Effects of benzotriazole and imidazoline on the tribocorrosion behaviors of a WC-based material in saline silica slurries

Abstract

To improve the performance of impregnated diamond bit in saline drilling fluid, the effects of benzotriazole and imidazoline on the abrasion–corrosion behaviors of a hot-pressed WC-based material and its binder material in saline silica slurries were investigated with a modified abrasion test rig. The morphology of worn surface and corrosion products after tribocorrosion test were analyzed by scanning electron microscopy and Raman spectroscopy, respectively. The results indicated that benzotriazole was a better corrosion inhibitor for the two hot-pressed materials than imidazoline. In abrasion-corrosion tests, the addition of benzotriazole into saline slurry reduced the total weight loss considerably and produced a negative abrasion–corrosion synergy, while imidazoline had hardly noticeable effects, especially to the binder material. The negative synergy could be related to the change in contact condition between abrasive particles and worn surface, owing to the decrease in the adsorption of benzotriazole on the worn surface as a result of cathodic protection. By lowering the corrosion rate of the binder around WC particles and thus lessening the undermining of WC particles, benzotriazole significantly improved the anti-tribocorrosion performance of the WC-based material.