加热工艺对Nb-Ti微合金化高强钢的影响  

Effect of heating process on Nb-Ti microalloyed high strength steel

作　　者：梁文[1,2] 吴润 胡俊[2] 杜涛[2] 尹云洋 LIANG Wen;WU Run;HU Jun;DU Tao;YIN Yunyang(College of Materials and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Wuhan Branch of Baosteel Central Research Institute,Wuhan 430080,China)

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430081 [2]宝钢中央研究院武汉分院,湖北武汉430080

出　　处：《中南大学学报（自然科学版）》2019年第9期2063-2073,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51771139)~~

摘　　要：采用金相显微镜、透射电镜(TEM)以及电解分析等仪器和方法对不同加热工艺下,含Nb钢、含Ti钢以及Nb-Ti钢的奥氏体晶粒粒径长大规律和第二相固溶规律进行研究。研究结果表明:随着加热温度增加或保温时间延长,奥氏体晶粒粒径逐渐增大,钢中第二相析出物数量减少、粒径增大;在相同加热工艺下,Nb-Ti钢的奥氏体晶粒粒径比含Ti钢和含Nb钢的小;加热至1 200℃时含Nb钢中Nb基本全部固溶,而当加热温度升至1 300℃时,含Ti钢中仍有TiN无法固溶。Nb-Ti的复合添加使Nb元素的全固溶温度从1 200℃提高至1 250℃;当加热温度为1 150℃和1 200℃时,细小的第二相粒子TiC和NbC的固溶是造成该温度区间奥氏体晶粒粒径显著增加的主要原因。The austenite grain size growth and the second phase solid solution of the Nb bearing steel,Ti bearing steel and Nb-Ti bearing steel with different heating process were studied by optical microscope(OM),transmission electron microscope(TEM)and electrolytic analysis.The results show that with the increase of the heating temperature or the holding time,the austenite grain size increases,while the number of the second phase precipitate decreases and the size increases.At the same heating process the austenite grain size of the Nb-Ti bearing steel is smaller than that of the Ti-bearing steel and the Nb-bearing steel.At 1 200℃,the Nb is almost completely solid solution for the Nb-bearing steel,and at 1 300℃,the TiN can not be solid solution for the Tibearing steel.For the Nb-Ti bearing steel,the total solid solution temperature of the Nb element increases from 1 200℃to 1 250℃.At 1 150℃and 1 200℃,the solid solution of fine second phase precipitate is the main reason for the significant increase of the austenite grain size during heating process.

关 键 词：NB TI 奥氏体晶粒粒径 第二相析出 固溶量 

分 类 号：TF777[冶金工程—钢铁冶金]