Continuous casting type large-wall-thickness hot-rolled steel plate for deep sea pipelines and production method thereof

Abstract

The invention discloses a continuous casting type large-wall-thickness hot-rolled steel plate for deep sea pipelines and a production method thereof, and belongs to the technical field of pipeline steel. The hot-rolled steel plate is composed of, by weight, 0.03-0.06% of C, 0.15-0.30% of Si, 1.20-1.35% of Mn, smaller than or equal to 0.010% of P, smaller than or equal to 0.0012% of S, 0.01-0.05% of Alt, 0.03-0.05% of Nb, 0.00-0.05% of V, 0.005-0.016% of Ti, 0.25-0.40% of Ni, 0.00-0.30% of Cr, 0.00-0.20% of Cu, 0.00-0.15% of Mo and the balance Fe and inevitable impurity elements. Continuous castings with the thickness being 400 mm are adopted for producing the steel plate with the thickness being 41-48 mm. The steel plate and the production method thereof have the advantages that good metallographic structures are obtained, the Charpy impact toughness at -20 DEG C, the drop hammer toughness at -20 DEG C, the low yield ratio, the high uniform elongation rate, the anti-fracture toughness property CTOD, the A solution acid resistance HIC and SSCC, and the like of the large-wall-thickness hot-rolled steel plate for the deep sea pipelines are realized, and therefore the construction requirement of conveying pipelines of oil and gas fields of deep seas can be met.

Description

technical field [0001] The invention belongs to the technical field of pipeline steel, in particular to a hot-rolled steel plate for continuous casting slab with large wall thickness and deep sea pipeline and a production method thereof. The product has low yield ratio, high uniform elongation, excellent low temperature toughness, fracture toughness, and acid resistance, and is suitable for the construction of pipelines for deep sea oil and gas fields. Background technique [0002] With the implementation of the national marine strategy power, the exploitation of oil and gas resources began to extend to the ocean, especially the deep sea area. According to statistics, there are only 28 billion tons of oil reserves in waters with a water depth of less than 200m, while deep sea waters with a depth of more than 200m are estimated to have oil reserves of 300 billion tons. As of 2015, the production of deep-sea oil fields has reached 25% of all offshore production, and the produ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a hot-rolled steel plate for continuous casting slab with large wall thickness for deep-sea pipelines and its production method, which solves the problems of -20°C Charpy impact toughness and -20°C drop weight DWTT of hot-rolled steel plates for large-wall-thickness deep-sea pipelines. Toughness, low yield ratio, high uniform elongation, fracture toughness CTOD, A solution acid resistance HIC and SSCC, etc., to meet the construction of pipelines for deep-sea oil and gas fields

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