High-Cycle Fatigue Behavior of D2 Wheel Steel under Uniaxial and Multiaxial Loading Conditions for Potential Applications in the Railway Industry

Abstract

This study investigates the fatigue damage evolution mechanisms of D2 wheel steel under high-cycle uniaxial and multiaxial loading conditions, with a focus on determining the fatigue crack growth threshold (FCGT). Uniaxial and multiaxial FCGT tests were performed on pre-cracked D2 wheel steel specimens subjected to high-frequency cyclic loading at stress ratios (R) of 0.1. The results indicate that the FCGT for D2 wheel steel under uniaxial loading conditions ranges between 8–9 MPa.m0.5, while under multiaxial loading conditions, it ranges between 6–9 MPa.m0.5. Scanning electron microscopy analysis revealed differences in the crack propagation mechanisms between the uniaxial and multiaxial tests, with cracks deviating from their path and following the microstructure in the uniaxial tests, and cracks propagating along planes of weakness in the multiaxial tests. These findings provide insights into the high-cycle fatigue behavior of D2 wheel steel under different loading conditions for potential applications in the railway industry.