压下率对铁素体区轧制高强IF钢组织及性能的影响  

Effect of reduction on microstructure and properties of warm rolled high strength IF steel

作　　者：郭卫民[1,2] 王作成[1,2] 刘胜[1,2] 宋立彬[1,2] 王协彬[1,2] 王晓[1,2] 

机构地区：[1]山东大学材料液固结构演变与加工教育部重点实验室,山东济南250061 [2]山东大学材料科学与工程学院,山东济南250061

出　　处：《材料热处理学报》2011年第4期87-91,共5页Transactions of Materials and Heat Treatment

基　　金：山东省科技厅计划项目(9925)

摘　　要：通过拉伸试验检测力学性能,用金相显微镜观察高强IF钢热轧态及退火态的纤维组织,并用透射电镜观察试验钢中的析出相粒子。在640℃终轧温度下,铁素体区轧制总压下率由60%升高到81%,高强热轧IF钢板的屈服强度为150～180 MPa,抗拉强度为312～321 MPa,屈强比为0.48～0.56,总伸长率为26.4%～31.2%,n值为0.22～0.23,而r值则由1.41降低到1.01,|Δr|则由0.625降低到0.133。结果表明,轧制总压下率对热轧高强IF钢的屈服强度、抗拉强度、总伸长率以及n值影响较小,但是对r值和平面各向异性值Δr的影响非常大。铁素体区轧制总压下率的增大使得高强IF钢热轧板中动态再结晶的驱动力增大,发生动态再结晶晶粒的数目增多,从而导致形变织构的减弱和后续退火再结晶驱动力的减小。同时,随着铁素体区轧制总压下率的增大,高强IF钢退火再结晶程度降低以及析出的粒子变细。Microstructure and mechanical properties of hot rolled and annealed IF steel with different reduction were investigated by means of OM,TEM and tensile tests.When finish rolling temperature is 640 ℃ and the overall reduction of the steel rolled in ferrite region increases from 60% to 81%,the mechanical properties of high strength IF steel are as follows： yield strength is 150-180 MPa,tensile strength is 312-321 MPa,ratio of yield strength to tensite strength is 0.48-0.56,elongation is 26.4%-31.2%,n value is 0.22-0.23,r value is 1.41-1.01 and ｜ Δr ｜ is 0.625-0.133.The results show that rolling reduction has no significant effects on yield strength,tensile strength,elongation and value,but the obvious effects on ｜ Δr ｜ value and r are observed.With increasing reduction of ferrite rolling,the driving force for dynamic recrystallization increases,and more grains are induced to dynamic recrystallization.As a result,deformation texture is weakened and the driving force for later annealing recrystallization decreases.Simultaneously,as enhancing the ferrite rolling reduction,the annealing recrystallization degree of high strength IF steel decreases and the finer precipitates are precipitated.

关 键 词：高强IF钢 压下率 深冲性能 铁素体区轧制 

分 类 号：TG142.1[一般工业技术—材料科学与工程]