渗碳化学热处理合金钢晶粒长大的元胞自动机模拟  

Cellular Automaton Modeling of Grain Growth during Carburization Chemical Heat Treatment of Alloy Steels

作　　者：王燕 袁岳东 沈鑫珺 薛雨 刘琨 张庆宇 Wang Yan;Yuan Yuedong;Shen Xinjun;Xue Yu;Liu Kun;Zhang Qingyu(School of Iron and Steel,Soochow University,Suzhou 215137;Changshu Tiandi Coal Machinery Equipment Co.,Ltd.,Suzhou 215500,China)

机构地区：[1]苏州大学沙钢钢铁学院,江苏苏州215137 [2]常熟天地煤机装备有限公司,江苏苏州215500

出　　处：《广东化工》2022年第20期41-43,19,共4页Guangdong Chemical Industry

基　　金：苏州大学大学生创新创业训练计划(项目编号202110285123Y);国家自然科学基金(资助号:51901148、51904072)。

摘　　要：针对重载齿轮用18Cr2Ni4W合金钢的渗碳化学热处理过程,本研究建立了元胞自动机模型并对奥氏体的晶粒长大现象和碳化物对晶界的钉扎作用进行模拟研究。开展了18Cr2Ni4W合金钢保温实验并观察晶粒大小,发现数值模拟结果与实验观察结果具有较好的一致性。模拟和实验结果表明,随着保温时间的增加,平均晶粒尺寸增加,且温度越高,晶界迁移率越高,晶粒长大速率也越快。模拟再现了奥氏体晶粒长大过程中碳化物对晶界有钉扎作用,对碳化物阻碍晶界迁移和晶粒继续长大进行了可视化分析。本研究能够预测和再现不同渗碳温度时奥氏体晶粒尺寸的演化规律,为减少实验次数、降低渗碳工艺研发成本提供有力工具。With respect to the carburization process of an 18Cr2Ni4W alloy steel for heavy-duty gears, a cellular automaton model is proposed for the simulations of the austenite grain growth and the pinning effect of carbides. In the numerical simulation of austenite grain growth, the growth processes of austenite grains at different temperatures are studied. The austenite grain growth experiments are carried out, and it is found that the simulation results are in good agreement with the experimental observations. The results show that with the increase of carburizing time, the average grain size increases. As the temperature becomes higher,the grain boundary mobility increases, so that the grains grow faster. During the growth of austenite grains, the existence of carbides at the grain boundaries have a pinning effect on the austenite grain boundaries, which could hinder the migration of grain boundaries and the continuous growth of grains. This study could not only prediction the size of austenite grains under different conditions, but also provide scientific tools for reducing the number of experiments and thus the R&D costs for carburization of alloy steels..

关 键 词：化学热处理 渗碳 晶粒长大 碳化物 元胞自动机 

分 类 号：TD421.6[矿业工程—矿山机电]