Abstract
Prevention of fatigue failure in structural parts has been an important concern in aircraft engineering for many years. The high cycle fatigue (HCF) behavior of the most important materials used for very prolonged life applications is presented, with particular attention paid to steels. Determination of long life fatigue behavior becomes extremely important for better understanding and design of the components and structures. This study presents the results of an experiment to investigate the (HCF) properties of the high strength martensitic 431 stainless steel. A constant amplitude rotating bending fatigue experiment was performed at room temperature at stress ratio R = -1 and 60 HZ. In order to evaluate the fatigue limit, 18 polished specimens were tested at 6 different loads group. In the experiment, the rotating bending fatigue life was tested using the group method, and the rotating bending fatigue limit was tested using the staircase method at 107 cycles. The S–N curve of the six sets of specimens were obtained and the results showed that the fatigue limit was 495 MPa; the ratio of the fatigue limit to tensile strength was 53%. The factors which affect the fatigue life of vi metal structures are grouped into five categories: material, structure, loading, frequency, and surface. The effects of these factors on fatigue behavior are addressed. Polished specimens surface has a higher fatigue strength. The test aims to evaluate the prolonged service life (fatigue limit) of the Type 431 steel. The fatigue ratio of 53% makes it suitable for incorporation in aerospace industrial components including structural parts.