摘要
为解决17CrNiMo6机车牵引齿轮在热处理工艺中出现的晶界氧化超标问题,通过相关的热力学计算,阐述了晶界氧化(IGO)的产生机理;采用BBH型前室预抽真空多用炉、金相和硬度检验对该齿轮进行了热处理工艺实验,并对产生晶界氧化的部位取样进行显微电镜光学扫描和能谱分析。能谱分析结果表明:晶界氧化产生的黑色网状物的主要成分是Cr和O,减少Cr氧化物的生成量可以降低晶界氧化的程度。分析Fe、Cr和氧化性气氛的平衡曲线,找出了影响Cr氧化物生成的渗碳工艺参数(加热期的均温速度,强渗期和扩散期的温度、碳势、保温时间),优化工艺使齿轮的晶界氧化程度很好地达到了技术要求。
In order to solve the serious problem of intergranular oxidation （IGO） arised in the heat treatment process of traction gear of locomotive, the mechanism of intergranular oxidation （IGO） was explained with some thermodynamic calculations relatively, then the heat treatment process experiment of traction gear was carried out with BBH multi-purpose furnace of forvacuum prechamber, metallographic examination and hardness testing. SEM and EDS were done on the sample of places that had led to a phenomenon of IGO. The results of EDS show that Cr and O are the major components of black networks produced by the IGO and the IGO＇s level can be decreased by the reduction of Cr oxide. Through the analysis of equilibrium curves about Fe, Cr and oxidizing atmospheres, those carburized process parameters, including uniform temperature velocity of hearing＇s period, temperature, carbon potential, holding time of carbon restoration and diffusion period, are found that have an effect on Cr oxide＇s generation, and then the process is optimized to reach the technical requirement degree of IGO very well.
出处
《热加工工艺》
CSCD
北大核心
2014年第4期153-157,共5页
Hot Working Technology
基金
国家科技部国际科技合作项目(2010DFB83240)
关键词
机车牵引齿轮
晶界氧化
工艺优化
渗碳
traction gear of locomotive
intergranular oxidation
process optimization
carburization
作者简介
石万凯（1968-），男，重庆人，教授，从事新型齿轮传动和表面工程研究：电话：023—65112478；E-mail：wankai—shi@cqu．edu．ca
韩振华（1986-），男，山东菏泽人，硕士研究生，从事新型齿轮传动和热处理工艺研究：电话：18716424055；E—mail：hanzhen86hua@163．com
