The influence of gradient SiNx IBAD coating on corrosion resistance of alloy steels in oxidizing and sulphidizing-oxidizing atmosphere at high temperature

摘要

SiNx IBAD coatings were applied to low-alloy steel (0.4 mu m thick) and to high-alloy steels AISI 310 and 321 (0.8 mu m) at 90 keV energy nitrogen ions. The samples were subjected to a high temperature corrosion test for 2000 h; low-alloy steel in air and high-alloy steels in sulphidizing-oxidizing atmosphere at temperatures 500-700 degrees C. In both gaseous environments the application of SiNx increased the corrosion resistance of the tested steels. The protective function of SiNx coating consists of its barrier effect and in some cases it supports the formation of a compact protective SiO2 layer. (C) 1998 Elsevier Science S.A. [References: 4]