摘要
利用两相区轧制以及增加轧制后弛豫时间的方法,获得了具有不同铁素体-贝氏体/马氏体比例的双相显微组织实验用钢样品。通过对2种实验用钢的EBSD表征发现,对铁素体间的界面和铁素体与贝氏体/马氏体之间的界面而言,如果界面具有较大的整体取向差,则通常也具有较大的解理面取向差和滑移面取向差;但是如果贝氏体和马氏体内部变体间的界面具有较大的整体取向差,则通常也具有较大的解理面取向差,但并不一定具有较大的滑移面取向差,这种现象在马氏体组织中更为显著。双相钢的塑韧性不仅受到两相比例影响,还受两相晶粒细化程度的影响,所以要提高其综合力学性能,需要从有效滑移单元和有效解理单元2个方面对双相组织分别进行细化。
In this study, two dual-phase steels with different ferrite-bainite/martensite ratios were obtained by rolling in two-phase region and setting the relaxation time after rolling. The tested steel with smaller ferrite content obtained higher yield strength and tensile strength, greater total elongation and lower ductile-brittle transition temperature;while the steel with higher ferrite content obtained higher uniform elongation and lower yield strength ratio. The EBSD characterization of the two steels shows that for the ferrite-ferrite boundaries and ferrite-bainite/martensite boundaries, if the interface has a large overall misorientation angle, it usually has a large cleavage plane misorientation angle and large slip plane misorientation angle;but for the variant-variant boundaries within bainite or martensite, if the interface has a large overall misorientation angle, it usually has a large cleavage plane misorientation angle, but not necessarily has a large slip plane misorientation angle, and this phenomenon is more significant in martensite microstructure. The ductility of dual-phase steel is not only affected by the proportion of the two phases, but also influenced by the grain refinement of the two phases. Therefore, in order to improve the comprehensive mechanical properties of the dual phase steel, it is necessary to refine the dual phase microstructure from the view of effective slip unit and the effective cleavage unit.
作者
李秀程
孙明煜
赵靖霄
王学林
尚成嘉
LI Xiucheng;SUN Mingyu;ZHAO Jingxiao;WANG Xuelin;SHANG Chengjia(Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Bejing 100083,China)
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第4期653-660,共8页
Acta Metallurgica Sinica
基金
国家重点研发计划项目No.2017YFB0304900。
关键词
双相钢
显微组织
晶界
取向差
晶粒细化
dual-phase steel
microstructure
grain boundary
misorientation
grain refinement
