Synergistic effect between corrosion and wear has been widely recognized in many tribo-corrosion systems. In most wet application conditions, dissolved oxygen (DO) is a controlling factor to the dynamics of corrosion process and is therefore expected to have significant impact on the tribo-corrosion performance of materials. In this study, the effect of DO (0 - 24 ppm) on erosion-corrosion behaviour of En30B low alloy steel has been investigated using a slurry pot erosion-corrosion test apparatus in a slurry containing 35wt% silica sand and 3.5% NaCl solution at 30°C and 45°C. The synergistic effect and its contributing components, i.e., erosion-enhanced corrosion and corrosion-enhanced erosion, have been measured/analysed. The total erosion-corrosion loss and synergy of the En30B steel increases with DO in the slurry, initially rapidly at DO levels below ~5 ppm and then less rapidly at the higher DO levels. The synergistic effect is mainly due to corrosion-enhanced erosion with negligible contributions from erosion-enhanced corrosion. Temperature has a significant effect on the total erosion-corrosion loss. Total erosion-corrosion was 34% higher at 45°C (in still air) than at 30°C. Mechanisms for the observed phenomena have been discussed based on the concept of corrosion-accelerated micro-crack propagation.
- dissolved oxygen
- corrosion process