| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 615484 | Tribology International | 2011 | 9 Pages |
The aim of this paper is to use a modified slurry pot erosion tester to perform in-situ electrochemical measurements during solid particle impingement to investigate the effects of velocity, sand size and sand concentration on a passive metal (UNS S31603). Samples are subjected to a set of erosion–corrosion experiments. The electrochemical response of UNS S31603 to the test parameters is plotted and compared to develop an understanding of the erosion–corrosion process. The current trend with variation of test parameters has been explained by an erosion enhanced corrosion synergistic effect. The current transients associated with depassivation and repassivation during solid particle impingement are observed through electrochemical noise measurements. It was observed that the increase in velocity and sand concentration increased the current levels during erosion–corrosion. However, the increase in sand size had a more complex response. Single particle impact experiments conducted revealed that the peak corrosion current and the repassivation time increased with increase in velocity. A linear trend was seen between the peak current and the kinetic energy. A second-order exponential decay was fitted to the repassivation kinetics of the single particle impact. SEM has been used to develop a mechanistic understanding of erosion–corrosion. The surface scars reveal that the depth of the craters and the length of the lips increase with increase in velocity. Micro-cracks also appear on these lips, believed to be due to corrosive action attacking the roots of these lips.
Research Highlights►For the first time, a slurry pot erosion tester has been modified to perform in-situ electrochemical investigations and single particle impact experiments. ►Relationship between the effect of velocity, sand size, sand concentration on the corrosion current of stainless steel UNS S31603 has been investigated. ►Comparison has been made between single and multiple particle impact events in erosion-corrosion conditions. ►Mechanistic understanding investigated using SEM revealed cracking of the eroded surface believed to be due to electrochemical action of corrosion. ►Repassivation time and kinetics of single particle impact on UNS S31603 has been investigated.
