连续退火工艺参数对1180 MPa级含Nb增强成形性双相钢组织性能的影响  

Effect of continuous annealing process parameters on microstructure and properties of 1180 MPa grade Nb-microalloyed dual phase steel with high formability

作　　者：杨玉环 褚晓红 路洪洲 韩赟 阳锋 赵征志 YANG Yuhuan;CHU Xiaohong;LU Hongzhou;HAN Yun;YANG Feng;ZHAO Zhengzhi(Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing 100083,China;Beijing Engineering Technology Research Center of Special Steel for Traffic and Energy,Beijing 100083,China;CITIC Metal Co.,Ltd.,Beijing 100004,China;Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China)

机构地区：[1]北京科技大学钢铁共性技术协同创新中心,北京100083 [2]北京市交通与能源用特殊钢工程技术研究中心,北京100083 [3]中信金属股份有限公司,北京100004 [4]首钢集团有限公司技术研究院,北京100043

出　　处：《中国冶金》2024年第1期72-80,共9页China Metallurgy

基　　金：中信集团重大科技创新项目(2022ZXKYA06100);新能源汽车材料生产应用示范平台项目(TC180A6MR-1);中央高校基本科研业务费资助项目(FRF-BD-23-01)。

摘　　要：为实现节能减排的目的,汽车车身正朝着轻量化、高质量的方向发展,DH钢因其优良的强塑性能而具有广泛的应用前景。基于实验室模拟连续退火与组织性能表征分析,研究开发了一种综合性能良好的1180 MPa级含Nb增强成形性双相钢。连续退火试验结果表明,随着退火温度的升高,钢中马氏体、贝氏体含量升高,试验钢的抗拉强度在870℃升高至1200 MPa;退火温度进一步上升时,马氏体回火程度增大且贝氏体含量增加导致钢的强度略微降低。随着过时效温度的升高,试验钢抗拉强度逐渐降低,伸长率在370℃升高至16.2%。基于连续退火试验结果与工业生产线特点,实现了DH1180钢的工业试制。所得样品显微组织由铁素体、马氏体、贝氏体、残余奥氏体(φ(γ)=6.62%)组成,组织中弥散分布着纳米级的(Nb,Ti)C析出相,呈现出优良的强塑性匹配,试验钢的抗拉强度为1257 MPa,伸长率达到15.6%。DH1180钢的开发与应用为汽车用高强钢提供了更多的可能性。In order to achieve the goal of energy conservation and emission reduction,automobile bodies are developing towards lightweight and high-quality direction.DH steel has a wide application prospect due to its excellent strength and plasticity performance.The high formability 1180 MPa grade Nb-microalloyed dual phase steel,exhibiting excellent properties,had been developed through laboratory simulated continuous annealing and characterization analysis of microstructure and properties.The results of continuous annealing tests reveal that the increase of annealing temperature lead to corresponding rise in the content of martensite and bainite,consequently resulting in enhancement of tensile strength up to 1200 MPa at 870℃.As the annealing temperature further increases,the volume fraction of tempered martensite and the bainite increases,resulting in slight decrease in strength.As the over-aging temperature increases,the tensile strength gradually decreases and the elongation increases to 16.2%at 370℃.Based on the continuous annealing test results and the feature of industrial production line,DH1180 continuous annealing plates was industrially produced.Its microstructure is composed of ferrite,martensite,bainite,and residual austenite(φ(γ)=6.62%),dispersed with nano-scaled(Nb,Ti)C precipitates,showing superior match of strength and plasticity with tensile strength of 1257 MPa and elongation of 15.6%.The development and application of DH1180 steel provides more possibilities for high-strength steel for automobile.

关 键 词：连续退火 残余奥氏体 析出相 组织性能 增强成形性双相钢 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG156.2[金属学及工艺—金属材料]