Effect of Rare Earth on Microstructure and Performance of Laser Cladding EA4T Axle

EA4T steel was Laser cladding remanufactured by adding La and Ce mixed rare earth powder to FeCrNiMo powder. The microstructure of the cladding layer was observed by using SEM, EDS, XRD and other methods, and the remanufactured samples were tested by tensile test. The results show that the microstructure of FeCrNiMoRE alloy powder remanufactured samples is mainly composed of lath martensite, austenite and carbide in the cladding area. In the cladding zone, La and Ce are evenly distributed in grain boundaries and crystals, and form rare earth inclusions with O, C, S, etc., which act as heterogeneous nucleation particles of carbides and play a role in refining grains. Therefore, the tensile strength is 932 MPa and yield strength is 735 MPa of the remanufactured sample. They were improved 12.56% and 9.7% higher than that of the substrate, respectively. Generally, the elongation and reduction of section were similar to that of the matrix.