Effect of different acidic media on the corrosion behaviour of hardmetals with Ni-based binders

Abstract

Highly corrosive agents, such as saltwater, hydrogen sulphide, hydrofluoric or hydrochloric acids, are frequently found in oil and gas exploration. The high costs associated with the premature replacement of equipment damaged by corrosion and the consequent production losses justify the search for more resistant materials. In this work, the corrosion behaviour of cemented carbides with different Ni-based binders in highly corrosive environments (HCl and HF) was studied by electrochemical techniques (EIS, OCP and polarization curves). HF was slightly more aggressive than HCl and far more corrosive than near neutral NaCl solution. The hardmetals with Ni-based binders presented a corrosion resistance superior to WC-Co in all environments.