加热条件与混合气氛对50CrV4钢表面脱碳的影响

Effects of heating condition and mixing atmosphere on surface decarburization of 50CrV4 steel

试验过程模拟武钢CSP均热炉的加热条件,分别研究加热温度、保温时间、炉内气氛对弹簧钢50CrV4表面脱碳的影响规律。结果表明,50CrV4钢脱碳厚度随保温时间的延长而增加;保温时间为30和60min,加热温度低于1050℃时,脱碳层厚度随温度升高而增加,高于1050℃时,脱碳层由于氧化加剧而减少,1050℃为脱碳敏感温度;O_2+CO_2+H_2O+N_2混合气氛比O_2+CO_2+N_2和H_2O+N_2降低脱碳层厚度更加明显。结合氧化模型和菲克第二定律,建立并修正了脱碳计算模型,利用试验数据验证其可靠性。

An experiment simulating the heating environment of CSP furnace was performed to study the effects of heating temperature,holding time and heating atmosphere on the decarburization of 50 CrV4 spring steel.The results show that the decarburization layer depth of 50 CrV4 steel increases with increasing the holding time.With holding time of 30 and 60 min,the decarburization layer depth increases with increasing the heating temperature below 1 050℃ and decreases when the temperature is over 1 050℃.The decarburization layer depth reaches the peak at 1 050℃.The mixed atmosphere of O_2＋CO_2＋H_2O＋N_2 can effectively reduce the decarburization layer depth more than that of O_2＋CO_2＋N_2 and H_2O＋N_2.Combined with the oxidation model and Fick＇s Second Law,the decarburization calculation model is established and corrected with experimental data.