Laser heat treatment method of large taper screw thread of drill collar and circular bead surface

Abstract

The invention belongs to the technical field of drill collar surface treatment and particularly relates to a laser heat treatment method of a large-taper screw thread of a drill collar and a circularbead surface, solving the problem that no favorable processing methods are available for the large taper screw thread of the drill collar and the circular bead surface so as to cause failure. The irradiating step is as follows: a laser beam irradiates one lateral surface of a taper thread form an angle that is perpendicular to the surface of the screw thread and moves along an intermediate diameter generatrix direction, and the drill collar rotates simultaneously; when the circular bead surface is treated, the laser beam turns to move along the radial direction of the drill collar to irradiateand the drill collar rotates simultaneously; and once the drill collar rotates a circle, the laser beam lifts a width of a spot. The invention has the advantages that no deformation of a series of the large taper screw threads of the drill collar and the circular bead surface thereof is caused in a normal test, improving the rigidity and the wear resistance; the surface is bright and clean without cracks, thereby reducing bonding failure; and the drill collar is convenient to disassemble smoothly in the drilling process, thereby benefiting the well drilling production of oil fields.

Description

technical field [0001] The invention belongs to the technical field of drill collar surface treatment, and in particular relates to a laser heat treatment method for a drill collar with a large taper thread and a shoulder surface. Background technique [0002] At present, for slender rod parts such as drill collars, the aspect ratio L / D=50~100, the main process usually used is: drilling deep holes (L≈10 meters), turning the outer circle, quenching and tempering treatment, flaw detection, Internal and external taper threads of vehicles, thread phosphating and close distance inspection, surface painting, etc. According to the requirements of SY / T5144, only the quenching and tempering treatment is carried out on the rods, and no special heat treatment is carried out. Although the steel used for drill collars is a special alloy structural steel required by SY / T5144, which needs to be smelted and rolled separately, its service conditions are harsh and it is subject to large torq...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides a laser heat treatment method for large-taper threads and shoulder surfaces of drill collars in order to solve the problem that there is no good processing method for the large-taper threads and shoulder surfaces of the existing drill collars, resulting in failure.

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