Influence of the spraying processes on the properties of 316L stainless steel coatings

The 316L stainless steel coatings produced by different thermal spraying processes are usually used to improve the corrosion behaviour of steel surfaces. In this study the coatings of 316L stainless steel were produced using atmospheric plasma spraying, shrouded plasma spraying and high velocity oxy-fuel spraying (HVOF). The influence of the thermal spraying processes and spray parameters on the properties of the coatings was investigated. The coatings were studied in terms of their microstructure, oxidation and corrosion behaviour. The corrosion behaviour of the coatings was evaluated using electrochemical polarisation measurements in 0.1 N H2SO4 and 0.1 N C6H8O7·H2O acid solutions. The experimental results revealed that dense coatings could be produced using all the three processes. The coatings with low oxidation could be produced by HVOF. The HVOF coatings were harder than other coatings. The HVOF coating showed also the best corrosion behaviour.