Cyclic Behavior of Class U Wheel Steel

Abstract

In order to evaluate the material properties of Class U wheel steel under cyclic loading, low-cycle fatigue tests were conducted at room temperature on specimens taken from the rim of the wheel. The test results show that Class U wheel steel experiences significant cyclic softening at lower strains, but cyclically hardens at larger strain levels. Due to the cyclic softening at lower strain levels, the steel will plastically deform, even at stresses of about one-half of the monotonic yield strength. Quantitative fatigue properties, which can then be used to predict accurate fatigue lives of various components of wheels under complex service environments, are also obtained from the low-cycle fatigue tests.