Geological drill pipe and its manufacturing method

Abstract

The invention discloses a geological drill rod and a manufacturing method thereof. The geological drill rod comprises the following components in percentage by weight: 0.23-0.28% of C, 1.05-1.2% of Mn, 0.17-0.35% of Si, less than or equal to 0.015% of P, less than or equal to 0.01% of S, 0.15-0.25% of Mo, 0.8-1% of Cr and the balance Fe and inevitable impurities. The manufacturing method for the geological drill rod comprises the following steps of: smelting the chemical components into molten steel through an electric furnace, and continuously casting the molten steel into drill rod tube blank; adopting a press to carry out thickening treatment of once heating and once forming on two ends of the drill rod tube blank, thereby obtaining a drill rod tube body; processing a drill rod male joint and a drill rod female joint through a numerical-control machine tool; welding the drill rod male joint and the drill rod female joint to thickened parts at the two ends of the drill rod tube body in a friction welding mode via a welding machine; and adopting a heating furnace to carry out tempering thermal treatment on a welding seam according to a process route of annealing, quenching and tempering, and naturally cooling to the room temperature, thereby obtaining the finally geological drill rod. The geological drill rod disclosed by the invention is good in tensile property, torsion resistance and impact resistance, so that drill tool failure accidents such as drill rod joint expanding and buckling, welding seam breakage and tube body puncture leakage during drilling operation are effectively reduced, and the service life of the drill rod is prolonged.

Description

technical field [0001] The invention relates to a drill pipe, in particular to a geological drill pipe used for geological core drilling such as geological exploration and coal mining and a manufacturing method thereof. Background technique [0002] The drill pipe plays the role of transmitting power and conveying mud in the drill string system. During the working process, it will be subjected to extremely harsh alternating torque and vibration. Therefore, it must have good torsion resistance and impact resistance to ensure the normal use of the drill pipe. . [0003] At present, the geological drill pipes used in China are mostly welded with threaded joints and flat-end rods. The torsion resistance and impact resistance of this kind of drill pipe are poor. When encountering sudden changes in hardness rocks, geological subsidence, etc., which cause instantaneous force overload on the drill pipe, joint buckles, weld fractures, etc. often occur. Drilling tool failure acciden...

AI Technical Summary

Problems solved by technology

The torsion resistance and impact resistance of this kind of drill pipe are poor. When encountering sudden changes in hardness rocks and geological subsidence, which cause instantaneous force overload on the drill pipe, joint buckles, weld fractures, etc. often occur. Drilling tool failure accidents such as pipe body puncture

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