热轧双相钢的发展现状及高强热轧双相钢的开发

摘要

介绍了热轧双相钢的发展现状及存在问题，指出低成本热轧双相钢、高延伸凸缘型铁素体+贝氏体热轧双相钢（F-B热轧双相钢）及高强度热轧双相钢的开发及应用，将促进我国热轧双相钢的发展，推动汽车工业的“以热代冷”进程。同时，探讨了纳米析出强化型热轧双相钢的强化机理及工艺控制原理，并在实验室进行了中试，开发出铁素体基体析出强化型的热轧双相钢，其抗拉强度达770~830 MPa，屈强比＜0.75，组织为铁素体+马氏体，且铁素体基体中存在大量细小的纳米级尺寸的TiC过饱和析出和相间析出。%This paper introduces the development status and existing problems of hot rolled dual-phase steel,and points out that the development and application of low-cost hot rolled du-al-phase steel,F-B hot rolled dual-phase steel and high strength hot rolled dual-phase steel would promote the development of hot rolled dual phase steel and the process of replacement of cold rolled products by hot rolled ones in automobile industry. Strengthening mechanism and process control principle of hot rolled dual-phase steel strengthened by ferrite matrix with fine precipitates are also discussed. And the hot rolling experiments were carried out at laboratory. The hot rolled dual-phase steel strengthened by ferrite matrix with fine precipitates has been de-veloped. This steel contains martensite islands and ferrite matrix distributing a large number of supersaturated precipitates and interphase precipitation of finer nano-sized TiC,whose tensile strength reaches up to 770~830 MPa with the yield ratio of less than 0.75.