摘要
基于DEFORM-HT软件,对18CrNiMo7-6钢的气体渗碳工艺进行数值模拟:研究了两种不同的扩散系数模型对合金钢渗碳过程的影响,即考虑温度、碳原子的模型D(T,C)和考虑温度、合金元素、碳原子的模型D(T,M,C);并对3种不同渗碳层深度的渗碳工艺进行数值仿真以及试验验证。用机械剥层法测量3种渗碳工艺的碳含量沿深度的分布,并与仿真结果进行对比,发现采用D(T,M,C)模型的仿真精确度更高;但当渗层深度达到4 mm时,表层碳含量的试验结果与模拟相差较大,这是由于Cr、Mo等元素在长时间渗碳过程中与碳原子结合形成大量的碳化物,进而降低了碳原子的扩散系数,同时也导致试样的表层碳含量达到1.0%,高于渗碳工艺最后一段的环境碳势0.8%。
The gas carburizing process of 18CrNiMo7-6 steel was simulated based on DEFORM-HT software.Two different carbon diffusion coefficient models,the D(T,C)model considering the effect of temperature and carbon atoms as well as the D(T,M,C)model considering the combined effect of temperature alloy and carbon atoms,were compared in this study.Moreover,numerical simulation and experimental verification of three carburizing processes with different depth of carburized layer were carried out in this study.The mechanical stripping method was used to measure the distribution of carbon content along the depth under different carburizing processes,and the comparison with simulation results showed that simulation accuracy with D(T,M,C)theory was higher.However,when the case depth reaches 4mm,a big difference was appeared between the experiment and simulation results of the surface carbon content.The diffusion coefficient of carbon atoms was reduced,due to the Cr and Mo elements could easily combine with carbon atoms to form carbides in the case of long time carburizing.Meanwhile,the formation of carbides led to the high surface carbon content of 1.0%,which was higher than the ambient carbon potential(0.8%)in the last stage of carburizing process.
作者
秦盛伟
张玉芳
张棒
QIN Shengwei;ZHANG Yufang;ZHANG Bang(Henan Engineering Laboratory of Anti-fatigue Manufacturing Technology,Zhengzhou University,Zhengzhou 450001,China)
出处
《郑州大学学报（工学版）》
CAS
北大核心
2020年第2期56-60,共5页
Journal of Zhengzhou University（Engineering Science）
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)。
