Effect of Annealing Treatment on the Microstructure and Properties of 316L Stainless Steel Coating Deposited by Low Pressure Plasma Spray

The lamellar and equiaxed micorstructure 316L stainless steel coatings were deposited by low pressure plasma spray under the certain spray process parameters. The results obtained by optical microscopy showed that the lamellar coating was constituted by the flattened particles, and the micorstructure of equiaxed coating similar to the annealed 316L stainless steel bulk with particle interfaces almost disappearing. Annealing treatment was applied to the coating to investigate lamellar – equiaxed microstructural transition and grain growth, by using different annealing temperature and time. The microhardness and the corrosion resistance of the as-sprayed coating and the annealed coating were also compared in the article.