the gravity makes molten metal flow downward and sometimes causes weld defects such as undercut and overlap.橫向焊接時(shí)由于熔化金屬重力的作用，會(huì)引起熔池金屬下淌，從而產(chǎn)生咬邊以及焊瘤等焊接缺陷。 返回 downward welding