High temperature gas nitriding (HTGN) has a large impact on enhancing the corrosion behavior of martensitic stainless steels. The variation in nitriding time was investigated with respect to microstructure, surface hardness (nanoindentation), alloying element content near the surface (GDOS) and pitting corrosion resistance. The study shows that quenching in 10 bar nitrogen enhances the nitrogen content near the surface. Samples heat treated without any nitrogen addition though quenched in nitrogen, exibits an improvement of corrosion resistance. Furthermore the hardness increases too, compared to a non heat treated sample. Specimens quenched in helium also display an enhancement of the pitting corrosion resistance, however the hardness increases lesser. Simulations are supporting this assertions.