Laser cladding in-situ nano-submicron TiC reinforced ultrafine- grained Fe-based composite layers on 42CrMo steel

摘要

In-situ nano-submicron TiC reinforced ultrafine-grained Fe-based cladding layers were prepared by lasercladding gradient particle sizes of ferrotitanium, graphite, and iron powder on the surface of 42CrMosteel. Microstructures and corrosion resistance were analyzed using X-ray diffraction, scanning electronmicroscope, and an electrochemical workstation. Results showed that the average particle size of the in-situ TiC was 0.25 μm, and ranged from 0.04 μm to 1.10 μm, with 11.0 % being on the nano scale. Themicrostructure of the cladding layer was lath martensite, and the average grain size of the cladding layermatrix was 4.08 μm, reaching the ultrafine-grained scale. The average hardness of the cladding layerwas approximately 720 HV0.2, which was 425 HV0.2 higher than that of the 42CrMo steel. Thecorrosion current density of the cladding layer was more than two times lower than that of the 42CrMosteel.