A study on the hysteresis, surface temperature change and fatigue life of SM490A, SM490A-weld and FC250 metal materials

Fatigue tests were carried out at different stress levels for three kinds of metals; SM490, SM490A-weld, and FC250. During the fatigue tests, the surface temperature was measured by an infrared camera, and the hysteresis was calculated afterward. It was found that the hysteresis and surface temperature change (ΔTS) had a linear relationship. Like the previous study of the authors, it was found that the logarithm of the fatigue life was linearly proportional to the square root of Jc times the hysteresis. Using a linear relationship between the hysteresis and ΔTS, this equation was modified with the hysteresis replaced with ΔTS.