Abstract:
A threaded joint for an oil well pipe, characterized as having a screw part and/or a metal-metal contacting part with no screws which have, formed thereon, 1) a lubricating coating of an inorganic polymer having a skeleton of M (metal atom)-O (oxygen) and containing a solid lubricating agent dispersed and incorporated therein, 2) a phosphate coating and the above lubricating coating of an inorganic polymer, 3) a Cu plating layer, and the above lubricating coating of an inorganic polymer or a lubricating coating of a resin containing a solid lubricating agent dispersed and incorporated therein, or 4) the above lubricating coating of an inorganic polymer or the above lubricating coating of a resin, and a rust-inhibiting coating containing an alkali metal or alkaline earth metal salt of a carboxylic acid. The threaded joint for an oil well pipe can prevent the occurrence of galling in repeated make-up and break-out operations and at the same time secure high oil-tightness, with no use of a liquid lubricating agent such as a compounded grease.
Abstract:
A composition for lubricating-film formation which comprises a base and dissolved therein at least one basic oil selected among basic sulfonates, basic salicylates, and basic phenates. The composition is applied to the frictional surface of a box and/or pin constituting a screw joint to form a lubricating film. The composition can further contain one or more of particulate thermoplastic resins, other oils, and extreme-pressure additives. The mating parts preferably have a surface roughness of 5 to 40 mu m in terms of Rmax.
Abstract:
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 40ºC and, superimposed thereon, a lubricant layer in solid form at 40ºC or (2) a lubricant coating in solid or semisolid form at 40ºC comprising a mixture of lubricant oil in liquid form at 0 to 40ºC and wax in solid form at 40ºC (preferably a mixture obtained by liquefying the wax after mixing in advance and effecting mutual dissolution of the lubricant oil and wax).
Abstract:
When a metal strip material is cold rolled, roll cross rolling and roll parallel rolling are combined, and rolling is carried out by the roll parallel rolling system at at least the final stand (in the case of a tandem mill) or in at least the final pass (in the case of a single-stand mill such as reverse mill) to obtain a rolled metal strip free from torsion and having excellent luster. In some cases, preliminary cold rolling of a rolling reduction of at least 5 % is in advance applied to a metal strip material by the roll cross system, and then cold rolling by the combination of roll parallel rolling or roll cross rolling and roll parallel rolling is carried out.
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 - -40 micrometers.
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.
Abstract:
When a metal strip material is cold rolled, roll cross rolling and roll parallel rolling are combined, and rolling is carried out by the roll parallel rolling system at at least the final stand (in the case of a tandem mill) or in at least the final pass (in the case of a single-stand mill such as reverse mill) to obtain a rolled metal strip free from torsion and having excellent luster. In some cases, preliminary cold rolling of a rolling reduction of at least 5 % is in advance applied to a metal strip material by the roll cross system, and then cold rolling by the combination of roll parallel rolling or roll cross rolling and roll parallel rolling is carried out.