A study was carried out on the corrosion resistance of the JP- 5000 coatings of Superalloy 625, WC-12%Co, WC-17%Co, WC-10%Co-4%Cr and Cr3C2-25NiCr materials and comparisons made with chrome plating. The coating corrosion resistance was evaluated using the standard salt fog test (ASTM B117) and also by submersion tests in 10% FeCl3 solution (ASTM G48), in 10% HNO3 and in 0.1M H2SO4 + 0.2M HCl solutions. The coating corrosion mechanisms in relationship with the coating microstructure and phase constitutions are discussed. The test results show that the HP/HVOF coating corrosion resistance can be significantly improved through spray parameters and coating structure optimization. All coatings tested herein having optimum microstructure and phase constitutions have shown improved corrosion resistances in comparison with chrome plating.