Low cycle fatigue characteristics and life prediction of 316LN austenitic stainless steel  

作　　者：Kailun Ding Zhengxin Tang Xikou He Xitao Wang Jinshan He 

机构地区：[1]Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing,100083,China [2]Research Institute of Special Steels,Central Iron and Steel Research Institute Co.,Ltd,Beijing,100081,China [3]Shandong Provincial Key Laboratory for High Strength Lightweight Metallic Materials,Advanced Materials Institute,Qilu University of Technology(Shandong Academy of Science),Jinan,250353,China

出　　处：《Progress in Natural Science:Materials International》2024年第6期1194-1206,共13页自然科学进展·国际材料(英文版)

基　　金：supported by the financial support from Special fund for independent research and development of Central Iron and Steel Research Institute (No. 21T62610B);the Fundamental Research Funds for the Central Universities (No. FRF-BD-23-01);the financial support from Special fund for independent research and development of Iron and Steel Research Institute Co.,Ltd (No. 23T60170Z)

摘　　要：An investigation was conducted on the low cycle fatigue behavior,fatigue life,and fatigue fracture mechanism of forged 316LN stainless steel at 330°C,under varying strain amplitudes.The results indicate that the cyclic softening degree of 316LN austenitic stainless steel increases proportionally with the strain amplitude.This increase can be attributed to variations in the arrangement and development process of the dislocation structure.Additionally,it was observed that both back stress and friction stress augment as the total strain amplitude increases.This phenomenon is primarily caused by enhanced interactions between dislocations and precipitated phases,as well as dislocations themselves.The hysteresis loop area exhibits an increase in direct correlation with the total strain amplitude.Moreover,a smaller strain amplitude corresponds to reduced plastic strain energy and increased fatigue life.In engineering applications,the simplicity and universality of a model,along with easily obtainable parameters,are crucial considerations.To evaluate the fatigue life of 316LN austenitic stainless steel,four models were employed:Coffin-Manson fatigue life model,energy life model,three-parameter power model,and three-parameter power life correction model.The predicted data from the three-parameter power life correction model fell within the acceptable error range of 1.2,demonstrating a strong alignment with the experimental values.Consequently,it can be concluded that the three-parameter power life correction model exhibits remarkable accuracy in predicting low cycle fatigue(LCF)behavior,thereby facilitating the safety assessment of component lifespan.The fatigue fracture surface exhibits distinct features of fatigue striations,with a noticeable decrease in the interval between these striations as the total strain amplitude increases.

关 键 词：316LN austenitic stainless steel Low cycle fatigue Fatigue life Cyclic hardening and softening Fatigue striation 

分 类 号：TG142.71[一般工业技术—材料科学与工程]