退火工艺对电池壳用IF钢的组织、织构及力学性能的影响  

Effect of annealing process on microstructure,texture and mechanical properties of IF steel for battery shell

作　　者：张佳奇 宋新莉[1] 贾涓[1] 陈天宇 葛锐 ZHANG Jia-qi;SONG Xin-li;JIA Juan;CHEN Tian-yu;GE Rui(State Key Laboratory of Refractory and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《材料热处理学报》2023年第12期70-77,共8页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51101114)。

摘　　要：新能源汽车电池壳用无间隙原子(IF)钢不仅要求有一定的强度,而且需要优异的深冲性能,因此需要优化退火工艺参数,控制组织织构演变以获得对深冲性能有利的{111}面织构与高强度。对厚度为0.30 mm的电池壳用IF钢冷轧板在720~810℃进行再结晶退火3 min,借助光学显微镜、电子背散射衍射(EBSD)技术和万能拉伸试验机等分析了退火IF钢的组织、织构、屈服强度、抗拉强度、塑性应变比r值与应变硬化指数n值,研究不同温度退火对IF钢组织、织构及力学性能等的影响规律与机理。结果表明:冷轧板晶粒沿轧制方向拉长,冷轧板在720~810℃退火3 min后,均得到等轴状铁素体,平均晶粒尺寸由8.43μm增大至11.64μm。冷轧IF钢退火后得到强的{111}面织构,主要由{111}<110>和{111}<112>两类取向晶粒组成,其含量随着退火温度的升高而增加。在780℃退火时由于部分{110}<001>织构吞噬{111}<110>、{111}<112>织构,导致{111}织构发生突降。随退火温度的升高,IF钢的屈服强度与抗拉强度下降;0°、45°与90°方向的塑性应变比r值增大,各向异性Δr值增大。The interstitial-free(IF)steel used for new energy vehicle battery shells not only requires certain strength,but also excellent deep drawing performance.Therefore,it is necessary to optimize annealing process parameters,control the evolution of microstructure and texture to obtain{111}texture that is beneficial for deep drawing performance and high strength.The cold rolled IF steel sheet for battery shell with thickness of 0.30 mm was annealed at 720-810℃for 3 min.Microstructure,texture,yield strength,tensile strength,plastic strain ratio r and strain hardening index n of the annealed IF steel were analyzed by means of optical microscope,electron backscatter diffraction(EBSD)technique and universal tensile testing machine.The influence of different annealing temperature on the microstructure,texture and strength of the IF steel was investigated.The results show that the grain size of the cold rolled sheet is elongated along the rolling direction,and after annealing at 720-810℃for 3 min,equiaxed ferrite is obtained,with an average grain size of 8.43μm increasing to 11.64μm.After annealing,the cold rolled IF steel obtains strong{111}texture,mainly composed of two types of oriented grains:{111}<110>and{111}<112>,and its content increases with the increase of annealing temperature.After annealing at 780℃,some{110}<001>textures engulf{111}<110>and{111}<112>textures,resulting in a sudden decrease in{111}texture.As the annealing temperature increases,the yield strength and tensile strength of the IF steel decrease,and the plastic strain ratio r values in the 0°,45°and 90°directions and the anisotropyΔr values increase.

关 键 词：无间隙原子钢 织构 塑性应变比 退火温度 

分 类 号：TG142.3[一般工业技术—材料科学与工程]