18CrNiMo7-6钢渗碳淬火后回火过程的数值模拟研究  

Research on Numerical Simulation of Tempering Process of 18CrNiMo7-6 Steel after Carburizing and Quenching

作　　者：秦盛伟 赵辉辉 QIN Shengwei;ZHAO Huihui(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学机械与动力工程学院,河南郑州450001

出　　处：《热加工工艺》2024年第22期124-128,133,共6页Hot Working Technology

基　　金：国家自然科学基金联合基金重点项目(U1804254);河南省科技攻关项目(192102210012)。

摘　　要：基于Deform-HT软件,考虑了回火时马氏体、残余奥氏体的分解对组织场、应力场和硬度场的影响,对18CrNiMo7-6合金钢渗碳淬火后的回火工艺进行数值模拟。为了确定马氏体分解模型中的参数,制备了0.21%C和0.80%C两种不同碳含量的全渗透试样并进行膨胀试验,根据膨胀试验,计算不同碳含量试样在JMAK方程中的参数;根据JMatPro软件,计算残余奥氏体分解模型中的参数。模拟了试样渗碳淬火后在200、400℃回火3 h后组织场、应力场的变化。结果发现,随着回火温度的升高,残余奥氏体以及马氏体的转变量均显著增大,残余应力显著降低。同时,建立了能够适用于预测18CrNiMo7-6钢在渗碳淬火后的回火过程的硬度变化模型。Based on Deform-HT software,considering the influence of the decomposition of martensite and retained austenite on the microstructure,stress and hardness fields during tempering,the tempering process of 18CrNiMo7-6 alloy steel after carburizing and quenching was numerically simulated.In order to determine the parameters of martensite decomposition model,two kinds of full penetration specimens with different carbon contents(0.21%C and 0.80%C)were prepared and subjected to the expansion test.According to the expansion test,the parameters of different carbon content samples in the JMAK equation were calculated,and according to the JMatPro software,the parameters in the decomposition model of retained austenite were calculated.The changes of the microstructure field and stress field by tempering at 200℃and 400℃for 3 h after carburizing and quenching were simulated.The results show that with the increase of tempering temperature,the transformation amount of retained austenite and martensite increases significantly,and the residual stress decreases significantly.At the same time,a hardness change model can be established to predict the tempering process of 18 CrNiMo7-6 steel after carburizing and quenching.

关 键 词：回火 马氏体分解 残余奥氏体分解 硬度模型 

分 类 号：TG161[金属学及工艺—热处理]