Tribological behavior of 316H stainless steel in NaNO3-KNO3 molten salt at elevated temperature

The corrosion behaviors of stainless steels in various high-temperature molten salt have been extensively investigated. However, the tribological behavior of the alloys acting as moving parts in the molten salt is rarely reported. In this work, 316H stainless steel was selected to comparatively study its high-temperature tribo-corrosion performance in molten solar salt (60% NaNO3+40% KNO3, wt.). Under the drying sliding condition, the wear rate increases at 500 °C though the friction coefficient decreases compared to that at room temperature. In contrast, compared to the 500 °C dry sliding condition, the wear resistance of 316H at 500 °C in molten nitrate salt is remarkably improved owing to the lubrication effect of the molten salt and the enhanced oxidation tendency on the worn surface.