Carbon dioxide corrosion-resistant pipeline steel and preparation method thereof

Abstract

The invention discloses pipeline steel resistant to carbon dioxide corrosion and a preparation method thereof, and belongs to the technical field of pipeline steel manufacturing. The pipeline steel comprises the following chemical components: not more than 0.05 percent of C, 0.2-0.3 percent of Si, 0.50-0.80 percent of Mn, not more than 0.020 percent of P, not more than 0.010 percent of S, 4.0-7.0 percent of Cr, not more than 0.080 percent of Nb, not more than 0.050 percent of Ti, not more than 0.080 percent of V, 0.2-0.50 percent of Mo, not more than 0.30 percent of Ni, not more than 0.5 percent of Cu, not more than 0.010 percent of N, not more than 0.0010 percent of B and the balance of Fe and impurities. A higher-toughness steel plate of the pipeline steel resistant to the carbon dioxide corrosion is obtained finally through the processes such as smelting, casting, forging and pressing, heating, rolling, cooling, quenching and tempering. The production process is simple, the operation is feasible, the production cost is low, the corrosion rate of the steel can be lowered to 0.0581 mm / a, the yield strength is greater than 500 MPa, the tensile strength is greater than 550 MPa, the elongation is greater than 25 percent, the impact energy at the temperature of minus 20 DEG C is greater than 150 J, and the DWTT mean value at the temperature of minus 20 DEG C is 100 percent.

Description

technical field [0001] The technology relates to a pipeline steel and a manufacturing method thereof, which mainly involves the preparation of a carbon dioxide corrosion-resistant steel. The process adopts the principle of low-C, low-Cr microalloying, controlled rolling and controlled cooling, and appropriate heat treatment process, and uses grain refinement and precipitation of microalloying elements to make the steel have good mechanical properties. Alloying enables the formation of a complete protective corrosion product film on the surface of the pipeline steel and fully improves the carbon dioxide corrosion resistance of the pipeline steel. Background technique [0002] In recent years, with the continuous development of deep oil and gas wells and the wide application of carbon dioxide flooding enhanced oil recovery technology, the gas contained in the produced fluid of oil and gas wells has increased. Carbon dioxide often exists in oil and gas as one of the components...

AI Technical Summary

Problems solved by technology

Carbon dioxide corrosion may greatly shorten the actual service life of the pipeline, cause early corrosion failure, and cause serious corrosion damage such as pitting and perforation on the surface of the pipeline. Whether at home or abroad, carbon dioxide corrosion has become a problem that cannot be ignored

However, there are few research reports on carbon dioxide corrosion-resistant materials.

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