Characterizing How Different Modes of Corrosion Exposure Impact Fatigue Testing Results on 4340 HSS Steel

Abstract Assessing the relationship between corrosion and fatigue performance on steel has historically been executed under immersion conditions. However, it is known that corrosion under immersive conditions does not accurately represent the damage modes observed with atmospheric exposure. To address this deficiency, 4340 HSS fatigue bars were exposed to natural environments, outdoor accelerated conditions, immersion, and wet to dry cycling test methods to understand how the resulting corrosion damage influenced the follow-on fatigue testing. This paper demonstrates the need for new combined effects test methodologies which can assess how the onset and propagation of corrosion can influence fatigue test results to more closely represent real service conditions.