Low-cycle fatigue of Fe-20%Cr alloy processed by equal- channel angular pressing

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Kaneko, Yoshihisa^1 ; Tomita, Ryuji^1 ; Vinogradov, Alexei^2

Department of Mechanical Engineering, Osaka City University, Osaka 558-8585, Japan^1

Laboratory for the Physics of Strength of Materials and Intelligent Diagnostic Systems, Togliatti State University, Togliatti 445667, Russia^2

关键词: Average grain size;    Ferritic stainless steel;    Low angle grain boundaries;    Low cycle fatigue properties;    Low cycle fatigues;    Low-cycle fatigue tests;    Strain controlled fatigue;    Stress amplitudes;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012160/pdf
DOI  :  10.1088/1757-899X/63/1/012160

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Low-cycle fatigue properties were investigated on Fe-20%Cr ferritic stainless steel processed by equal channel angular pressing (ECAP). The Fe-20%Cr alloy bullets were processed for one to four passes via Route-Bc. The ECAPed samples were cyclically deformed at the constant plastic strain amplitude pl of 5x10-4at room temperature in air. After the 1-pass ECAP, low-angle grain boundaries were dominantly formed. During the low-cycle fatigue test, the 1-pass sample revealed the rapid softening which continued until fatigue fracture. Fatigue life of the 1-pass sample was shorter than that of a coarse-grained sample. After the 4-pass ECAP, the average grain size reduced down to about 1.5 μm. At initial stage of the low-cycle fatigue tests, the stress amplitude increased with increasing ECAP passes. At the samples processed for more than 2 passes, the cyclic softening was relatively moderate. It was found that fatigue life of the ECAPed Fe-20%Cr alloy excepting the 1-pass sample was improved as compared to the coarse-grained sample, even under the strain controlled fatigue condition.