Ti-IF钢热镀锌钢板力学性能控制

在设计生产DQ级以下产品的热镀锌机组上进行了Ti-IF钢热镀锌试验,研究了RTH带钢温度和光整对Ti-IF钢热镀锌板组织、织构和力学性能的影响.试验结果表明,以超低碳Ti-IF钢为基础,保证合适的过剩钛,采用合适的工艺制度,可以生产力学性能优良的正常锌花热镀锌钢板,其屈服强度在150 MPa左右,r、n平均值分别达到2.5和0.25.但是,经光整后,屈服强度明显提高,n值明显降低,且成品晶粒尺寸较粗时,光整后的n值较低.根据试验结果,提出了根据热镀锌板表面状态和用户使用条件采用不同的工艺控制技术路线来保证Ti-IF热镀锌板力学性能的策略.

Control of Mechanical Properties of Hot-dip Galvanized Ti-IF Steel Sheet

The hot dip galvanizing experiment of Ti - IF steel was carried out on a CGL line designed for the production of DQ and lower grade products. The effect of RTH strip temperature and skin - passing on the microstructure, recrystallization texture and mechanical properties were investigated. The results show that, based on ULC Ti - IF steel, the hot dip galvanized sheet with excellent formability can be produced when suitable amount of excess Ti is ensured and suitable processing schedule is applied. Its yield strength, average r - value and n -value reach approximately 150 MPa, 2,5 and 0.25, respectively. However, after skin- passing, the yield strength increases obviously, the n - value and elongation decreases markedly. The n - value of final skin- passed products depends on ferrite grain size and becomes very low when the ferrite is coarsened. A strategy to ensure mechanical properties of hot - dip Ti - IF cussed in terms of surface conditions of hot - dip galvanized steel sheet by adjusting process parameter is dissteel sheet and application situation of customer.