| 摘要 |
<p>A screw joint for steel pipe, comprising pin (1) provided with a contact surface, which has screw portion (3) or (4) and nonthreaded metal contact portion (8), and box (2), wherein a lubricant coating exhibiting self-repair capability through liquid lubrication and having its surface tackiness restricted is formed on the contact surface of at least one of the pin and box so as to attain an enhancement of seizure resistance. This lubricant coating is either (1) a lubricant coating comprising a lubricant layer in liquid form at 0 to 40 degree C and, superimposed thereon, a lubricant layer in solid form at 40 degree C or (2) a lubricant coating in solid or semisolid form at 40 degree C comprising a mixture of lubricant oil in liquid form at 0 to 40 degree C and wax in solid form at 40 degree C (preferably a mixture obtained by liquefying the wax after mixing in advance and effecting mutual dissolution of the lubricant oil and wax).</p> |
