Large-deformation-preventing pipeline steel with excellent aging resistance and production method thereof

Abstract

The invention discloses large-deformation-preventing pipeline steel with excellent aging resistance and a production method thereof. The pipeline steel comprises the following chemical components by weight percentage: 0.03 to 0.12 percent of C, 0.10 to 0.30 percent of Si, 1.20 to 1.80 percent of Mn, 0.010 percent of P or less, 0.005 percent of S or less, 0.030 to 0.060 percent of Nb, 0.006 to 0.020 percent of Ti, 0.10 to 0.40 percent of Cr, 0.10 to 0.30 percent of Ni, 0.01 to 0.03 percent of Cu, 0.010 to 0.050 percent of Al, and the balance of Fe and unavoidable impurity. The pipeline steel is fabricated by the controlled rolling and cooling technique, the heating temperature before rolling is 1150 to 1250 DEG C, the rough rolling temperature is 950 to 1050 DEG C, and the initial finish rolling temperature is 880 to 900 DEG C; the steel is subjected to laminar flow cooling after being rolled, the final cooling temperature is 600 to 650 DEG C, and the cooling rate is 5 to 15 DEG C per second; and finally, the steel is subjected to two-phase region quenching at the temperature between Ac1 and Ac3. The produced large-deformation-preventing pipeline steel is characterized by low yield ratio, high strength, high plasticity, high aging resistance and the like.

Description

technical field [0001] The invention relates to a large-deformation-resistant pipeline steel, in particular to a large-deformation-resistant pipeline steel with excellent aging resistance and a production method thereof. Background technique [0002] The use of pipelines to transport oil and gas has the characteristics of high efficiency, economy, safety, and no pollution, and is considered to be an effective way to transport oil and gas over long distances. In order to improve transportation efficiency, reduce energy consumption, reduce investment and reduce pipeline operating costs, on the one hand, long-distance pipeline transportation needs to increase the pipe diameter, reduce unit transportation costs, and increase the strength level of pipeline steel; on the other hand, it is necessary to consider the topography Complexities such as seismic zones and permafrost. Buried pipelines in these areas may undergo large plastic deformation. These two aspects constitute the l...

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Problems solved by technology

Its production process is also relatively complicated, requiring the rolling deformation in the non-recrystallization area to be greater than 30%, and there are requirements for the final rolling temperature and post-rolling cooling rate, and then the hot-rolled sheet needs to be quenched and tempered, and the aging is not investigated. performance

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