Microstructure and Fatigue of EA4T Steel in Laser Cladding Remanufacturing

EA4T steel has been widely used in the manufacture of railway axles. Laser cladding remanufacturing technology has been used to repair railway axles, and the failure behaviors of railway axles has been studied. In this work, a class of original FeCrNiMo alloy layers that contain rare-earth elements was successfully fabricated through a laser cladding technique on EA4T steel substrates. The microstructure and elemental distribution of the cladding layers were analyzed through scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA). Simultaneously, the microhardness, bond strength and fatigue properties of different samples were determined. The results indicated that the phase composition of the cladding layer was mainly martensite. The grains in the cladding layer were gradually refined with an increase in the distance from the interface, and the chemical composition distribution was more uniform. At the same time, the bonding property of the cladding layer and matrix was good, and the fatigue strength of the sample was improved.