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AssigneesNippon Steel & Sumitomo Metal Corporation, Vallourec Mannesmann Oil & Gas France
InventorsKunio Goto, Takayuki Kamimura, Masaru Takahashi, Keishi Matsumoto, Michihiko Iwamoto, Ryuichi Imai, Stephanie Rai
Estimating the term…
In a threaded joint for pipes constituted by a pin and a box, each having a contact surface comprising a threaded portion and an unthreaded metal contact portion, the contact surface of the pin has a solid corrosion protective, preferably transparent coating based on a UV-curable resin and the contact surface of the box has a solid lubricating coating having plastic or viscoplastic rheological behavior which is preferably formed by the hot melt technique from a composition comprising a thermoplastic polymer, a wax, a metal soap, a corrosion inhibitor, a water-insoluble liquid resin, and a solid lubricant.
A threaded joint for pipes constituted by a pin and a box, each having a contact surface comprising a threaded portion and an unthreaded metal contact portion, characterized in that the contact surface of the box has a solid lubricating coating having plastic or viscoplastic rheological behavior as an uppermost layer, and the contact surface of the pin has a solid corrosion protective coating based on a UV-curable resin as an uppermost layer.
A surface treatment method for a threaded joint for pipes constituted by a pin and a box, each having a contact surface comprising a threaded portion and an unthreaded metal contact portion, characterized by forming a solid lubricating coating having plastic or viscoplastic rheological properties on the contact surface of the box, and forming a solid corrosion protective coating on the contact surface of the pin by application of a composition based on a UV-curable resin followed by irradiation with UV light.
Dependencies are inferred from the claim text.