ON THE FRICTION AND ANTI-GALLING PROPERTIES OF ENGINEERING COATINGS AND SURFACE TREATMENTS

摘要

Long-lasting protective coatings and surface treatments against wear and corrosion are critical to the proper actuation of many oilfield equipment over their life cycle. Traditional coatings (e.g., electroless nickel, sprayed carbides) and surface treatments (e.g., nitriding, boronizing) in use in the oilfields on stainless steels and nickel alloys lack engineering characterizations; similarly, newer coatings (e.g., electroplated composites, diamond-like carbons (DLCs) require benchmarking against their traditional references. In response to practical engineering needs, a study has been launched with 17 coatings and surface treatments to characterize frictional behaviors under dry and high-contact pressure conditions. This study shows that (1) self-lubricated coatings outperform other coatings and surface treatments, (2) soft coatings wear out and loose lubricity over time, and (3) hard coatings incorporating solid lubricants remain promising to balance low-friction, abrasive wear, and long-term environmental resistance.