论文部分内容阅读
以Cr25Ni35Nb和Cr35Ni45Nb炉管钢为研究对象,以菲克第二定律和“平衡常数法”为理论基础,采用有限差分数值方法,实现了这两种高Cr-Ni裂解炉管材料高温渗碳时碳的扩散和碳化物析出的模拟,给出了渗层的总碳含量、基体中的碳含量、基体中合金元素含量在不同渗碳时间沿壁厚的分布。在1000℃对两种材料进行了固体渗碳实验,分析比较了高温下两种材料的渗碳动力学规律。结果表明,浓度场模拟结果与实验测量值吻合较好。从渗碳增重曲线和浓度场模拟结果可以看出,Cr35Ni45Nb钢的抗渗碳能力强于Cr25Ni35Nb钢。
Taking Cr25Ni35Nb and Cr35Ni45Nb furnace tube steel as the research object, using Fick’s second law and “equilibrium constant method ” as the theoretical basis, the finite difference numerical method was used to realize the high temperature seepage of the two high Cr-Ni cracking furnace tube materials Carbon carbon diffusion and carbide precipitation simulation, given the total carbon content of the diffusion layer, the carbon content of the matrix, the matrix alloy content at different carburizing time distribution along the wall thickness. The solid carburizing experiments were carried out on the two materials at 1000 ℃. The carburization dynamics of the two materials were analyzed and compared. The results show that the simulation results of concentration field are in good agreement with the experimental ones. From the carburizing weight gain curve and concentration field simulation results can be seen, Cr35Ni45Nb steel anti-carburizing ability stronger than Cr25Ni35Nb steel.