Spreadability and Scuffing Resistance of Marine Cylinder Oil under High Temperature

Abstract

 High base number cylinder oils provided inferior anti-scuffing performance in high temperature, low feed-rate conditions, as well as inferior high temperature spreadability. When cylinder oil is degraded under high-temperature thin-film conditions, carboxylic acid is formed as a decomposition product of the oil. This carboxylic acid is neutralized by calcium carbonate in the oil, forming calcium carboxylate. The calcium carboxylate complexes associate to form high molecular weight products, leading to increased viscosity and reduced spreadability, which reduces the oil’s ability to prevent scuffing at high temperature. Cylinder oils that have high oxidation stability not in bulk fluid but rather in thin film conditions will exhibit a smaller viscosity increase, a high spreadability and greater anti-scuffing performance.