How do sulfur compounds in gear oils prevent metal surfaces from seizing?

In the context of gear lubrication, sulfur compounds serve as essential additives to manage extreme pressure conditions. When high loads are applied to gears, these compounds react to form a protective, resistant film on the metal surfaces. This film acts as a barrier that prevents direct metal-to-metal contact, which is the primary cause of surface seizing and wear.1

While sulfurized olefins and various polysulfides are commonly employed in these industrial lubrication applications, their effectiveness relies on this ability to create a sacrificial layer that maintains separation between moving parts under intense stress.21