高性能汽车钢组织性能特点及未来研发方向

Research and application of high performance automobile steel

介绍了先进汽车用钢的组织和性能特点,认为具有较低强塑积的第一代汽车钢主要是通过铁素体、马氏体等多种基体组织的选取和配合对强度和塑性进行调控,第二代汽车钢通常具有单相奥氏体组织,表现出超高的强塑积,在汽车轻量化和安全性方面都有明显促进作用,但是其高合金质量分数提高了生产成本和难度,不利于规模化生产和应用。而第三代汽车钢则是通过在马氏体或超细晶铁素体基体上引入大量的亚稳奥氏体来提高汽车钢的强度和塑性,从而大幅度提高钢的强塑积。第三代汽车钢综合性能比第一代汽车钢提高1倍以上,其强塑积达到了25~50 GPa·%,接近或达到了第二代汽车钢的强塑积。新型合金化设计、高强度基体组织调控和大量亚稳奥氏体控制是第三代汽车钢的重要研究内容。基于轻量化与高安全性要求,低密度化与高强化将是未来第三代汽车钢的一个主要发展方向。

The features of microstructure and properties of the advanced automobile steels were discussed in this paper.The first generation automobile steel usually has the relatively low product of strength and plastic. It was believed that the strength and plasticity of the first generation automobile steel were mostly controlled by the selection and cooperation of ferrite,martensite and other phases. The ultra high product of strength and plastic was obtained in the second generation austenitic automobile steels with single-phase austenite,which contributed a lot to the lightweight and safety. While the high alloy contents in the second generation automobile steels increased the costs and difficulty of the production,which limited the application and industrialization. Introducing more metastable austenite phase into the martensitic or ultrafine grained ferrite matrix is the main ideas to increase the product of strength and plasticity of the third generation automobile steel. At present,the comprehensive mechanical property of the developed 3rdgeneration automotive steel has increased by more than one time compared with that of the 1stgeneration steel,the product of strength and plasticity approaches closely to that of the 2rdgeneration steel,reaching 25-50 GPa·%. The main research of 3rdgeneration automobile steel in the near future will be focused on the new alloying design,high strength matrix control and high volume metastable austenite development. The trend of future development of 3rdgeneration automobile steels will be both low-density and high strength based on the idea of lighweight and high safety.