Development of a Corrosion and Wear Resistant Material

For fluid machinery used in seawater, the overlaying technique is an effective means for the resistance to corrosion, erosion and abrasive wear in terms of cost, performance and repair. Therefore, we had attempted to combine the manufacturing technique of anti-wear resistant Co based KV powder and Crevelloy alloy with excellent crevice corrosion resistance. As the results, the overlayer containing 15%massVC, 35%massCr, and 15%massMo shows high hardness and excellent anti-corrosion property. High hardness of overlayer is mainly caused by matrix phase with lamellar structure consisting Ni-Cr-Mo-Fe alloy phase and carbide phase. Corrosion property was evaluated by cyclic potentiodynamic anodic polarization curve measurement in 3.0%NaCl aq. at 25°C, pitting potential measurement in 3.5%NaCl aq. at 80°C and 6-months immersion test in seawater. Erosion property was evaluated by slurry jet test and vibratory cavitation erosion test. From the evaluation results, developed material VCRMO is recommended as overlaied alloy for seawater applications.