工厂生产实际中,常常会接触到进口钢材,为在船舶、机械结构的建造中很好地使用这些新材料,首先必须搞清它由哪一个国家进口,是按什么标准生产的,以查到它的化学成分和物理性能,然后才能进行设计、施工和生产。 Factories often have access to imported steel products. In order to make good use of these new materials in the construction of ships and mechanical structures, it is necessary to first find out from which country they are imported and what is the standard for their production so as to find out Its chemical composition and physical properties before it can be designed, constructed and manufactured.