Hydrogen sulfide corrosion-resistant steel for petroleum drill rod and manufacturing method for hydrogen sulfide corrosion-resistant steel

Abstract

The invention discloses hydrogen sulfide corrosion-resistant steel for a petroleum drill rod and a manufacturing method for the hydrogen sulfide corrosion-resistant steel. The steel for a drill rod pipe body comprises the following chemical components in percentage by weight: 0.20 to 0.35 percent of C, 0.1 to 0.5 percent of Si, 0.3 to 1.5 percent of Mn, 0.5 to 1.5 percent of Cr, 1.0 to 2.5 percent of Mo, 0 to 0.25 percent of V, 0 to 0.05 percent of Ti, 0.01 to 0.05 percent of Nb, 0.008 to 0.02 percent of Ca, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, less than or equal to 30ppm of O, less than or equal to 60ppm of N, 0.01 to 0.05 percent of Al and the balance of Fe and inevitable impurities. The method for manufacturing the drill rod pipe body comprises the following steps of: smelting by using an electric furnace; performing LF+VD dual vacuum treatment after the smelting; performing LF refining to ensure that [N] is less than or equal to 30ppm, and [O] is less than or equal to 10ppm; standing for 5 to 15 minutes after VD vacuum treatment; treating the Ca in a Si-Ca silk feeding mode; continuously casting, and controlling the continuous casting blank pulling speed to be between 1.8 and 2.5m/min; hot rolling the materials to form a seamless steel pipe, thickening the two ends of the seamless steel pipe, heating at the temperature of between 850 and 950 DEG C, keeping the temperature for 0.5 to 1 hour, and quenching; and keeping the temperature of between 680 and 730 DEG C for 1 to 3 hours, tempering, and thus obtaining the drill rod pipe body, wherein the yield strength of the pipe body is more than 120ksi.

Description

technical field [0001] The invention relates to a hydrogen sulfide corrosion-resistant petroleum drill pipe steel, in particular to a hydrogen sulfide corrosion-resistant petroleum drill pipe body steel with a yield strength of over 120ksi (827MPa) and a manufacturing method thereof. By adopting the steel grade and the production process of the invention, the high-strength hydrogen sulfide corrosion-resistant petroleum drill pipe can be produced with a yield strength of more than 120ksi (827MPa). Background technique [0002] The traditional main process of producing sulfur-resistant drill pipe is: thicken the two ends of the hot-rolled seamless steel pipe according to the required size, and then perform overall quenching and tempering heat treatment to make a qualified drill pipe body. After the heat-treated tool joint and the drill pipe body are connected by friction butt welding, they are welded and heat-treated, and finally processed into oil drill pipes by proper machin...

AI Technical Summary

Problems solved by technology

[0005] As far as the tool joint steel grade of sulfur-resistant drill pipe is concerned, if the composition design of the same steel grade as the pipe body is adopted, since the wall thickness of the joint is much thicker than that of the pipe body, the am...

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