Behavior of Rotating-Bending Fatigue Failure of AF1410 Steel
HAN Shun1，LI Yong1，WANG Chun-xu1，LIU Xian-min1，LI Jian-xin2
（1. Institute for Structural Materials, Central Iron and Steel Research Institute， Beijing 100081, China 2. Fushun Special Steel Co., Ltd., Fushun 113001, Liaoning, China）
Abstract：High-cycle rotating-bending fatigue properties of high clean ultra-high strength steel AF1410 melted by VIM+VAR were investigated, and then the effect of nonmetal inclusion on fatigue properties in steel systematically was analyzed by mechanical test, analysis of microstructure and SEM of fractures. The results show that, after temper 5 hours at 510℃, AF1410 steel has excellent combined mechanical properties. Rotating-bending fatigue limit of the AF1410 steel reaches to 826MPa. By SEM of fractures, all the crack origins of fatigue stem from process flaws such as cutting marks, fine break. The main reason to lead to crack growth is stress concentration caused by surface flaw. One small and round non-metallic inclusion including La appears in the fractures of high clean steel AF1410 because of the addition of La. However, these inclusions can’t be the crack origins of fatigue.
2013, Vol. 48 
