M65-grade electric resistance welding oil casing pipe and manufacturing method thereof

Abstract

The invention relates to the technical field of oil casing pipes, in particular to an M65-grade electric resistance welding oil casing pipe and a manufacturing method thereof. The M65-grade electric resistance welding oil casing pipe comprises the following chemical components in percentage by weight: 0.19%-0.23% of C, 0.15%-0.30% of Si, 1.30%-1.50% of Mn, less than or equal to 0.020% of P, less than or equal to 0.008% of S, 0.05%-0.08% of Ti, 0.03%-0.06% of V, 0.02%-0.05% of Als, less than or equal to 0.008% of N and the balance Fe and inevitable elements. The manufacturing method comprises the steps: 1) a smelting continuous casting technology; 2) a rolling process: heating a continuous casting sheet billet to 1150-1200 DEG C by a heating furnace, and then rolling by adopting hot continuous rolling at the final rolling temperature of 800-860 DEG C; 3) cooling a rolled steel strip at the speed of 6-12 DEG C / s, and coiling the steel strip at the temperature of 500-590 DEG C; 4) welding the steel strip into a steel pipe; (5) carrying out heat treatment on the whole steel pipe: after ERW pipe manufacturing, heating the whole pipe to 870-900 DEG C, and carrying out heat preservation for 30-50 min and air cooling; and then tempering the whole pipe, wherrin the tempering temperature is 500-560 DEG C, heat preservation is conducted for 60-80 min, and then water cooling is conducted. The heat treatment process is simplified, it is guaranteed that the steel pipe has better weldability and impact toughness, brittle failure of an oil well pipe can be prevented, and higher safety is achieved.

Description

technical field [0001] The invention relates to the technical field of petroleum casing, in particular to an M65 grade electric resistance welded petroleum casing and a manufacturing method thereof. Background technique [0002] Oil casing is one of the most commonly used oil-specific pipes in oil fields. The annual demand is about 800,000 to 1 million tons, accounting for more than 40% of the total steel used in the oil industry. It is an indispensable construction in oil and gas field drilling operations. Material. Compared with seamless pipes, HFW casings have significant advantages such as uniform wall thickness, high dimensional accuracy, good perforation performance, strong collapse resistance, and low cost. The replacement of traditional seamless steel pipe by ERW casing is the future development trend. The research and development of high value-added, different grades of straight seam welded casings for oil layers can improve market competitiveness, which has far-r...

AI Technical Summary

Problems solved by technology

The paper discloses the seamless pipe M65, which adopts a high-carbon design and has a carbon equivalent greater than 0.6. The weldability and impact toughness of the steel strip are poor.

[0005] At present, there are problems in the production of straight seam resistance welded petroleum casing M65: high carbon content, poor weldability and impact toughness of the steel strip, complex quenching and tempering heat treatment process, etc.

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