Nb及二次淬火对Q＆P钢组织性能的影响

主要对0.19C-1.52Si-1.53Mn-0.14Al-0.048Nb和0.19C-1.52Si-1.48Mn-0.15Al两种成分的钢进行了Q＆ P(quenching and partitioning)工艺处理，并研究二次淬火对Q＆ P钢组织性能的影响.结果表明:Nb的加入能够起到细晶强化和沉淀强化的效果，提高Q＆ P钢的综合性能.强塑积最高可达到25190MPa·%.二次淬火能够提高实验钢最终的马氏体含量，并大大提高钢的抗拉强度和屈服强度，降低了实验钢的应变硬化指数和总延伸率.若不采用二次淬火则会使实验钢的塑性大大提高，综合力学性能较高.

Effects of Nb and Final Quenching on Microstructure and Mechanical Property of Q&P Steels

Two kinds of steels 0.19C-1.52Si-1.53Mn-0.14Al-0.048Nb and 0.19C-1.52Si-1.48Mn-0.15Al were treated by Q&; P (quenching and partitioning) process. The effect of final quenching on the microstructure and mechanical property of Q&; P steels was studied. The results showed that the addition of Nb has the effect of fine grain strengthening and precipitation strengthening. The combination of elongation and tensile strength achieves 25190 MPa·%. And the final quenching process increases the volume of martensite and greatly improves the tensile strength and yield strength of Q&; P steels. Meanwhile, this process decreases the total elongation and work hardening index of the steels. The steels without final quenching process have the better mechanical properties with high total elongation but the relatively low strength.