Study of Laser Cladding Iron-based Stainless Steel Powder Process on 45 Steel Surface

To resolve the issues of cracks and pores during the actual production process of the pump seal ring, as well as enhance its service life, laser cladding technique was employed to apply Fe-based stainless steel alloy coating on the surface of 45 steel matrix, thereby enhancing the surface performance of the sealing ring. The metallographic structure of the sample was examined using metallographic microscope, and by comparing metallographic micrographs, an analysis was conducted on the formation mechanism of the microstructure. Experimental samples underwent testing and analysis to evaluate their alloy coating properties, while exploring optimal combinations of technological parameters. The forming effect, elemental composition, hardness, wear resistance, and corrosion resistance were analyzed using various experimental equipment including coloring flaw detector, scanning electron microscope（SEM）, energy dispersive spectrometer（EDS）, microhardness tester, friction and wear testing machine, as well as salt spray corrosion testing equipment. The results show that laser power of 2000 W and scanning speed of 10 mm·s^-1are optimal cladding parameters for achieving good metallurgical bonding between the cladding layer and substrate. The microstructure of Fe-based stainless steel coating consists of planar crystal regions, cellular crystal regions, columnar crystal regions, and dendrite regions. The hardness distribution ranges from 60.1 to 62.7 HRC within the coating. The friction coefficient is approximately 0.5. Moreover, the corrosion resistance of the coating surpasses that of the substrate. Laser cladding with Fe-based stainless steel can significantly enhance the surface properties of 45 steel and prolong its service life.