1968 年 32 巻 1 号 p. 7-10
Recently cemented carbides have been used in the field of chemical industry as a corrosion resistance material.
In this report the chemical resistance of cobalt-base cemented carbides against hydrochloric acid, sulfuric acid, nitric acid and citric acid are examined for 50 hr and 100 hr at room temperature and at 95°C, respectively. The results obtained are summarized as follows: The weight loss data indicate that the corrosion of cemented carbides is due to the disolution of cobalt as binder metal and the resistance against acids increases with decreasing cobalt content. The passive film formed on the surface of cemented carbides attacked by nitric acid suppreses the chemical reaction. The corrosion resistance of cobalt-base cemented carbides was comparable to that of Stellite, stainless steel and Hastelloy.