Nitretação por plasma a baixa temperatura em aços inoxidáveis com martensita de carbono e de nitrogênio

Abstract

The development of the industrial sector stimulate demand for materials that supports mechanical requests, resist corrosion with low cost. Among the available materials stainless steels have been a first choice especially when corrosion is relevant, however, in general performance is not always adequate when the demands are chemical and mechanical. The addition of nitrogen in solid solution has been used as a way to improve wear resistance without compromising corrosion resistance through the Solution Heat Treatment after Plasma Nitriding (SHTPN) process. This study aims to compare the effect of low temperature plasma nitriding on the carbon martensitic substrate of AISI 420 stainless steel and the martensitic nitrogen layer obtained by SHTPN on ferritic stainless steel AISI 409 at times 2, 4 and 6. hours at a temperature of 380 ° C. The resulting microstructure, nitrided layer thickness, top and profile microhardness analysis and phase analysis by XRD were evaluated. The results indicated the formation of an expanded nitrogen martensite layer on the surface of both stainless steels and it was found that the layer thickness and top hardness were higher for AISI 409 stainless steel than AISI 420 stainless steel for all nitriding time conditions.