Improvement Corrosion Behaviour of Lean Duplex Stainless Steel 2101 alloy in Ringer solution by Plasma Nitriding for Biomedical applications

Abstract

“Plasma nitriding” is a surface hardening process that involves diffusion of the atoms of nitrogen onto the surface of metal under different plasma nitriding conditions. The new alloys used in the field of Biomedical applications are Lean Duplex Stainless Steel. The alloys of Lean DSS are corrosion resistant, lightweight, and have good mechanical properties such as fatigue strength, but in aggressive environments, they lack “wear resistance”. In a vacuum chamber of air (3 mbar), 400 V, and 30 mA, a lean duplex stainless steel (2101) alloy rod was plasma nitrided. The procedure of plasma nitriding was carried out at various times. The effect of plasma nitriding at different times (5, 10, 15, 20, 25) hrs on the chemical structure of LDX 2101 DSS alloy and the form of phases was investigated using OM, FESEM with EDS, XRD, and antibacterial test, tafel potential polarizaton and cyclic polarization for Orthopedic application. The results show that layers and phases S, Fe3N, and Fe2-3N were formed on the alloy’s surface, which would improve mechanical properties and corrosion resistance in Ringer solution at 37 °C.