390MPa级Ti+Nb超低碳高强度BH钢组织性能研究

对Ti+Nb+B复合处理超低碳高强度BH钢的热轧、冷轧和连续退火进行实验。结果表明:试制的超低碳高强度BH钢退火板的屈强比为0.536,烘烤硬化值为44MPa,具有较为优良的成形性能和烘烤硬化性能,抗拉强度为394MPa,达到了390MPa级超低碳高强度BH钢板的强度要求。物理化学相分析表明:添加在超低碳高强度BH钢中的B除了析出了2mg/kg的BN,大部分的B在钢中以间隙固溶的形式存在,对超低碳高强度BH钢基体起到了固溶强化的作用。

Microstructure and Mechanical Property of 390MPa Grade Ti+Nb Bearing High Strength Ultra-low Carbon Bake Hardening Sheet Steel

Hot rolling, cold rolling and continuous annealing of Ti+Nb+B bearing high strength ultra-low carbon bake hardening steel were studied.The results show that the developed high strength ultra-low carbon bake hardening steel possesses superior formability and excellent bake hardenability.The ratio of the yield strength to tensile strength is 0.536.The bake hardening value is 44MPa.The tensile strength of the developed steel is 394MPa, which meets the requirements of the 390MPa grade high strength ultra-low carbon bake hardening steel.It has been shown from the results of physicochemical phase analysis that most of the alloying element B in the high strength ultra-low carbon bake hardening steel exists in the form of interstitial solid solution and plays a role in the solid solution strengthening besides 2mg/kg BN precipitation.