PRODUCTION OF JOINT MEMBER OF OIL WELL PIPE HAVING SUPERIOR CORROSION RESISTANCE AND SEIZING PREVENTIVENESS

• Main Authors: SAKAMOTO TOSHIHARU, YAMAMOTO KAZUO
• Format: Patent
• Language: English
• Published: 08.11.1988
• Subjects: BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; JOINTS OR FITTINGS FOR PIPES; LIGHTING; MEANS FOR THERMAL INSULATION IN GENERAL; MECHANICAL ENGINEERING; METALLURGY; PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; THERMAL INSULATION IN GENERAL; WEAPONS

PURPOSE:To produce a joint member of an oil well pipe having superior corro sion resistance and seizing preventiveness by forming an Ni layer of a specified thickness on the female screw part of the joint member by electroless plating and by forming a layer of projected and deposited steel shots each coated with a metallic Zn layer on the male screw part of each mother pipe. CONSTITUTION:Mother pipes 1 and a joint 3 are connected with male screws 2 cut at the ends of the pipes 1 and a female screw 4 cut around the joint 3. At this time, an Ni layer of >=5mu thickness is formed on the female screw 4 by electroless plating and layers of projected and deposited steel shots each coated with a metallic Zn layer 7 on an Fe-Zn alloy layer 6 are formed on the male screws 2 engaged with the female screw 4. Thus, a joint member of an oil well pipe having superior resistance to sulfide stress corrosion cracking and erosion corrosion and superior seizing preventiveness during fastening is obtd.