Design, fabrication, microstructure and properties of in-situ synthesized TiC reinforced stainless steel matrix composite coating by laser cladding

TiC particle reinforced Fe-based composite coatings have excellent properties, which are broadly considered as promising high-performance coatings/components. In this study, we designed and fabricated in-situ synthesized TiC reinforced stainless steel matrix composite (SMC) coatings through adding Cr3C2 and Ti powders and subsequently carried out by laser cladding technique. Experimental results show that TiC particles are uniformly distributed within the dendrites. Based on the microstructure observation, thermodynamics calculations and dynamics assumption, the feasibility of in-situ synthesized TiC particles are confirmed. As the content of in-situ synthesized TiC particles increases, the hardness and wear resistance of the coatings are improved. In addition, the replacement of Cr in the in-situ reaction is considered to be beneficial for the corrosion resistance of the coating and reduces the sensitivity of intergranular corrosion. Two types of distinct corrosion mechanisms have been proposed.