C-Si-Mn-Cr双相钢组织与性能的柔性控制技术

Flexible control on microstructure and mechanical properties of C-Si-Mn-Cr dual phase steel

以C-Si-Mn-Cr成分体系双相钢为研究对象,采用金相显微镜、扫描电镜、拉伸试验等方法,对终轧温度、卷取温度、退火温度等工艺参数对C-Si-Mn-Cr系双相钢组织和性能的影响进行了研究。结果表明,降低终轧和卷取温度,热轧板组织由铁素体+珠光体转变为铁素体+珠光体+贝氏体,同时热轧板的屈服强度和抗拉强度都有所提高;当冷轧和退火工艺相同时,对采用低温终轧和低温卷取生产的双相钢来说,其抗拉强度由472 MPa增加到524 MPa,而屈服强度则变化不大,此时伸长率和n值略有降低;通过采用低温卷取+中温退火工艺,可以实现一种成分体系生产CR260/450DP和CR290/490DP两种强度级别双相钢的柔性化生产目标。

The influence of finishing temperature,coiling temperature,and annealing temperature on the microstructure evolution and mechanical properties of C-Si-Mn-Cr dual phase steel were studied by using of optical microscope,scanning electronic microscope,and tensile test.The results show that when decreasing finish rolling temperature and coiling temperature,the microstructure changes from ferrite+pearlite to ferrite+pearlite+bainite,meanwhile the yield strength and ultimate tensile strength increases gradually.When cold rolling and annealing processes are the same,the tensile strength of dual phase steel produced with lower finish rolling and coiling temperatures increases from 472 MPa to 524 MPa,but the yield strength changes a little,and the n value and elongation decrease.In this research,a flexible production of dual phase steels specified as CR260/450 DP and CR290/490 DP respectively with the same chemical composition are achieved using lower coiling temperature and moderate annealing temperature.