2011 Volume 52 Issue 3 Pages 474-480
High chromium Fe-Cr-Mo-P-C amorphous coating films containing up to about 35 at% Cr having high hardness and high corrosion resistance have been produced by a newly developed thermal spraying technique. In order to control the temperatures of the powder particles in the flame spray and the substrate, a cylindrical nozzle, with external cooling nitrogen gas, was mounted to the front end of the thermal spraying gun. Fe70Cr10P13C7 and Fe38Cr35Mo7P13C7 films with various external cooling gas velocities between 20 m/s and 40 m/s exhibited entire amorphous structure without oxides and/or unmelted powder particles. High corrosion-resistance of the Fe38Cr35Mo7P13C7 amorphous coating film was observed in immersion tests using 35% hydrochloric acid.