INFLUENCE OF Cr ADDTION ON CORROSION RESISTANCE OF WC-BASED CEMENTED CARBIDE

The mechanical properties and corrosion resistance of the WC-based alloy containing different quantities of Cr in the binder were studied.The bending strength of the alloy decreased but hardness increased with increasing Cr addition.The corrosion resistance was greatly improved with increasing Cr addition.In the erosion-corrosion experiments,the maximum corrosion rates of various alloys with different components were all observed at the impact angle of 60°.When the rotational speed of the rotating disc reached 1000rpm,the corrosion rate of the alloy increased suddenly,and the effect of mechanical synergism occurred obviously. Through the SEM observation of the alloy section and surfaces corroded,it was found that the passive film of WC-based cemented carbide with Cr addition was more integrated and it had stronger binding force with the substrates than that of the alloy without Cr addition.