Thick X42 pipeline steel and production method thereof

Abstract

The invention discloses thick X42 pipeline steel and a production method thereof, and particularly relates to thick X42 pipeline steel and a production method thereof which are applied to the field of production of hot-continuous-rolled steel strips. The thick X42 pipeline steel low in production cost comprises, by weight, 0.03%-0.07% of C, 0.10%-0.30% of Si, 0.70%-1.00% of Mn, 0-0.020% of P, 0-0.010% of S, 0.015%-0.030% of Nb, 0.008%-0.019% of Ti, 0.15%-0.30% of Cr, and the balance Fe and inevitable impurities. The invention further provides the production method of the thick X42 pipeline steel. The production method of the thick X42 pipeline steel comprises the following steps of smelting and continuous casting, rough rolling, finish rolling, and double-section cooling. According to the thick X42 pipeline steel and the production method thereof, the production cost is relatively low, and the control difficulty is low.

Description

technical field [0001] The invention relates to a thick gauge X42 pipeline steel and a production method thereof, in particular to a thick gauge X42 pipeline steel and a production method thereof applied in the field of hot continuous rolling steel strip production. Background technique [0002] Pipeline transportation is the most economical way to transport oil and natural gas over long distances, and it is characterized by high efficiency, economy, safety and no pollution. In order to ensure the stability and safety of pipeline transportation, long-distance, high-pressure pipelines usually use thick-walled pipes. [0003] Oil and gas transmission pipes often pass through densely populated areas, and their safety is particularly important. Therefore, the comprehensive performance requirements of pipeline steel for oil and gas transmission pipes are high, requiring high toughness, low ductile-brittle transition temperature, good welding performance, etc., especially for crac...

AI Technical Summary

Problems solved by technology

This invention has a high C content, if the coiling temperature is lower than 540°C, a bainite structure will appear, and if the coiling temperature is higher than 580°C, the core structure will be coarse, which will affect its drop hammer performance

At the same time, its coiling temperature control range is narrow, and in large-scale hot rolling production, because the coiling temperature of thick-gauge products fluctuates greatly, this invention can produce X42 pipeline steel with a thickness of less than 12mm, but X42 with a thickness of more than 12mm can be produced. Pipeline steel, its drop hammer performance pass rate is not high

[0005] Patent CN 102622123 A discloses a manufacturing process of ultra-low carbon X42 steel grade high-frequency straight seam welding, and its invention claims only include the manufacturing process of high-frequency straight seam welding, excluding the chemical composition and production process of the base material , but it is mentioned in the content of the invention that the steel for ultra-low carbon X42 steel grade high-frequency longitudinal welded pipes can use the following components: C: 0.033-0.06%, Si: C: 0.18-0.22%, Mn: 1.04-1.2%, P: C: 0.0064~0.015%, S: 0.0006~0.0024%, Nb: 0.018~0.022%, Ti: 0.012~0.018%, Mo: 0.04~0.08%, the content of Mn in its chemical composition is high, and it contains a certain amount of The precious element Mo, and its S content requirements are strict, and deep desulfurization is required in the production process, so the production cost of the base material used in this invention is high

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