Abstract
The addition of 500ppm potassium dichromate (PDC, K2Cr2O7) to a silica sand-water slurry decreased the amount of slurry erosion damage of commercially pure iron as well as of aluminium to the value smaller than that of pure erosion. Further, the salt (NaCl) dissolved 3% in the slurry water enhanced the erosion-inhibiting effect of PDC. Thus, it was concluded that PDC adsorbed on the surface of the metals and affected directly the erosion process. It was also found that the erosion-controlling mechanism varried with the particles impact angle: at an impact angle of 30°, it was the reduction of friction coefficient of the metal surface. At 70°, it was the tension applied to the metal surface through the adsorbed ions, which inhibited the plastic deformation of the surface.
