Low Cycle Fatigue Behavior of Steam Generator Tubes under Axial Loading

Materials

Yuebing Li¹  Wei Tian¹  Weiya Jin¹  Xing He¹  Junfeng Chen¹ 

[1] Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou 310032, China;

关键词: steam generator tube;    fatigue life;    Inconel 690;    cyclic stress–strain response;   

DOI  :  10.3390/ma11101944

来源: DOAJ

【 摘 要 】

Compared with the fatigue properties of the material (Inconel Alloy 690), the real fatigue lives of tubes are more meaningful in the fatigue design and assessment of steam generator (SG) tube bundles. However, it is almost impossible to get a satisfactory result by conducting fatigue tests on the tube directly. A tube with a uniform and thin wall easily fails near the clamping ends under cyclic loading due to the stress concentration. In this research, a set-up for fatigue tests of real tubes is proposed to overcome the stress concentration. With the set-up, low cycle fatigue tests were conducted in accordance with an existing fatigue design curve for Alloy 690. Strain control mode was applied with fully reversed push–pull loading under different strain amplitudes (0.15%, 0.2%, 0.3%, and 0.4%). A favourable result was obtained, and the low cycle fatigue behavior was investigated. The results showed that the fatigue life tested by the real tube was below the strain–life curve of Alloy 690 which was fitted by conventional solid specimens. A cyclic hardening behavior was found by the cyclic stress–strain curve when compared with the monotonic stress–strain curve.

【 授权许可】

Unknown