Steel for anticorrosion sucker rods in oil field and production method thereof

Abstract

The invention relates to a steel for anticorrosion sucker rods in an oil field and a production method thereof, belonging to the technical field of steel for oil fields. The steel provided by the invention comprises the following chemical components: 0.20-0.30% of C, 0.10-0.40% of Si, 0.60-1.00% of Mn, 0.40-0.80% of Cr, at most 0.10% of Mo, 0.60-1.00% of Ni, and the balance of Fe and inevitable impurity. The steel can be produced in a steel plant having converters, refining equipment outside ladle furnaces (LFs) and fully-protected casting conditions; the quality indexes of steel, such as purity and the like, are controlled by smelting and continuous casting; the rolled stock can obtain fine and uniform structure and grain fineness, excellent surface quality and the like by rolling; and different heat treatments are carried out in the processing process to finally respectively obtain a KD-level sucker rod of which Rm is 795-965 MPa, Rel is greater than or equal to 590 MPa and A200 is greater than or equal to 10%, and an H-level sucker rod of which Rm is 965-1195 MPa, Rel is greater than or equal to 795 MPa and A200 is greater than or equal to 12%. The serial sucker rods have favorable corrosion resistance in oil fields in practical application.

Description

technical field [0001] The invention belongs to the technical field of oil field steel. In particular, it provides an anti-corrosion sucker rod steel for oil fields and its production method. Compared with similar products currently used at home and abroad, it has better corrosion resistance and more economical production cost. Background technique [0002] The sucker rod is an important part used to connect the surface pumping unit and downhole pumping in the oil production system of the oil field, and it is one of the important consumable materials in the oil extraction activities. In the process of oil production, the load on the sucker rod includes the weight of the sucker rod string, the weight of the liquid column, the inertial load of the sucker rod string and the liquid, the frictional resistance of the sucker rod string in motion, and the weight of the sucker rod string. Shock loads due to elasticity and shock loads due to inconsistent movement of the liquid and th...

AI Technical Summary

Problems solved by technology

Before the present invention, the KD and H grade sucker rods and their steel supply in the domestic market were all blank; foreign KD and H grade sucker rods were all made of 4620, 4330 and other steel grades, and the precious metal element Mo of this series of steel grades (0.20~0.30%) and Ni(1.65~2.00%) are high in content, and are mostly produced by electric arc furnace smelting, so the production cost and alloy cost are extremely high

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