csp生产50crv4弹簧钢脱碳行为的分析word格式论文.docxVIP

优秀毕业论文 精品参考文献资料 Abstract Surface decarburization of steel material is the common problem of the thermal processing. The spring steel decarbonization would decrease in fatigue strength and life length. Laboratory simulation and mathematical model method are the main means to study on high temperature decarbonization of spring steel. Combined with a factory of spring steel 50CrV4 produced by CSP,simulated field conditions in the laboratory, the effect of heating temperature, holding time, heating atmosphere, chemical composition on the spring steel decarburization 50CrV4 layer depth were studied. And based on the diffusion theory and Fick’S law, the calculation model of decarburizing of spring steel produced by CSP in heating furnace was established. The experimental results showed that, the decarburization depth increases with temperature or holding time increasing. when the holding time is 30min to 60min, there is a maximum value in decraburization depth appearing at 1050℃．Compared with added V elements and ordinary elements, sensitive Temperature of decarbonization of spring steel increases significantly. mixed atmosphere byO2+CO2+H2O+N2 can effectively reduce the decarburization layer thickness. Using the mathematical model, the effect of heating temperature, holding time, heating atmosphere, chemical composition on decarburization were discussed when not considering the impact of the oxidation reaction. Correct theoretical calculation model with experimental data, improve the reliability of the model.The result of the reseach can provide theoretical basis for the optimization of process. Keywords: Surface decarburization; mathematical model; 50CrV4 spring steel;CSP heating furnace II 目 录 摘 要................................................................................................................................... I Abstract................................................................................................................................ II