锡原子在碳钢表面的热扩散分析  

Thermal Diffusion Analysis of Tin Atom on Carbon Steel Surface

作　　者：李海斌[1] 帅美荣[1] 王强[1] LI Haibin;SHUAI Meirong;WANG Qiang(Heavy Machinery Engineering Research Center of Education Ministry,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学重型机械教育部工程研究中心,山西太原030024

出　　处：《热加工工艺》2020年第20期116-120,共5页Hot Working Technology

基　　金：山西省重点研发计划项目(201903D121043);太原科技大学博士启动金项目(20182006)。

摘　　要：研究了310℃时液态锡向25、35钢表面的热扩散行为。结果表明:随时间的增加,进入碳钢表面的锡原子扩散层厚度增大。活化锡原子与25钢、35钢基体铁原子的反应速率(k)分别为0.153、0.0956 min-1,为准一级反应。随着锡原子扩散量的增加,扩散层系统化学势(-Δμ)逐渐减小,稳定性降低。25钢界面的化学势(-Δμ)远低于35钢,锡原子易于向25钢表面扩散;锡原子的扩散驱动力随化学势的降低而降低,说明锡原子沿其浓度降低方向扩散。含碳量高的35钢中含有性能稳定的渗碳体(珠光体)较多,抵消了锡原子向35钢扩散的较大驱动力。The thermal diffusion behavior of tin atoms on the surface of 25 steel and 35 steel at 310 ℃ was studied. The results show that the thickness of the diffusion layer increases with the time increasing. The reaction rate(k) of activated tin atom with iron atom of 25 steel and 35 steel is 0.153 min-1 and 0.0956 min-1, respectively, which is quasi first order reaction.With the increase of tin diffusion, the chemical potential(-Δμ) of the diffusion layer system decreases and the stability decreases. The chemical potential(-Δμ) of the interface of 25 steel is much lower than that of 35 steel, and the diffusion of tin atom to the surface of 25 steel is easy. The driving force of the diffusion of tin atom decreases with the chemical potential increasing, which indicates that the diffusion of tin atom is in the direction of its concentration decreasing. There are more stable cementite(pearlite) in 35 steel with high carbon content,which counteracts the larger driving force of tin atom diffusion to 35 steel.

关 键 词：锡原子 反应级数 化学势 

分 类 号：TG111.6[金属学及工艺—物理冶金]