Lubricating coating composition suitable for lubrication of a threaded joint
AssigneesSumitomo Metal Industries, Ltd., Vallourec Mannesmann Oil & Gas France
InventorsKunio Goto, Shigeo Nagasaku, Hideo Yamamoto
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Abstract
A lubricating coating composition in which at least one basic lubricant selected from a basic sulfonate, a basic salicylate, and a basic phenate is dissolved in a volatile solvent is applied to the frictional surface of a box and a pin constituting a threaded joint for oil well pipes. The composition may further contain one or more of a thermoplastic resin powder, another lubricant, and an extreme pressure agent. The surface roughness of the frictional surfaces preferably has an Rmax in the range of 5-40 micrometers.
Claims21
A lubricating coating composition comprising a volatile organic solvent, and at least one basic lubricant selected from a basic sulfonate, a basic salicylate, and a basic phenate which is at least partially dissolved in the solvent.
A lubricating coating composition consisting essentially of (A) 25-80 wt % of a volatile organic solvent, and (B) 75-20 wt % of at least one nonvolatile component, wherein 100 parts by weight of the nonvolatile component (B) consists essentially of 10-100 parts by weight of at least one basic lubricant selected from a basic sulfonate, a basic salicylate, and a basic phenate which is at least partially dissolved in the solvent (A), 0-30 parts by weight of a thermoplastic resin, 0-90 parts by weight of a lubricant other than the basic lubricant, and 0-15 parts by weight of an extreme pressure agent.
A threaded joint for metal pipes comprising a pin and a box capable of mating with each other, the pin having an externally threaded portion and an unthreaded metal contact portion, and the box having an internally threaded portion and an unthreaded metal contact portion, wherein at least one of the pin and the box has a lubricating coating formed on at least part of the threaded portion and/or unthreaded metal contact portion, the lubricating coating comprising at least 10 wt % of at least one basic lubricant selected from a basic sulfonate, a basic salicylate, and a basic phenate.
Dependencies are inferred from the claim text.