Corrosion behaviour of HVOF-sprayed Fe-based Amorphous Coatings
±, Lin Liu*
State Key Laboratory of Material Processing and Die & Mould Technology, Huazhong University of Science and Technology, 430074 Wuhan, China
Email: czhang@hust.edu.cn; lliu2000@mail.hust.edu.cn;
Abstract:
Thermally sprayed amorphous coatings have attracted great attention due to their outstanding corrosion resistance, showing a wide range of industrial applications. In this talk, I will report our recent process on the electrochemical study of HVOF-sprayed amorphous coating under a high hydrostatic pressure (80 atm). The results indicate that the general corrosion rate of the coating increased at 80 atm with respect to that at 1 atm, yet the localized corrosion resistance did not change much. TEM observations reveal that the passive film formed at 80 atm is much thicker than that formed at 1 atm due to a faster dissolution rate of metals and diffusion rate of ions under high hydrostatic pressure, which have a compensation for the decrease of stability and compactness of the passive film, such that the good localized corrosion resistance of the amorphous coating is reserved at high hydrostatic pressure. Furthermore, a new sealing treatment was developed for the amorphous coatings, which recoveries the outstanding corrosion resistance of amorphous coatings under high-pressure environments.