Assessing the corrosion-wear behaviours of Hastelloy C276 alloy in seawater

Abstract

A systematic investigation has been carried out in the present work to study the electrochemical and corrosion-wear behaviours of Hastelloy C276 alloy sliding against Al 2 O 3 pin in artificial seawater, using a pin-on-disc tribometer integrated with a potentiostat for electrochemical control. It can be observed that the cathodic shift of open circuit potential and three order of magnitude increase of current density formed due to sliding. The total corrosion-wear loss increases with increasing applied potential. Interestingly, the total material loss at the applied potential of 0.5 and 0.9 V is more than two times of that of pure mechanical wear, confirming the synergy between wear and corrosion. And, the contributions of wear-induced corrosion (ΔK c ) and corrosion-induced wear (ΔK w ) are dominant, especially at higher applied potentials.

Tribo‐electrochemical study of stainless steel surfaces during chemical–mechanical polishing

“…Interestingly, the sharp peaks in potential at 8761 and 9081 s coincide with an OCP surge and a decrease in COF, as marked by the interrupted vertical lines. These correlations suggest the discontinuous formation of third body particles by mechanical wear, a concept initially developed by Godet and adopted by other authors . Wear particles are detached from the first body (AISI 304 steel disc) leading to a sharp increase in the OCP due to oxidation of the fresh active steel surface exposed to the corrosive environment.…”

“…However, it should be noted that the OCP recovering time for the surface rubbed with the Electrolyte 1 is longer, indicating a slower regeneration of the passive films when compared to the surface rubbed with Electrolyte 2 . It has been reported that this cyclic depassivation–repassivation mechanism leads to wear accelerated corrosion . It can be seen that throughout the entire sliding period, the OCP fluctuates strongly in case of the surface rubbed with Electrolyte 1.…”

Effect of electrochemical potential on the corrosive wear behavior of 5052 aluminum alloy in 0.5 M NaCl solution

“…It is easy to observe that OCP stabilize at the value of about −0.7 V in initial 5‐minute stabilization. Once rubbing, the OCP abruptly shifts to the cathodic direction, which is usually explained by the destruction of the surface passive state . The increasing load would enlarge the degree of cathodic shift of OCP.…”

“…When rubbing is terminated after 25‐minute sliding, the OCP increases abruptly and returns the original OCP value (−0.7 V). This can be explained by the repassivation of the wear track without rubbing …”

“…The passive film can be easily removed by abrasion, thus exposing the underlying reactive material to more severe corrosion. During the tribocorrosion process, accelerated wear was always observed for various metal materials by combining mechanical, chemical, and electrochemical factors . The tribocorrosion behavior of several aluminum alloys has been studied before.…”