碳钢表面碳原子偏聚对锡原子热扩散的影响  

Effects of carbon content in carbon steel on the surface diffusion of tin

作　　者：李海斌[1] 徐惠婷 闫岳涛 陈璇 帅美荣[1] 王强[1] LI Haibin;XU Huiting;YAN Yuetao;CHEN Xuan;SHUAI Meirong;WANG Qiang(Heavy Machinery Engineering Research Center of Education Ministry,Taiyuan University of Science and Technology,Taiyuan 030024,China;School of Mechanical Engineering,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030000 [2]太原科技大学机械工程学院,山西太原030000

出　　处：《中国有色冶金》2025年第1期96-104,共9页China Nonferrous Metallurgy

基　　金：国家自然科学基金资助项目(No.51875382);山西省重点研发计划项目(202302150401003);太原市关键核心技术攻关“揭榜挂帅”项目(2024TYJB0114);忻州市重点研发计划(20240103);太原科技大学研究生创新项目(SY2023022)。

摘　　要：巴氏合金与轴承(碳钢)的紧密结合对轴承运行效率至关重要,目前主要采用铁锡化合物作为中间材料来提高轴承寿命。目前相关文献关于碳钢中碳原子含量对锡原子向铁中的扩散影响还没有报道,本研究对25^(#)和35^(#)钢基体表面进行了一系列热镀锡试验,分析了310℃条件下,Fe-Sn反应平衡时间、锡原子扩散系数和扩散厚度等关键指标对锡原子向碳钢中扩散的影响。结果表明,锡原子扩散到碳钢表面的距离随着保温时间的增加而增大,在310℃时,锡原子进入25^(#)钢的扩散系数为6.6×10^(-9),约为35^(#)钢的两倍;碳原子向25^(#)和35^(#)钢表面的扩散距离比与碳钢表面碳浓度商的平方根成反比。此外,Fe_(3)C的键能为-133 eV/atom,而FeSn和Fe_(3)Sn_(2)的键能分别仅为-7.4和-6.9 eV/atom;可知碳原子易与铁原子结合,即碳钢表面碳含量高会阻碍锡原子向钢中扩散。因此,锡原子容易向25^(#)钢表面扩散,25^(#)钢为理想的巴氏合金轴承材料。The close combination of Babbitt alloy and bearings(carbon steel) is crucial for the efficiency of bearing operation,and currently iron-tin compounds are mainly used as intermediate materials to improve bearing life.At present,there is no report in relevant literature on the effect of carbon atom content in carbon steel on the diffusion of tin atoms into iron.A series of experiments concerning hot-tin plating on the surfaces of 25 and 35 steel matrix have been carried in this paper.The key indicators involving Fe-Sn equilibrium time diffusion coefficient of Sn atoms and diffusion thickness have also been analyzed,which could be used to estimate the binding quality during the reaction process at 310 ℃.The results indicate that the distance from tin atoms diffused into the surface of carbon steel increases with the increasing of holding time,and the diffusion coefficient of tin atoms entering 25 steel is 6.6×10^(-9),which is about twice that of 35 steel at 310 ℃.The diffusion distance ratio of carbon atoms is inversely proportional to the square root of the carbon concentration quotient in the surfaces of 25 and 35 steel.In addition,the calculated bonding energy of Fe_(3)C is-133 eV/atom,while the bonding energies of FeSn and Fe_(3)Sn_(2) are only-7.4 and-6.9 eV/atom,respectively.It is obvious that carbon atoms are easily combined with iron atoms,that is,the high carbon content would hinder tin atoms to diffuse into the steel.This is the fundamental reason why tin atoms are easily diffused towards the surface of 25 steel.As a result,the matrix material of 25 steel is identified as an ideal babbitt alloy bearing material.

关 键 词：巴氏合金 轴承 铁锡化合物 碳钢 锡原子 扩散距离 扩散系数 结合能 

分 类 号：TF125.12[冶金工程—粉末冶金]