Surface Chemistry of Chlorinated Hydrocarbon Lubricant Additives–-Part I: Extreme-Pressure Tribology

Chlorinated hydrocarbons are commonly added to a base lubricating fluid when it is used for extreme-pressure (EP) lubrication of ferrous metals. It is demonstrated here that the interfacial temperature in the EP regime varies linearly with the applied load in a pin and v-block testing apparatus and that temperatures in excess of ˜ 1000 K can be attained. Thermally decomposing chlorinated hydrocarbon vapors on iron heated to these temperatures (1) shows that a film consisting of an iron chloride which incorporates small carbon particles (˜50Å) is formed. In this paper, tribological measurements at extreme pressures and the corresponding analyses of the rubbing surfaces and wear particles also indicate that this film, formed from the chlorinated lubricant reacting with these surfaces, is the critical antiseizure material at less severe EP loads and interfacial temperatures less than ˜1000 K.

KEY WORDS

• Additive Deposition,
• Auger Electron Spectroscopy (AES),
• Barrier Films,
• Extreme-Pressure Additives,
• Ferrous Alloys,
• Iron,
• Metalworking,
• Materials Machining,
• Thermal Degradation,
• Thermal Effects,
• X-ray Photoelectron Spectroscopy (XPS)