Effect of hot rolling on non-metallic inclusions and fatigue behaviour of AISI: 1045 clean steel

In this research, the effect of several passes of hot rolling on characterises of non-metallic inclusions and fatigue behaviour of AISI: 1045 clean steel were investigated. Inclusions have destructive effects on fatigue properties and should be identified and removed subsequently. Therefore, hot rolling operation was carried out on the ingots with a dimension of 150 × 150 mm2 and reduction in cross section to 50%, 70%, 90%, and 99.4% were obtained in four passes of rolling, respectively. Microscopic, mechanical and fatigue investigations were performed subsequently. It was found that existence of holes consists of inclusion in failure surfaces cause to reduce the effective stress surface and increase the failure contingency. Fatigue results indicated that applying at least 90% reduction in area in hot rolling causes to improve fatigue property. It is also distinguished that great binary and ternary inclusions and fine single inclusions cause to crack initiation and crack propagation, respectively.