冷却速率对40Cr钢凝固组织及铬元素偏析行为的影响  

Effect of cooling rate on the solidification microstructure and Cr segregation behavior of 40Cr steel

作　　者：黄胜[1] 程常桂[1] 朱家发 金焱[1] 梁泽伟 陈赢[1] 

机构地区：[1]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

出　　处：《武汉科技大学学报》2016年第4期265-268,共4页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金资助项目(51474163);湖北省自然科学基金资助项目(2013CFB329)

摘　　要：采用热模拟试验的方法获得不同冷却速率下40Cr钢凝固试样,结合SEM、EDS、ICP-AES及低倍组织检测等手段分析冷却速率对40Cr钢凝固组织及其铬元素偏析行为的影响。结果表明,采用合适的冷却速率,可以获得40Cr钢全等轴晶结构的凝固组织,其铬元素分布较均匀;随着炉管内冷却速率的提高,试样1/2高度处Cr的平均含量有所降低,凝固试样的晶粒尺寸逐渐减小、铬元素显微偏析现象得到有效改善;当炉管内冷却速率由3.83℃/min提高到8.60℃/min时,钢样横断面上凝固组织的平均晶粒面积由8.76mm2减小到2.01mm2、铬元素显微偏析度的最大偏差由0.274降为0.181。Solidification samples of 40 Cr steel at different cooling rates were prepared by thermal simulation experiments.By means of SEM,EDS,ICP-AES and macrostructure detection,the effects of cooling rates on the solidification microstructure and Cr segregation behavior of 40 Cr steel were investigated.The results show that at proper cooling rate,the full equiaxed grain can be obtained and its chromium distribution is relatively uniform.With the increase of the cooling rate in furnace,the average content of chromium at half height of samples decreases,the grain size of solidification samples gradually decreases and the microscopic segregation of chromium is effectively improved.When the cooling rate in furnace increases from 3.83℃/min to 8.60℃/min,the average grain size of solidification microstructure at the cross-section of steel sample decreases from 8.76 mm^2 to 2.01 mm^2,the maximum deviation of microscopic segregation ratio of chromium drops from 0.274 to 0.181.

关 键 词：40CR钢 冷却速率 凝固组织 铬 偏析 

分 类 号：TF777.2[冶金工程—钢铁冶金]