The temperatures inside the gas turbine reach up to 1000°C, alloys used for gas turbine components must be oxidation, and corrosion resistant, and stable in structure under high temperature circumstances. A Co-based alloy was cladded on the 1Cr18Ni9Ti stainless steel surface using a high power carbon dioxide laser. The microstructure evolution and hot corrosion properties of samples in 75%Na2SO4+25%NaCl saline were investigated. The results show that the microstructures of the cladded layer is fine, and the hot corrosion resistance of the cladded layer was significantly improved because of the formation of a protective oxide film of CoO and CoO•Cr2O3. Under high temperature corrosive atmosphere, the high content of Co promoted the formation of the protective oxide film. The refinement of dendritic structures and the formation of Co-based alloy oxides lower the penetration rate of the sulphur ions that induce the intergranular corrosion.

As is known to all, the technology is an effective way to improve the material surface performance. In this paper, Micro-arc spark deposition with stellite 6 alloy as the coating material on SCH13 steel substrates was carried out using high-energy micro-arc process. The microstructure, chemical composition, phase identification and hardness of the deposition layers were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Micro-hardness tester, respectively. Moreover, through high temperature oxidation, the property for the deposition layers of resistance to high temperature oxidation was analyzed systematically. The results show that the coatings were consisted of γ-Co solid solution and chromium carbides. The epitaxial growth coating with columnar grains was achieved by micro-arc spark deposition and the coating of stellite 6 alloy has a good metallurgical combination with the SCH13 steel substrate. After high temperature oxidation at 900°C, the surface film of the deposition layers were mainly consisted of chromium oxides, and the surface oxide film of SCH13 steel was Fe2O3and NiCr2O4, the property for the deposition layers of resistance to high temperature oxidation is obviously better than SCH13 steel substrate.