初始组织对低碳钢IQ&P工艺残留奥氏体及力学性能的影响  

Effect of Precursor Microstructure on Retained Austenite and Mechanical Property of Low Carbon Steels with IQ&P Treatments

作　　者：陈连生[1] 胡宝佳 宋进英[1] 张健杨 郑小平[1] 魏英立[1] 田亚强[1] 

机构地区：[1]华北理工大学教育部现代冶金技术重点实验室,河北唐山063210

出　　处：《材料工程》2017年第2期96-101,共6页Journal of Materials Engineering

基　　金：国家自然科学基金项目(51574107);河北省自然科学基金项目(E2016209048);河北省高等学校科学技术研究项目(QN2016185);唐山市科技创新团队培养计划项目(15130202C);唐山市科学技术研究项目(14130228B)

摘　　要：采用双相区再加热-淬火-碳配分(IQ&P)工艺,研究初始组织为铁素体+珠光体的IQ&P-Ⅰ多相钢和初始组织为马氏体的IQ&P-Ⅱ多相钢的组织形貌、残留奥氏体及力学性能。结果表明:初始组织为铁素体+珠光体的IQ&P-Ⅰ多相钢室温组织中,铁素体和马氏体基本呈块状分布,块状残留奥氏体存在于铁素体与马氏体界面处,薄膜状只存在于马氏体内的板条之间,且残留奥氏体含量较少,TRIP效应不明显,其抗拉强度为957 MPa,伸长率只有20%,强塑积为19905.6MPa·%。初始组织为马氏体的IQ&P-Ⅱ多相钢中铁素体和马氏体大多呈灰黑色的板条状或针状,且细小的针状马氏体均匀地分布在铁素体基体上,残留奥氏体只以薄膜状平行分布在铁素体基体上,体积分数达到了13.2%,且具有较高的稳定性,TRIP效应较明显,强塑积达到21560MPa·%,可以获得强度和塑性的良好结合。The microstructure, retained austenite and mechanical property of low-carbon steels wi th different precursor microstructures were studied by means of intercritical reheating-quenching and par-titioning （IQ＆P） processes. The results show that the structure of IQ＆P- I multiphase steel with precursor ferrite ＋ pearlite （F＋P） is blocky ferrite, martensite （M）. The blocky retained austenite （RA） of IQ＆P- I multiphase steel exists in the boundary of ferrite and martensite and film-like re-tained austenite distributes around the lath martensite as the shape of thin slice. The transformation induced plastic effect of IQ＆P- I multiphase steel with less content of retained austenite is unappar-ent. The tensile strength of IQ＆P-I multiphase steel reaches 957MPa, but the tensile elongation is only 20% , and the product ion of strength and elongat ion is 19905. 6MPa ？ %. T he s tru c tu re of iq ＆ p - ii multiphase steel with precursor martensite is needle or lath grey-black ferrite and martens-ite. The fine needle like martensite is distributed evenly on the ferrite matrix. The film-like retained austenite is only distributed on the ferrite matrix. The content of retained austenite of IQ＆P-H mul-tiphase steel reaches 13. 2% wi th more obvious TRIP effect and higher stablity . The poduction of strength and elongation of IQ＆P-H multiphase steel is 21560MPa ？ % with good combination of strength and plasticity.

关 键 词：IQ&P工艺 多相钢 残留奥氏体 强塑积 瞬时加工硬化指数 

分 类 号：TG142.4[一般工业技术—材料科学与工程]