Thick-specification X65 pipeline steel and production method thereof

Abstract

The invention discloses thick-specification X65 pipeline steel and a production method thereof, and particularly relates to the thick-specification X65 pipeline steel and the production method thereof in the field of steel band production. The invention provides the thick-specification X65 pipeline steel with the advantages that the process is simple; the qualification rate is high. The weight percentage of chemical ingredients is shown as follows: C accounts for 0.03 to 0.06 percent; Si accounts for 0.10 to 0.30 percent; Mn accounts for 1.40 to 1.60 percent; the content of P is at most 0.020 percent; the content of S is at most 0.010 percent; Nb accounts for 0.030 to 0.039 percent; V accounts for 0.06 to 0.08 percent; Ti accounts for 0.008 to 0.019 percent; Cr accounts for 0.15 to 0.30 percent; the rest is Fe and unavoidable impurities. The invention also provides the production method of the thick-specification X65 pipeline steel with high qualification rate. The method comprises the following steps of melting and coarse milling, fine milling and cooling. The production method has the advantages of low production cost and high production efficiency.

Description

technical field [0001] The invention relates to a thick gauge X65 pipeline steel and a production method thereof, in particular to a thick gauge X65 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

The C content of this invention is relatively high. If the coiling temperature is lower than 560°C, a bainite structure will appear. If the coiling temperature is higher than 630°C, the core structure will be thick, which will affect its drop hammer performance. In the large-scale production of hot continuous rolling, due to the large fluctuation of coiling temperature of thick-gauge products, the pass rate of its performance is not high

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