化学热处理后残余应力分布及对疲劳强度的影响

DISTRIBUTION OF RESIDUAL STRESS PRODUCED IN CHEMICAL HEAT TREATMENT AND INFLUENCE ON FATIGUE STRENGTH

探讨了渗碳、碳氮共渗、氮化等常用的化学热处理后所产生的残余应力分布特点，及其对疲劳强度的影响。试验表明，化学热处理后残余压应力的深度往往与渗层深度相一致。渗层中的相变次序和残余奥氏体的存在对残余应力分布影响较大。表层残余压力对工件的疲劳强度起着有益的作用。

The distribution feature of residual stress caused by chemical heat treatment and its influence on fatigue strength are investigated. Test shows that the depth of residual compressive after chemical heat treatment is correspondent with that of diffusion layer. Phase transformation sequence in diffusion layer and the existence of residual austenite have great effect on the distribution of residual stress.The residual compressive stress is beneficial to fatigue strength.