摘要
45Cr9Si3钢是应用广泛的中碳马氏体气阀钢,钢中碳化物的形态、数量、大小和分布对45Cr9Si3钢的性能有重要影响。借助金相显微镜、扫描电镜、三维腐刻仪及能谱分析仪对某厂45Cr9Si3模铸坯中碳化物类型、形态及分布情况进行解析,使用Thermo-Calc 2020b热力学软件计算45Cr9Si3马氏体气阀钢的相转变和碳化物析出行为。结果表明,45Cr9Si3马氏体气阀钢碳化物类型为富Cr的M_(7)C_(3)型碳化物和富Nb的MC型碳化物;铸坯中碳化物形貌主要可以分为4类:颗粒状碳化物、块状碳化物、长条状碳化物和聚集网状碳化物。颗粒状碳化物尺寸为3~5μm,块状碳化物尺寸在10~15μm之间,长条状碳化物尺寸约为20~50μm,聚集网状碳化物由颗粒状、块状、长条状碳化物聚集形成,其尺寸达70~120μm。从边部到心部碳化物形态的演变规律为:颗粒状→块状→长条状→网状,从边部到心部碳化物不均匀性逐渐增强,边部碳化物以颗粒状和块状为主,1/4中心处碳化物呈长条状,心部碳化物呈网状结构;从边部到心部碳化物的平均等效直径由10.2μm增长到17.1μm,面积比例由0.86%增长到1.48%,碳化物的密度由边部的72个/mm^(2)下降到心部的43个/mm^(2)。
45Cr9Si3 steel is a widely used medium carbon martensitic valve steel.The form,quantity,size,and distribution of carbides in the steel have an important effect on the performance of 45Cr9Si3 steel.The type,shape,and distribution of carbides in the 45Cr9Si3 mold casting billet of a factory were analyzed using a metallographic microscope,scanning electron microscope,three-dimensional etching instrument,and energy spectrum analyzer.The phase transition and carbides precipitation behavior of 45Cr9Si3 martensitic valve steel were calculated by Thermo-Calc 2020b thermodynamic software.The results show that the carbides of 45Cr9Si3 martensitic valve steel are Cr-rich M_(7)C_(3)carbides and Nb-rich MC carbides.The carbides morphology in the casting billet can be divided into four categories:granular carbides,massive carbides,long strip carbides,and clustered network carbides.The size of granular carbide is 3-5μm,the size of massive carbide is between 10-15μm,and the size of long strip carbide is about 20-50μm.The aggregate network carbide is formed by the aggregation of granular,massive,and long strip carbides,and its size is 70-120μm.The morphology of carbide from edge to core is as follows:granular→massive→long strip→network.The non-uniformity of carbide from the edge to core is gradually enhanced.The carbide from the edge to core is mainly granular and massive,the carbide in the center of 1/4 is long strip,and the carbide in the core is a network structure.The average equivalent diameter of the carbides from the periphery to the center increased from 10.2 to 17.1μm,the area proportion rose from 0.86%to 1.48%,and the density of carbides decreased from the 72 mm^(-2)at the side to 43 mm^(-2)at the core.
作者
季灯平
黄宗瑗
宋光洁
徐翔宇
付建勋
JI Dengping;HUANG Zongyuan;SONG Guangjie;XU Xiangyu;FU Jianxun(Center for Advanced Solidification Technology(CAST)of School of Materials Science and Engineering,Shanghai University,State Key Laboratory of Metallurgy and Preparation of High-Quality Special Steel,Shanghai 200444,China;Zhejiang Qingshan Iron and Steel Co.,Ltd.,Lishui 325000,Zhejiang,China)
出处
《钢铁研究学报》
北大核心
2025年第7期910-918,共9页
Journal of Iron and Steel Research
基金
国家自然科学基金资助项目(52074179)。
作者简介
季灯平(1981-),男,博士,E-mail:dpji@163.com;通信作者:付建勋(1969-),男,教授,E-mail:fujianxun@shu.edu.cn。
