Economical X65 petroleum and gas pipeline steel and production method thereof

Abstract

The invention discloses economical X65 petroleum and gas pipeline steel. The economical X65 petroleum and gas pipeline steel comprises, by weight, 0.10-0.14% of C, 0.15-0.40% of Si, 1.10-1.40% of Mn, less than or equal to 0.015% of P, less than or equal to 0.0020% of S, 0.025-0.045% of Nb, 0.041-0.060% of V, 0.005-0.020% of Ti, 0.020-0.050% of Al, and less than or equal to 0.008% of N. The production method comprises the following steps of carrying out melting and pouring blank-molding, heating the casting blank, carrying out rough rolling by a wide-heavy plate mill, carrying out two-stage finish rolling by the wide-heavy plate mill, carrying out cooling and carrying out straightening. The economical X65 petroleum and gas pipeline steel has a price reduced by greater than or equal to 5%, and has steel plate yield strength (R<t 0.5>) greater than or equal to 450MPa, tensile strength (Rm) greater than or equal to 535MPa, yield ratio (R<t 0.5> / Rm) less than or equal to 0.91, elongation percentage (A50mm) greater than or equal to 24%, -20 DEG C KV<2> greater than or equal to 200J and -15 DEG C DWTT SA greater than or equal to 85%.

Description

technical field [0001] The invention relates to a pipeline steel and a production method thereof, in particular to an X65 grade oil and gas pipeline steel and a production method thereof. Background technique [0002] With the rapid development of the world economy, the demand for energy resources such as oil and natural gas is increasing day by day, and the construction of oil and natural gas long-distance pipelines and urban pipeline networks has been vigorously developed. In order to improve the transmission efficiency and operation economy of long-distance pipelines and urban pipeline networks, in recent years, the transmission pressure and diameter of pipelines have been increasing, and the requirements for the strength and toughness of pipeline steel raw materials are getting higher and higher. [0003] At present, the main lines of major long-distance pipelines at home and abroad all use X70 and X80 grade pipeline steel, and the material selection of branch lines and ...

AI Technical Summary

Problems solved by technology

The deficiencies in this document are: the addition of higher content of Nb and V makes the production cost high, and also requires relaxation between rough rolling and finish rolling, resulting in not only low production efficiency, but also increased indirect production costs

Although it can be used as a substitute for steel for oil pipelines, it still contains expensive Cu and Mo elements, and the heating temperature of the slab is high, resulting in high energy consumption

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