Microstructure And Performance Study On Ti And B Doping Of High-Carbon Ferrochrome Laser Cladding Coating

High-Carbon Ferrochrome coating were successfully produced by the laser cladding at 2500W power on Q235 steel substrate. The microstructure, properties of laser cladding layers and the influence of different process parameters on it were studied. The results showed that the coating layer and the matrix had a good metal urgical combination. From the outside to the inside of the coating, they were the cladding isometric zone, cladding columnar crystal zone, combined area and the matrix respectively. XRD analysis showed that the main phases of the coating are formed by a-Fe, CrFe, ?Cr,Fe?₇C₃, Cr₇C₃. The High Carbon Ferrochrome coating showed the highest hardness and the minimal wear of coating suface, and the value were respectively 854.18HV and 1.17mg/mm² when scanned at the speed of 3.0mm/s. As the corrosion current density up to 102.7A/mm², the coating still had good corrosion resistance performance.In order to prepare better High Carbon Ferrochrome coating, different amount of Ti element was added to the High Carbon Ferrochrome. The result showed that:in the laser power for laser power 2500W, scanning speed of 2mm/s, the coating phase was mainly a-Fe, CrFe, ?CrFe?₇C₃, Cr₇C₃?TiC and Cr₂₃C₆. With the ratio of Ti increase in the coating, the average hardness of cladding layer increased first and then decreased. When the ratio of Ti was 2%, the cladding layer hardness reached 917.8HV. When the ratio of Ti reached 4%, the coating exhibited the minimal wear--1.11mg/mm². The property of corrosion resistance of the coating doped 2%Ti was the best, as the minimum corrosion current density was 517.6A/mm², and the self corrosion was-446.156mV.Compared with the dopting Ti elements alone, when adding a certain proportion of Ti and B compound, the coating phase was mainly a-Fe, CrFe,?Cr,Fe?₇C₃ Cr₇C₃ Cr₂₃C₆?TiC and BC. When the Ti B ratio is 5:1, the coating hardness reached the maximum value which was 1731HV, and moreover, the wear resistance reached up to 0.88mg/mm² which was also the optimal condition. And the minimum corrosion current is 122.1 A/mm². It was the best corrosion resistance.