Effect of microstructure on tribocorrosion of FH36 low-temperature steels

The tribocorrosion performance of low-temperature steels is vital for use in hostile environments. This study aims to investigate the tribocorrosion behavior of FH36 low-temperature steel with two distinct microstructures of tempered martensite (TM) and tempered sorbite (TS), respectively. Also, the coefficient of friction, surface morphologies, electrochemical properties, and corrosion features of the two steels were investigated. The results showed that the TM and TS steel exhibited outstanding impact toughness values of 239 and 306 J at −60°C, respectively. The friction coefficient and the electrochemical impedance in the TM steel were lower than those of the TS steel, while the scratch was deeper and narrower in the TM steel. Both the microstructure and the electrochemical corrosion affect the wear resistance of the low-temperature steels during the tribocorrosion process. The friction can accelerate the adsorption of Cl− ions that enrich the pits near the scratches, and the pitting of the TM steel was severe.