In industrial production, lubricating greases are essential elements for ensuring the smooth operation of mechanical equipment. When these devices are exposed to high-temperature environments, the properties of lubricating greases often undergo a series of changes. So, how can we assess the quality changes of lubricating greases under high-temperature conditions?
Viscosity
As temperature rises, the viscosity of lubricating greases typically decreases. Viscosity is the ability of lubricants to resist flow. A decrease in viscosity means the thickness of the oil film becomes thinner, reducing lubrication effectiveness. This could lead to increased friction between equipment components and intensified wear.
Accelerated Oxidation
Under high-temperature conditions, the reaction between grease molecules and oxygen in the air intensifies, resulting in the formation of acidic substances, precipitates, and other compounds, which degrade its lubricating properties.
Increased Volatility
Some lubricating greases exhibit higher volatility at elevated temperatures, leading to a reduction in oil quantity and insufficient lubrication. Volatility can also carry away some additives, further weakening the grease’s ability to lubricate, prevent rust, and protect against corrosion.
Decreased Thermal Stability
In high-temperature environments, the thermal stability of lubricating greases faces significant challenges. Greases with poor thermal stability are prone to decomposition at high temperatures, generating tar, carbon deposits, and other residues. These deposits can clog the oil passages, disrupting the normal operation of the lubrication system.
To ensure proper performance in high-temperature environments, it's crucial to monitor the lubricant regularly and shorten the grease replacement cycle. Identifying and addressing these issues in a timely manner can effectively prevent mechanical failures that lead to production downtime, and the economic benefits of avoiding such failures far outweigh the cost of grease replacement.
