双相钢属于相变强化高强度钢，是指通过采用特定的化学成分和生产工艺在钢的铁素体基体上弥 散分布一定量的马氏体，形成以铁素体加马氏体为主的组织，在提高强度的同时改善钢的成形性能。具 有屈服比低、无屈服延伸、应变强化指数高和良好的抗碰撞性能，可以实现在减轻汽车重量的同时提高 安全性能，是今年来发展起来的先进高强钢吗，在汽车工业发达国家已经批量使用。主要用于汽车车轮、 保险杠、悬挂系统和加强件 , 也可用于汽车内外板。 High-strength dual-phase steel, a phase change strengthening steel, is in a structure mainly composed of ferrite and martensite, which is dispersed in certain quantity to ferritic matrix by adoption of special chemical compositions and production process. Its strength can be improved, at the same time the formability also can be enhanced. It is featured with low yield strength, no yield elongation, high strain strengthening index and excellent collision-resistance. It also can increase safety of automobiles while lowering their weight. It is a kind of recently developed advanced high-strength steel and it has been applied in batches to automotive industry in developed countries. It is mainly used for manufacturing wheels, bumpers, suspension systems and reinforcements as well as outside plates of automobiles.