High Temperature Effects on Grease

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High Temperature Effects on Grease

High-temperature effects. High temperatures harm greases more than they harm oils. Grease, by its nature, cannot dissipate heat by convection like a circulating oil. Consequently, without the ability to transfer away heat, excessive temperatures result in accelerated oxidation or even carbonization where grease hardens or forms a crust. Effective grease lubrication depends on the grease's consistency. High temperatures induce softening and bleeding, causing grease to flow away from needed areas. The mineral oil in grease can flash, burn, or evaporate at temperatures above 177 EC (350F). High temperatures, above 73-79C (165-175F), can dehydrate certain greases such as calcium soap grease and cause structural breakdown. The higher evaporation and dehydration rates at elevated temperatures require more frequent grease replacement.