Fatigue crack initiation and propagation in stainless steel bars under combined cyclic torsion and tension
A solution treated Austenitic stainless steel SUS316 was studied, which is of nuclear grade and commonly used in nuclear reactors. The propagation behavior of a circumferential crack in a cylindrical SUS316 stainless steel bar was studied under combinations of cyclic torsion and tension. After the initiation of microscopic flat facets from circumferential precrack of the specimen, the crack face began to twist, and then the crack propagation rate started to decrease because of the crack face sliding contact under pure cyclic torsion. The crack growth rate declined continuously with crack extension and the crack arrested at last when torsional load less than some value. However, when cyclic tension was combined with cyclic torsion, the degree of the crack face sliding contact alleviated partially and the crack propagation rate was higher than that under pure torsion. The threshold condition of fatigue crack propagation was discussed in terms of the stress intensity factor (SIF). The applied stress ranges expressed in terms of the SIF of mode I, △K1 and mode Ⅲ,△KⅢ;which were divided into three levels: no-crack growth, crack arrest and fracture. The threshold condition of fatigue crack extension was expressed by a quarter-elliptic function of the stress intensity ranges for mode I and III. The equation can be derived on the basis of the crack-tip displacement criterion. The threshold condition for fracture was also expressed by another quarterelliptic function.
Combined torsion and tension Fatigue crack growth Stainless steel Stress intensity factor Threshold
Huichen Yu Yanguo Sun Keisuke Tanaka
Testing Research Center for Aeronautical Materials, Beijing Institute of Aeronautical Materials, Bei Northern Heavy Industries Group Co., Ltd., Shenyang 110141, China Meijo University, Sinogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan
国际会议
2011 International Symposium on Structural Integrity 2011国际结构完整性学术研讨会--核工程结构完整性技术 ISSI 2011
合肥
英文
59-64
2011-10-27（万方平台首次上网日期，不代表论文的发表时间）