Study On Recrystallization And Microstructure Prediction Of Spring Steel 50CrV4 Based On CSP Process

Spring steels is applied wildly in varieties of transportation,such as automobile for it excellent mechanical properties and sag-resistance.With the development of lightweight vehicles,the performance requirements of spring steels is higher.Because of advantages like fast solidification and small composition segregation,etc,the use of CSP process to produce high carbon spring steel has become an inevitable trend.By thermal simulation under different deformation conditions,this article studies the dynamic recrystallization and static recrystallization of spring steel 50CrV4 by the CSP process of Wuhan Iron and Steel and establish a corresponding application.Contents and conclusions are as follows:(1)True tress-true strain curves of single-pass thermal simulation experiments are measured to analyze the impact of factors for dynamic recrystallization with the phase diagram.The dynamic recrystallization kinetic equation are established based on the true stress-true strain curve analysis,Grain size model was established by measuring the grain size in microstructure under various conditions.(2)True tress-true strain curves of double-pass are measured by the thermal simulation experiments.Softening ratio of static recrystallization are calculated by 0.2%stress compensation method in different deformation conditions;A static recrystallization percentage model is established by analyzing the impact of factors for static recrystallization.(3)Considering the different between two-pass compression and multi-pass rolling process and using the models of dynamic recrystallization and static recrystallization based on experiments,a microstructure prediction software of medium & high-carbon spring steel 50 CrV4 based on CSP process is established.