一般論文
鉄鋼材料の表面および内部における低サイクル疲労損傷
2012 年 78 巻 786 号 p. 161-170
詳細
2012 年 78 巻 786 号 p. 161-170
In this study, low cycle fatigue tests were conducted for carbon steel, STS410, low alloy steel, SFVQ1A and austenitic stainless steel, SUS316NG, in order to investigate surface and internal fatigue crack growth characteristics. The tests were conducted under repeated two-step variable amplitude straining conditions to appear beach marks of cracks on the fracture surface. In these tests, periodical surface removal was conducted to suppress surface fatigue cracks to be a main crack which led final fracture. STS410 specimen under surface removal test was not broken until its diameter became too small. There was a defect observed on the section of the specimen cut longitudinally. Cracks initiated from internal inclusion for SFVQ1A and SUS316NG and those fatigue lives were slightly larger under surface removal test compared to those under no surface removal tests. Internal crack growth rates calculated from beach marks were similar to those of surface cracks under the same crack driving force or J integral range, ΔJ.
