Wear and corrosion study of plasma nitriding F53 super duplex stainless steel

Abstract

Super duplex stainless steels (SDSS) have high corrosion resistance because of their high contents of chromium, nickel, molybdenum and nitrogen but low wear resistance. To improve the wear resistance of these steels without affecting their corrosion resistance, samples of SDSS were treated by plasma ion nitriding at temperatures ranging from 350°C to 570°C for two hours. This thermochemical treatment resulted in the formation of different types of nitrides that affected the microhardness, the microwear behaviour and the corrosion resistance of the metal surface. The microwear resistance decreased at 400°C because different nitrides formed on the surface, thereby increasing the hardness and volume wear resistance of the steel. The test results showed that the alloys that were nitrided at 400°C and 450°C exhibited the highest corrosion resistance to a solution medium containing chloride ions.