高强双相钢的工艺设计与组织性能分析  

Process design and analysis of microstructure and mechanical properties for high strength dual phase steels

作　　者：王业勤 刘万春 郭亚南 王国强 侯晓英 毕永杰 丁明凯 陈钢 WANG Yeqin;LIU Wanchun;GUO Yanan;WANG Guoqiang;HOU Xiaoying;BI Yongjie;DING Mingkai;CHEN Gang(Iron and Steel Research Institute,Shandong Iron and Steel Group Rizhao Co.,Ltd.,Rizhao 276805,Shandong,China)

机构地区：[1]山东钢铁集团日照有限公司钢铁研究院,山东日照276805

出　　处：《中国冶金》2025年第2期45-54,共10页China Metallurgy

基　　金：山东省自然科学基金青年基金资助项目(ZR2021QE262)。

摘　　要：为实现双相钢材料“素化”,采用低成本成分设计,通过2种退火工艺处理,得到不同的相组成,从而获得F/M和F/B 2种不同力学性能特征的高强双相钢材料,并分析了微观组织形貌和力学性能特征。结果表明,F/M双相钢由62%铁素体和38%马氏体组成;铁素体存在再结晶和取向附生铁素体2种形态,晶粒平均直径约为3.9μm,块状马氏体晶粒直径为0.5~2.5μm;其断后伸长率达到17.6%,而屈服强度及屈强比较低,分别为588 MPa和0.547。F/B双相钢由40%铁素体、49%粒状贝氏体及11%残留奥氏体组成;铁素体只存在再结晶铁素体1种形态,晶粒平均直径约为3.4μm;其扩孔率和强塑积均较高,分别为33%和20.38 GPa·%。不同于F/M钢的微孔长大聚集型断裂,F/B双相钢在三相协调变形作用下强塑匹配性有效提高,断后伸长率为16.2%,同时屈服强度和抗拉强度分别达到812、1258 MPa,相较于F/M双相钢,其提高幅度分别达到38.1%和17.0%。F/M双相钢中两相交界处存在较大的界面能级差,扩孔过程中微裂纹会直接在F/M两相交界处迅速扩展直至断裂;而对于F/B双相钢,贝氏体内部岛状组织尺寸不一,其强度可有效削弱或钝化微裂纹尖端所承受的局部应力作用,从而提高其扩孔性能,扩孔率达到33%。研究结果对高强双相钢材料实现高性能以及多用途的设计和制造具有一定的参考意义。In order to realize the making materials plain of dual-phase steel,a low-cost composition design was adopted.Different phase compositions were obtained by two continuous annealing processes,so as to obtain two high strength dual phase steel materials with different mechanical properties of F/M and F/B,and the microstructure and mechanical properties were analyzed.The results show that the F/M dual phase steel is composed of 62%ferrite and 38%martensite.There are two forms of ferrite,recrystallization and oriented epitaxial ferrite.The average grain diameter is about 3.9μm,and the grain diameter of block martensite is 0.5-2.5μm.The elongation after fracture reaches 17.6%,while the yield strength and yield strength ratio are low,which are 588 MPa and 0.547.The F/B dual phase steel is composed of 40%ferrite,49%granular bainite and 11%retained austenite.There is only one form of recrystallized ferrite in the ferrite,and the average grain diameter is about 3.4μm.The pore expansion rate and product of strength and elongation are high,which are 33%and 20.38 GPa·%,respectively.Different from the microvoid growth and aggregation fracture of F/M steel,F/B dual phase steel can effectively improve its strength and plasticity matching under the action of three-phase coordinated deformation.The elongation after fracture is 16.2%,and the yield strength and tensile strength are 812 and 1258 MPa,respectively,and compared with F/M dual phase steel,the increase is 38.1%and 17.0%,respectively.There is a large interfacial energy level difference at the interface of the two phases in the F/M dual phase steel,and the microcracks will directly expand at the interface of the F/M two phases until fracture during the reaming process.For F/B dual phase steel,the size of island structure in granular bainite is different,and its strength can effectively weaken or passivate the local stress of micro-crack tip,so as to improve its hole expansion performance,and the hole expansion rate reaches 33%.The research results have certain reference

关 键 词：双相高强钢 工艺设计 微观组织 形貌特征 力学性能 扩孔性能 

分 类 号：TG142.1[一般工业技术—材料科学与工程]