抄録
In order to evaluate corrosion characteristics of cemented carbides in wide pH range of aqueous solutions from strong acidity to strong alkalinity, the effects of carbon content in the alloy and Cr3C2 addition on corrosion characteristics of WC-10%Co alloys were investigated by mainly measuring potentiodynamic polarization curves of them. The results obtained were as follows; (1) In the case of aqueous solutions of strong acidity and weak acidity close to neutrality, corrosion speed in pseudo-passive region decreased with the decrease of carbon content in the alloy. (2) The effect of corrosion repression by Cr3C2 addition was small in the strong acid solution, but so big in the weak acid one. (3) The corrosion in the strong and weak acid solutions was mainly due to the dissolution of the cobalt phase. (4) In the case of strong alkali solution, the alloys showed almost same polarization curves with no relation to carbon content in the alloy and Cr3C2 addition because the corrosion was due to the dissolution of WC phase.
