Effect of Surface Properties Modification on Slurry Erosion-Corrosion Resistance of AISI 5117 Steel

The erosion-corrosion (E-C) wear behaviors of electroless nickel phosphorus (Ni-P) coating, carburizing and untreated low alloy steel AISI 5117 in water-sand slurry and saline-sand slurry were investigated using whirling-arm tester. The E-C wear mass loss was measured to evaluate the effect of mediums and surface modifications. The microstructure of carburizing and Ni-P coating was analyzed using an optical and scanning electron microscope (SEM) and X-ray diffraction (XRD) technique. Results showed that Ni-P coating and carburizing are effective in increasing wear resistance of low alloy steel. However, the Ni-P coating is more effective in increasing the E-C resistance. Also, the results showed that Ni-P coating, carburizing and untreated carbon steel behaved as ductile materials under erosion and E-C tests, and the maximum mass loss occurred at an impact angle of 45 deg. The synergism ratio was the lowest for the Ni-P coating, indicating that Ni-P coating improved an anti-E-C wear resistance.