快速加热对低碳微合金钢相变和微观组织的影响  

Effects of rapid heating on phase transition and microstructure of a low-carbon microalloyed steel

作　　者：任杰 袁清[1,2,3] 莫家璇 张志成 唐恩 徐光 Ren Jie;Yuan Qing;Mo Jiaxuan;Zhang Zhicheng;Tang En;Xu Guang(State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China;Research Institute of Iron and Steel,Daye Special Steel Co.Ltd.,Huangshi 435001,China;College of Optoelectronic Manufacturing,Zhejiang Industry and Trade Vocational College,Wenzhou 325000,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [3]大冶特殊钢有限公司研究院,湖北黄石435001 [4]浙江工贸职业技术学院光电制造学院,浙江温州325000

出　　处：《武汉科技大学学报》2023年第6期401-408,共8页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金项目(52004193);中国博士后科学基金项目(2022M710596)。

摘　　要：通过热模拟实验,在5~120℃/s加热速率下对低碳微合金钢进行奥氏体化处理。根据膨胀量-温度曲线、微观组织、母相奥氏体晶粒和第二相颗粒表征结果,研究了加热速率对低碳微合金钢相变和组织演变的影响规律。结果表明,随着加热速率的增加,钢的A_(c1)、A_(c3)温度显著升高,奥氏体相变区间收窄,铁素体+珠光体转变在更高温度下进行。高加热速率导致未回溶的第二相NbC颗粒体积分数和亚结构缺陷增多,从而提升了综合强化效果。此外,奥氏体化温度对冷却过程中相变的影响程度大于保温时间,故优先采用较低的奥氏体化温度有助于细化母相奥氏体晶粒。综上所述,快速加热技术可促进初始奥氏体组织的细化和晶粒均匀化,证实了其在制备微/纳米超细晶钢工艺上潜在的应用价值。Through thermal simulation experiments,the austenitization of low-carbon micro-alloyed steel under heating rates of 5 to 120℃/s were conducted.By analyzing the expansion increment-temperature curves,optical microstructure,parent-phase austenite grains,and second-phase particles,the effects of heating rate on phase transition and microstructural evolution were studied.The results indicate that as the heating rate increases,the A_(c1) and A_(c3) temperatures of the steel significantly rise,the austenite phase transition interval narrows,and the ferrite+pearlite transition occurs at higher temperatures.Higher heating rates lead to an increase in un-dissolved second-phase NbC particles and sub-structure defects,providing an integrated strengthening effect.Furthermore,the austenitizing temperature affects the phase transition more than the equalizing time,and prioritizing a lower austenitizing temperature aids in refining parent-phase austenite grains.In summary,rapid heating promotes structural refinement and uniformity of austenite grains,confirming its potential applicability in the preparation of micro/nano ultra-fine grain steel.

关 键 词：超细晶钢 快速加热 奥氏体化 相变 细晶强化 第二相析出 

分 类 号：TG156.1[金属学及工艺—热处理]