Abrasion–corrosion: New insights from force measurements

Abstract

Aiming at the study of synergy between the abrasion and corrosion a new instrument, enabling the measurement of forces acting on the contact, has been designed. The test rig consists of a fixed-ball micro-abrasion tester, where the specimen is supported by a three-axis load cell, and an electrochemical cell. A very flexible protective membrane has been designed to isolate the load cell, located outside the electrochemical cell, from the sample inside the cell. A mixture of a corrosive fluid and abrasive particles is continuously fed to the contact. Simultaneous micro-abrasion/corrosion tests have been performed in austenitic and ferritic stainless steels. In addition, independent micro-abrasion and corrosion tests were also carried out to evaluate the capacity of the rig to account for the synergy between micro-abrasion and corrosion. For all three tests (micro-abrasion, corrosion and combined micro-abrasion/corrosion) the rig was efficient to respond to variation in material properties and showed excellent repeatability. For the austenitic steels, changes in loading conditions in combined micro-abrasion and corrosion tests induced significant variations on polarization curves. The unique capability of monitoring the forces acting on the contact of abrasion–corrosion processes could pave the way for new insights into the study of abrasion–corrosion, in particular the dissipation of energy at the interface quantified via the friction coefficient.