X70-degree large deformation resisting pipeline steel plate with excellent tenacity and preparation method for pipeline steel plate

Abstract

The invention provides an X70-degree large deformation resisting pipeline steel plate with excellent tenacity and a preparation method for the pipeline steel plate, and belongs to the technical field of low-carbon micro-alloy steel. The pipeline steel plate comprises the following chemical constituents by weight percent: 0.03 to 0.08 percent of C, 0.10 to 0.45 percent of Si, 1.40 to 1.69 percent of Mn, 0 to 0.015 percent of P, 0 to 0.005 percent of S, 0.01 to 0.06 percent of Alt, 0.01 to 0.05 percent of Nb, 0.004 to 0.014 percent of Ti, 0 to 0.008 percent of N, and 0 to 0.0002 percent of H, and further comprises one to four types of the following chemical constituents by weight percent: 0 to 0.30 percent of Mo, 0 to 0.30 percent of Ni, 0 to 0.30 percent of Cr, 0 to 0.30 percent of Cu, andFe and unavoidable impurity elements in balancing amount. The preparation method comprises the following steps: revolving furnace smelting, outside furnace refining, continuous casting, heating, controllable rolling, accelerated cooling, and the like. The pipeline steel plate has the advantages of excellent tenacity and large deformation resistance, thereby being widely applied to land liquefaction subsidence and ground landslide deformation in a seismic area caused by a permafrost as well as to pipeline engineering such as deep sea pipeline laying where severe plastic deformation can be caused easily.

Description

technical field [0001] The invention belongs to the technical field of low-carbon micro-alloy steel, and in particular relates to a X70-grade anti-large deformation pipeline steel plate with excellent toughness and a preparation method thereof, which are suitable for harsh environments such as seismic zones, permafrost layers, landslide areas, and oceans. Oil and natural gas transmission pipeline engineering construction. Background technique [0002] Since oil and natural gas resources are mostly concentrated in remote areas with relatively harsh environments such as deserts, seismic zones, permafrost, landslides, and oceans, oil and gas are transported in earthquake-prone and permafrost geologically, and ground displacement induces large strains. Highly machined formed tubing requiring buckling resistance. The design of the pipeline not only needs to carry out the stress design, but also should fully consider the design of the strain capacity. This kind of pipeline steel ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a X70 grade anti-large deformation pipeline steel plate with excellent toughness and its preparation method, which overcomes the high production cost caused by adding a large amount of precious alloys Mo, Ni, Nb, etc. in the prior art and the low low temperature impact toughness And other issues

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