Study On The Surface Decarburization Of Spring Steel50CrV4by CSP

Surface decarburization of steel material is the common problem of the thermalprocessing. The spring steel decarbonization would decrease in fatigue strength and lifelength. Laboratory simulation and mathematical model method are the main means tostudy on high temperature decarbonization of spring steel.Combined with a factory of spring steel50CrV4produced by CSP,simulated fieldconditions in the laboratory, the effect of heating temperature, holding time, heatingatmosphere, chemical composition on the spring steel decarburization50CrV4layerdepth were studied. And based on the diffusion theory and Fick’S law, the calculationmodel of decarburizing of spring steel produced by CSP in heating furnace wasestablished.The experimental results showed that, the decarburization depth increases withtemperature or holding time increasing. when the holding time is30min to60min, thereis a maximum value in decraburization depth appearing at1050℃．Compared with addedV elements and ordinary elements, sensitive Temperature of decarbonization of springsteel increases significantly. mixed atmosphere byO2+CO2+H2O+N2can effectively reducethe decarburization layer thickness.Using the mathematical model, the effect of heating temperature, holding time,heating atmosphere, chemical composition on decarburization were discussed when notconsidering the impact of the oxidation reaction. Correct theoretical calculation modelwith experimental data, improve the reliability of the model.The result of the reseach canprovide theoretical basis for the optimization of process.