Method of using intrinsically conductive polymers with inherent lubricating properties, and a composition having an intrinsically conductive polymer, for protecting metal surfaces from galling and corrosion

Abstract

A method for protecting a metal surface from galling and corrosion includes a step of providing a protective dry film on the metal surface. The film includes a solid lubricant and a conducting polymer, the conducting polymer having lubricant properties and being capable of binding the solid lubricant to the metal surface. Threaded metal joint surfaces coated with the film are capable of resisting galling under high pressure and high torque conditions, even after several fastening and unfastening operations or over a long period of time. Protection from corrosion is also provided by the film. The method and film are economical in that only a single layer of protective compound need be applied in order to provide metal surfaces with both lubrication and protection against corrosion, and problems such as removal or leakage, which are associated with protective compounds that use oils, are avoided. Additionally, the dry film is advantageous because it does not contain heavy metals that are harmful to the environment.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to corrosion-protection and lubrication of metal surfaces. In particular, the invention relates to a method of protecting a metal surface, such as the surface of threaded joints in oil tubings or casings, by applying a dry film including a binding intrinsically conductive polymer to the surface. The invention also relates to a composition for protecting a metal surface from galling and corrosion. [0003] 2. Description of the Related Art and Problem to be Solved A. Intrinsically Conductive Polymers and Corrosion Protection [0004] Intrinsically conductive polymers used as corrosion protection compounds are known in the art. One example of an intrinsically conductive polymer is polyaniline, which has been known to modify the electrochemical and corrosion behavior of stainless steels. For example, DeBerry has determined that stainless steel electrodes coated with thin films of polyaniline remain ...

AI Technical Summary

Benefits of technology

[0028] It is an object of the invention to provide protection from galling to metal surfaces, particularly threaded joint surfaces in oil tubing and casing subjected to high pressure, high friction, and high torque conditions.

[0029] It is another object of the invention to provide both galling-protection and corrosion-protection to metal surfaces through a simple application of a single compound.

[0035] Additives may be included in the dry film in order to enhance properties such as anti-corrosive properties, high stability of the polyaniline-molybdenum disulfide mixture, or improved adherence of the dry film. The properties of the dry film can also be modified by post-chemical treatment.

Problems solved by technology

However, the art does not disclose a method of using intrinsically conductive polymers with inherent lubricating properties, and a dry film having an intrinsically conductive polymer, for protecting metal surfaces from galling and corrosion.

However, no corrosion protection is provided.

Therefore, the patent does not disclose a dry lubricating process.

It also does not disclose the use of conductive polymer to lubricate or protect from corrosion.

The patent does not teach the use of an intrinsically conductive polymer layer as an anti-galling and anti-corrosive coating, alone or in combination with molybdenum disulfide.

However, the application does not teach a homogeneous layer of an intrinsically conductive, anti-corrosive polymer, which itself prevents galling and may be mixed with solid lubricant particles.

However, since anodization cannot be performed on iron (and iron-based alloys) or carbon steel surfaces, iron and carbon steel are not suitable metal substrates for the process of Runge-Marchese et al.

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