冷轧工艺对含Ti高强钢组织和性能的影响  

Effect of cold rolling process on microstructure and mechanical properties of Ti-containing high strength steel

作　　者：李春诚 高国帅 安俊麟 姜乐朋 李科龙 LI Chuncheng;GAO Guoshuai;AN Junlin;JIANG Lepeng;LI Kelong(Technical Center of Bengang Group Corporation,Benxi 117000,China;National and Local Joint Engineering Laboratory of Advanced Automotive Steel Development and Application Technology,Benxi 117000,China;Cold Rolling Mill Plant of Bengang Steel Plates Co.,Ltd.,Benxi 117000,China)

机构地区：[1]本钢集团有限公司技术中心,辽宁本溪117000 [2]先进汽车用钢开发与应用技术国家地方联合工程实验室,辽宁本溪117000 [3]本钢板材股份有限公司冷轧总厂,辽宁本溪117000

出　　处：《轧钢》2025年第1期135-140,共6页Steel Rolling

基　　金：NSFC-辽宁联合基金项目(U1908224);辽宁省“兴辽英才计划”项目(XLYC2007066)。

摘　　要：针对不同屈服强度级别含Ti深冲高强钢生产中合同规格偏差大,造成个别产品订单量偏多或偏少以及炼钢连浇多炉数的难题,有必要采用“一钢多级”或者“一钢多能”的柔性化生产方法,通过控制含Ti深冲高强钢显微组织来保证不同强度级别产品的性能要求,实现低成本、高效化工业生产和管理。采用直拉式四辊可逆冷轧机和退火模拟试验机研究HC220Y含Ti高强钢冷轧和连退生产工艺,结合工业生产实际,研究了不同冷轧压下率、退火温度和平整伸长率对其显微组织和力学性能的影响。试验结果表明:冷轧压下率从70%提高到85%,试验钢的屈服强度增加39MPa,抗拉强度增加42MPa、断后伸长率升高4.5%,塑性应变比r值升高0.25,加工硬化指数n值在0.20左右,大冷轧压下率下试验钢组织内的再结晶晶粒增多,其退火后组织晶粒尺寸变得均匀且细小。退火温度由780℃提高到820℃,试验钢的屈服强度降低32 MPa,抗拉强度降低17MPa,断后伸长率增加3.5%,r值增加0.25,n值几乎没有变化,这是由于连续退火过程中,随着退火温度的升高,提高了试验钢的再结晶温度,增大了其再结晶的驱动力,加快了再结晶的形核速率,再结晶过程所用时间大大缩短。另一方面,热轧生产时Ti微合金元素由于易与C/N结合,沿铁素体晶界上形成粗大的碳氮化钛。连续退火时较高的退火温度容易使碳氮化钛聚集长大,难以阻碍晶粒长大,最终表现出试验钢的晶粒尺寸增大。平整伸长率由0.5%增加到1.0%,试验钢的屈服强度增加了33MPa,抗拉强度没有明显变化,断后伸长率降低约3%,r值降低0.25,n值降低0.02,对于不同强度级别的试验钢工业生产,可以对平整伸长率进行小幅度调整,以满足成品性能要求。The large deviation of contract specifications in the production of Ti-containing deep drawing high strength steel with different yield strength grades led to the problems of more or less orders for individual products and too many heats of continuous casting in steelmaking.It was necessary to adopt the flexible production method of'one steel multi-level'or'one steel multi-function.The microstructure of Ti-containing deep drawing high strength steel was controlled to meet the performance requirements of products with different strength levels,and low-cost and efficient industrial production and management were realized.Cold rolling and continuous annealing process of HC220YTi-containing high strength steel were studied by cold rolling mill with hydraulic tension and continuous annealing simulator.Combined with industrial production test,the influence of cold rolling reduction rate,annealing temperature and temper rolling elongation on microstructure and mechanical properties of the tested steel was studied.The results indicate that the cold rolling reduction rate was increased from 70%to 85%,the yield strength of the tested steel increased by 39MPa,the tensile strength increased by 42MPa,the elongation after fracture increased by 4.5%,the plastic strain ratio(r value)increased by 0.25,and the strain hardening index(nvalue)is about 0.20.The recrystallized grains of the testd steel increased under the large cold rolling reduction rate,and the grain size became uniform and fine after annealing.When the annealing temperature was increased from 780℃to 820℃,the yield strength of the tested steel was decreased by 32MPa,the tensile strength was decreased by 17MPa,the elongation after fracture was increased by 3.5%,the rvalue was increased by 0.25,and the nvalue was almost unchanged.On the one hand,the increase of annealing temperature during continuous annealing process increased the recrystallization temperature of the testd steel,increased the driving force of recrystallization,accelerated the nucleation rate of re

关 键 词：冷轧工艺 含Ti高强钢 组织 力学性能 退火温度 低成本 高效生产 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG335.12[金属学及工艺—金属材料]