闭塞冷锻星形套的组织、残余应力及性能研究

Study on Microstructure Residual Stress and Performance of Starlike Inner Race Produced by Cold Closed Die Forging

针对经闭塞冷锻成型的星形套的组织、残余应力、位错密度及硬化规律进行了试验研究。结果表明,星形套冷锻件显微组织正常,锻件成型时受3向压应力作用,表层的残余应力将对腐蚀开裂、脆性断裂的抑制及疲劳强度的提高起一定作用。分析了宏观残余应力分布不均的原因,提出了冷模锻模具改进的方案,并用位错理论解释了其硬化的原因。

Tests and researches are conducted for microstructure,residual stress,dislocation density and hardening principle of starlike inner race formed by cold closed die forging method.It is shown by test result that the microstructure of starlike inner race cold forging part is normal,under action of three-way pressing stress due to forming of forging part,the residual stress in the case of forging part shall play a certain role to prohibit the corrosion crack and brittle rupture and increase the fatigue strength.The paper analyzes the causes of non-homogeneous distribution of macro-residual stress and puts out the improvement schedule of dies in cold die forging,explains its hardening causes by dislocation theory.