D0L:10.13374/.issn1001-053x.2013.12.008 第35卷第12期 北京科技大学学报 Vol.35 No.12 2013年12月 Journal of University of Science and Technology Beijing Dec.2013 基于动态相变的热轧Nb-V-Ti微合金化TRIP钢 组织及性能 王明庆1)，李龙飞1)凶，杨王玥，孙祖庆) 1)北京科技大学新金属材料国家重点实验室，北京100083 2)北京科技大学材料科学与工程学院，北京100083 ☒通信作者，E-mail:ilf@skl.ustb.cdu.cm 摘要通过单轴热压缩试验，结合扫描电镜以及X射线衍射技术，研究了动态相变前奥氏体晶粒状态对基于动态相 变的热轧Nb-V-Ti微合金化TRIP钢复相组织状态及力学性能的影响.与动态相变前奥氏体晶粒为等轴状条件下相比， 动态相变前奥氏体晶粒为拉长状条件下，动态相变得到的铁素体转变量较大，最终复相组织中贝氏体含量较少且团径较 小，马氏体含量较少，但对残余奥氏体含量及其含碳量影响不明显.与不含微合金化元素的基于动态相变的热轧TP 钢相比，Nb-V-Ti微合金化TRIP钢的屈服强度和抗拉强度明显提高，而延伸率有所降低. 关键词热轧：TRP钢：相变：微合金化：奥氏体：力学性能 分类号TG142.1 Microstructure and mechanical properties of hot-rolled Nb-V-Ti microalloyed TRIP steel based on dynamic transformation of undercooled austenite WANG Ming-qing),LI Long-fe),YANG Wang-yue2),SUN Zu-qing) 1)State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China 2)School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:lilfaskl.ustb.edu.cn ABSTRACT The influence of the state of prior austenite grains before dynamic transformation on the multi-phase microstructure and mechanical properties of hot-rolled Nb-V-Ti microalloyed TRIP steel based on dynamic transforma- tion of undercooled austenite(DTUA)was investigated by uniaxial hot compression test,scanning electron microscopy, and X-ray diffraction.In comparison with that prior austenite grains are equiaxed before DTUA,when prior austenite grains are elongated before DTUA,the volume fraction of ferrite obtained by DTUA is higher,the volume fractions of bainite and martensite are lower,and the average size of bainite packets is smaller in the final multi-phase microstructure. But the volume fraction of retained austenite and the carbon content of retained austenite are similar in both cases. Compared with hot-rolled TRIP steel based on DTUA without micro-alloying elements,hot-rolled Nb-V-Ti microalloyed TRIP steel based on DTUA demonstrate higher yield strength and tensile strength,but lower elongation. KEY WORDS hot rolling;TRIP steel;phase transitions;microalloying;austenite;mechanical properties TRIP(transformation induced plasticity,相变汽车用钢，其显微组织由铁素体、贝氏体和残余奥 诱发塑性)钢是一种兼具高强度、高延伸率的新型氏体等组成.其中，残余奥氏体处于亚稳状态，在 收稿日期：2012-10-22 基金项目：国家高技术研究发展计划资助项目(2007AA03Z501):新金属材料国家重点实验室自主课题(2011Z-04)第 35 卷 第 12 期 北 京 科 技 大 学 学 报 Vol. 35 No. 12 2013 年 12 月 Journal of University of Science and Technology Beijing Dec. 2013 基于动态相变的热轧 Nb-V-Ti 微合金化 TRIP钢 组织及性能 王明庆1)，李龙飞1) ，杨王玥2)，孙祖庆1) 1) 北京科技大学新金属材料国家重点实验室，北京 100083 2) 北京科技大学材料科学与工程学院，北京 100083 通信作者，E-mail: lilf@skl.ustb.edu.cn 摘 要 通过单轴热压缩试验，结合扫描电镜以及 X 射线衍射技术，研究了动态相变前奥氏体晶粒状态对基于动态相 变的热轧 Nb-V-Ti 微合金化 TRIP 钢复相组织状态及力学性能的影响. 与动态相变前奥氏体晶粒为等轴状条件下相比， 动态相变前奥氏体晶粒为拉长状条件下，动态相变得到的铁素体转变量较大，最终复相组织中贝氏体含量较少且团径较 小，马氏体含量较少，但对残余奥氏体含量及其含碳量影响不明显. 与不含微合金化元素的基于动态相变的热轧 TRIP 钢相比，Nb-V-Ti 微合金化 TRIP 钢的屈服强度和抗拉强度明显提高，而延伸率有所降低. 关键词 热轧；TRIP 钢；相变；微合金化；奥氏体；力学性能 分类号 TG142.1 Microstructure and mechanical properties of hot-rolled Nb-V-Ti microalloyed TRIP steel based on dynamic transformation of undercooled austenite WANG Ming-qing1), LI Long-fei1) , YANG Wang-yue2), SUN Zu-qing1) 1) State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China 2) School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China Corresponding author, E-mail: lilf@skl.ustb.edu.cn ABSTRACT The influence of the state of prior austenite grains before dynamic transformation on the multi-phase microstructure and mechanical properties of hot-rolled Nb-V-Ti microalloyed TRIP steel based on dynamic transforma￾tion of undercooled austenite (DTUA) was investigated by uniaxial hot compression test, scanning electron microscopy, and X-ray diffraction. In comparison with that prior austenite grains are equiaxed before DTUA, when prior austenite grains are elongated before DTUA, the volume fraction of ferrite obtained by DTUA is higher, the volume fractions of bainite and martensite are lower, and the average size of bainite packets is smaller in the final multi-phase microstructure. But the volume fraction of retained austenite and the carbon content of retained austenite are similar in both cases. Compared with hot-rolled TRIP steel based on DTUA without micro-alloying elements, hot-rolled Nb-V-Ti microalloyed TRIP steel based on DTUA demonstrate higher yield strength and tensile strength, but lower elongation. KEY WORDS hot rolling; TRIP steel; phase transitions; microalloying; austenite; mechanical properties TRIP (transformation induced plasticity，相变 诱发塑性) 钢是一种兼具高强度、高延伸率的新型 汽车用钢，其显微组织由铁素体、贝氏体和残余奥 氏体等组成. 其中，残余奥氏体处于亚稳状态，在 收稿日期：2012-10-22 基金项目：国家高技术研究发展计划资助项目 (2007AA03Z501)；新金属材料国家重点实验室自主课题 (2011Z-04) DOI:10.13374/j.issn1001-053x.2013.12.008