Nb和时效时间对热轧中锰TRIP钢中P偏聚的影响  

Effect of Nb and aging time on phosphorus segregation in hot-rolled medium-manganese TRIP steel

作　　者：李岩[1] 付吉雪 赵增武[1] 定巍[1,2] Li Yan;Fu Jixue;Zhao Zengwu;Ding Wei(Key Laboratory of Integrated Exploitation of Bayan Obo Multi-metal Resources,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,China;School of Materials and Metallurgy Engineering,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,China)

机构地区：[1]内蒙古科技大学内蒙自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010 [2]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《金属热处理》2020年第3期59-63,共5页Heat Treatment of Metals

基　　金：国家自然科学基金(51364033,51304120);内蒙古自然科学基金(2019MS05014)。

摘　　要：热轧态中锰TRIP钢首先经650℃退火2 h,随后在550℃进行等温时效热处理,采用场发射扫描电镜(FE-SEM)研究该钢中P的偏聚和时效析出行为的变化情况。结果表明,中锰TRIP钢中P在晶界的偏聚是一种非平衡偏聚现象,临界时间约为50 h,与理论计算结果48 h较为吻合。在局部偏聚区域内,C与P存在共偏聚的关系,即P偏聚量高的地方,C含量也高。而合金元素Nb具有抑制P偏聚的效果,在20~70 h时效时间内,可以相对降低6.57%~19.5%的最大P偏聚量。根据电子背散射衍射(EBSD)菊池线分析,P偏聚量低于2.28at%时,P为固溶状态,高于2.28at.%时,P为析出状态。The phosphorus segregation and precipitation behavior in a hot-rolled medium-manganese TRIP steel treated with 650℃annealing for 2 h+550℃isothermal aging were investigated by field emission scanning electron microscopy(FE-SEM).The results show that the grain boundary segregation of P is a non-equilibrium phenomenon.The critical time is about 50 h,which is consistent with the theoretical calculation result of 48 h.C and P co-segregation exists in certain local regions,where the segregations of C and P are both higher.The alloying element Nb has an inhibitory effect on phosphorus segregation in the steel,the maximum P segregation content can be reduced relatively by 6.57%-19.5%within the aging time of 20-70 h.According to the Kikuchi line analysis in the electron backscatter diffraction,P is in solid solution when the content of segregation is less than 2.28 at%,while P will be in the precipitated phase when the content of segregation is more than 2.28 at%.

关 键 词：中锰钢 等温时效 P偏聚 非平衡偏聚 临界时间 

分 类 号：TG142.3[一般工业技术—材料科学与工程]