中文摘要：

研究了0.21C--1.43Si--1.35Mn钢在两相区及完全奥氏体区采用Q＆P（Quenching and Partitioning）工艺加热后的微观组织与力学性能.结果表明：两相区加热可获得马氏体、残余奥氏体和铁素体组织,钢的抗拉强度为1 013 MPa,延伸率为25%,强塑积为25 655 MPa.%;完全奥氏体区加热可获得马氏体和残余奥氏体组织,钢的抗拉强度为1 257 MPa,延伸率为17%,强塑积为21 454 MPa.%;Q＆P钢中的马氏体主要为板条状,伴有大量位错,并且发现有少量孪晶马氏体,分析认为由配分过程后的淬火过程转变而来;通过Q＆P工艺可得到体积分数高达10.67%的残余奥氏体,分布在板条马氏体间,呈薄膜状.

英文摘要：

The microstructure and mechanical properties of 0.21C-1.43Si-1.35Mn steel heated by a quenching and partitioning （Q＆P） process in the two-phase region and the full austenite region were investigated. The results show that if heating the steel in the two-phase region, the microstructure consists of martensite, retained austenite and ferrite, and the tensile strength, elongation and strength ductility are 1013 MPa, 25% and 25 655 MPa＂ % , respectively. While heating the steel in the full austenite region, the micro- structure consists of martensite and retained austenite, and the tensile strength, elongation and strength ductility are 1 257 MPa, 17% and 21 454 MPa. % , respectively. There is mainly lath martensite along with high-density dislocations in the Q＆P steel. A few twinning martensite transformed after partitioning can be observed as well. Retained austenite with a volume fraction of 10. 67% , distributed within lath martensite, can be acquired in the shape of films after the Q＆P process.