摘要
本文针对合金钢气体渗碳提出了两个新参量:碳化物极限值与碳势门槛值。碳化物极限值是指某些合金钢超饱和渗碳渗层碳化物体积百分数极限值。它是钢的化学成分、气氛碳势及渗碳温度的函数。碳势门槛值是指合金钢工件在给定介质中于给定温度渗碳时,工件表面在规定时间开始出现碳化物的气氛碳势。与渗氮相似,每种合金钢在任一给定温度恒温渗碳,都可以测出一条碳势门槛值曲线。提供与这两个参量有关的曲线及数据,将有助于渗碳工艺的优化。
Two new concepts about gas carburization of alloy steel,carbideextreme value(CEV)and carbon potential threshold(CPT),are proposed.TheCEV is the maximum of the volume percentage carbide in carburized layerfor some alloy steel during super saturated carburizing.It varies with thechemical composition of steel,carbon potential of atmosphere and carburizingtemperature.The CPT is the carbon potential that carbide begins to precipitateon the surface of the workpiece within a given time during carburizing ingiven medium and temperature.Similar to that of nitriding potential thresholdduring nitriding,the curves of CPT can be determined for every kind ofalloy steel when they are carburized at given temperature.The curves anddatum about CPT and CEV are beneficial to optimizing carburizing process.
关键词
气体渗碳
碳化物
极限值
碳势
gas carburization
carbide extreme value(CEV)
carbon potential threshold(CPT)
