Heat treatment process for welding area of sulfur-resistant drill rod and drill rod prepared by heat treatment process

Abstract

The invention discloses a heat treatment process method for a welding area of a sulfur-resistant drill rod. The welding area of the drill rod is formed by inertia friction welding of a 95SS or 105SS pipe body and a 110SS sulfur-resistant drill rod joint. The heat treatment of the welding area of the drill rod comprises the steps of primary quenching, secondary quenching and tempering. During the primary quenching, the center of a quenching heating ring is aligned with the position, 3-8 mm away from the pipe body, of a welding seam, and the quenching heating temperature is 840-880 DEG C. During the secondary quenching, the center of the quenching heating coil is aligned with the position, 3-8 mm away from the pipe body, of the welding seam, and the quenching heating temperature is 790-820 DEG C. During tempering, the center of a tempering heating coil is aligned with the position, 3-8 mm away from the joint, of the welding seam, and the tempering heating temperature is 680-720 DEG C. According to the heat treatment process, the hardness value of the welding area of the 95SS or 105SS sulfur-resistant drill rod is uniform, the tensile strength, elongation and impact toughness of the welding area are better, the hydrogen sulfide stress corrosion resistance of the welding area is stable and reliable, and the qualified rate of batch production is high.

Description

Technical field [0001] The present invention belongs to the technical field of petroleum drill rod, and more particularly to a heat treatment process and a drill pipe prepared therefrom therefrom. Background technique [0002] With the rapid growth of oil and gas resources, more and more acid oil and gas fields, hydrogen sulfide in these acidic oil gantry often lead to cracking of sulfide stress in the drill pipe, suddenly brittle break, causing huge economic losses. To this end, it is increasingly high and higher to corrosion resistance of hydrogen sulfide stress. [0003] 95ss or 105SS anti-sulfur rod pipe body and joint is most effective, and most reliable connection method is inertial friction welding, while the heat treatment process of welding is directly determined by mechanical properties and metallographic tissue of drill pipe welding, and inappropriate heat treatment processes can result in The regional hardness difference between the drill rod weld line is large, while...

AI Technical Summary

Problems solved by technology

In the prior art, when heat treating the welding zone of 95SS or 105SS sulfur-resistant drill pipe, both the quenching heating coil and the tempering heating coil are aimed at the weld seam line. In order to reduce the peak hardness of the weld seam line, the tempering temperature is usually increased, so that The problem is that the strength and hardness of the heat-affected zone on the side of the pipe body is low. If the tempering temperature is lowered, the hardness of the weld line and the joint side will be higher. The hardness of the entire weld line area is quite different, and the hardness of some areas even reaches above 32HRC. , the hydrogen sulfide stress corrosion resistance of the welding zone is difficult to meet the requirements

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