Nb-Mo微合金化对δ-TRIP钢组织和力学性能的影响  

Effect of Nb-Mo microalloying on microstructure and mechanical properties of δ-TRIP steel

作　　者：洪济舟 宋双喜[1] 王俊峰 王利[2,3] 王晓东 Hong Jizhou;Song Shuangxi;Wang Junfeng;Wang Li;Wang Xiaodong(School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Research Institute,Baoshan Iron and Steel Co. ,Ltd. ,Shanghai 201900,China;State Key Laboratory of Development and Applicaton Technology of Automotive Steels ( Baosteel) ,Shanghai 201900,China)

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]宝山钢铁股份有限公司研究院,上海201900 [3]汽车用钢开发与应用技术国家重点实验室(宝钢),上海201900

出　　处：《金属热处理》2019年第5期1-6,共6页Heat Treatment of Metals

基　　金：上海市自然科学基金(17ZR1415000);国家重点研发计划重点专项(2017YFB0703000)

摘　　要：采用SEM、TEM、EBSD等分析了Nb-Mo微合金化对δ-TRIP钢力学性能、组织结构的影响。结果表明:Nb-Mo微合金化试验钢及对照钢均为复相组织,主要由δ铁素体、贝氏体、α铁素体和残留奥氏体等构成。添加微量Nb-Mo元素后,试验钢组织中残留奥氏体含量略有增加,同时伴随着大量纳米级Nb-Mo碳化物析出;并且试验钢的力学性能明显改善,其抗拉强度达到1044 MPa,伸长率为22. 4%。微观组织表征结果表明:其主要强化机制为残留奥氏体的相变诱发塑性(TRIP)效应以及纳米尺寸Nb、Mo碳化物通过钉扎晶界和位错,从而达到细晶强化和第二相颗粒强化。The influence of Nb-Mo microalloying on the mechanical property and microstructure of δ-TRIP steel was analyzed by scanning electron microscope( SEM),transmission electron microscope( TEM),electron back-scattered diffraction( EBSD).The result indicates that the microstructure of both the steels with and without Nb-Mo microalloying contain delta-ferrite,bainite,alpha-ferrite and retained austenite phases.After adding trace Nb-Mo,the volume fraction of retained austenite slightly increases and a mass of nano-size Nb-Mo carbides precipitate out.Further,the mechanical properties of the Nb-Mo steel are signally promoted with the tensile strength of 1044 MPa and the elongation of 22.4%.The microstructure characterization shows that the major strengthening mechanisms of the Nb-Mo microalloying steel are the transformation-induced plasticity( TRIP) effect of retained austenite,as well as the fine-grain strengthening and second-phase strengthening caused by Nb-Mo carbide pinning grain boundaries or dislocations.

关 键 词：δ-TRIP钢 微合金化 性能 组织 纳米析出相 

分 类 号：TG142.13[一般工业技术—材料科学与工程]