Steel plate with low density and high marine environment resistance and production technology thereof

A marine environment, low-density technology, applied in the field of low-alloy corrosion-resistant steel medium and thick plates (60mm), can solve the problems of insignificant corrosion resistance in marine environments, low strength levels, and reduced corrosion rates to achieve corrosion resistance Remarkable performance, low production cost, and improved corrosion performance

Inactive Publication Date: 2014-04-23
UNIV OF SCI & TECH BEIJING +1
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  • Abstract
  • Description
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Problems solved by technology

[0004] Among the published patents on corrosion-resistant steel for marine environments, CN 101319293A published on December 10, 2008 introduced a seawater corrosion-resistant steel and its production process. The chemical composition of its molten steel is as follows: C 0.070~0.120, Mn 0.500~0.650, P 0.000~0.020, S 0.000~0.015, Si 0.250~0.450, Cr 0.800~1.200, Mo 0.200~0.300, Alt 0.450~0.600, Ti 0.006~0.02, the balance is Fe Unavoidable impurities, the seawater corrosion-resistant alloy system of this steel is the French APS series, and its main corrosion-resistant component is Cr-Mo-Al. The problem is that the strength level of this steel is low, and its corrosion resistance is affected. The type and content of corrosion-resistant elements are limited, and the improvement of corrosion resistance in marine environments is not obvious
[0005] CN 101389782A of JFY Steel Co., Ltd. published on March 18, 2009 and Chinese patent CN 102400059A published on April 4, 2012 both disclose a corrosion-resistant steel plate suitable for ship ballast tanks. The highest content of Al element in each patent is 0.1%. Among them, the Chinese patent CN 102400059A adds Ni element on the basis of Cr-Mo-Al series, and the CN 101389782A of Japan Jiefuyi has many kinds of corrosion-resistant elements, involving Cr- Al-W-Sn-Sb-Ni-Mo-Co, the corrosion-resistant steel invented by these two patents is suitable for the corrosive environment of ship ballast tanks. Generally, the bottom plate of the ballast tank will be covered by a layer of oil film. It is oil sludge and accumulated water. Usually, the existence of oil film has a protective effect on the bottom plate and will reduce the corrosion rate

Method used

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  • Steel plate with low density and high marine environment resistance and production technology thereof
  • Steel plate with low density and high marine environment resistance and production technology thereof
  • Steel plate with low density and high marine environment resistance and production technology thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 11

[0050] Embodiment 1.1: 20mm thick steel plate and its production process:

[0051] According to the chemical composition requirements of steel in the present invention, the chemical composition (wt%) obtained is shown in the following table 1:

[0052] .

[0053] The molten steel is cast into 250mm thick slabs, cut to length and then stacked and cooled slowly to room temperature, and the slabs are heated to 1200°C for 4.5 hours in the furnace.

[0054] The process of controlled rolling and controlled cooling is:

[0055] The starting temperature of rough rolling is 1000~1010℃, three times the thickness of the intermediate billet is adopted, 250mm→60mm, and the pressure rate of the last two passes of rough rolling is guaranteed to be greater than 20%. When the starting temperature is 940~950℃, the finishing temperature is 910~920℃, rolled into 20mm thick steel plate, the starting cooling temperature after rolling is 880~890℃, the final cooling temperature is 730~740℃, after...

Embodiment 12

[0056] Embodiment 1.2: 16mm thick steel plate and its production process

[0057] Adopt chemical composition and slab casting process identical with embodiment 1.1, its technology of controlled rolling and controlled cooling is:

[0058] The starting temperature of the rough rolling is 1000~1010℃, and the thickness of the intermediate billet is three times, 250mm→48mm, to ensure that the pressure rate of the last two passes of the rough rolling is greater than 20%. When the rolling start temperature is 940~950°C, the finish rolling end temperature is 910~920°C, rolled into a 16mm thick steel plate, the starting and cooling temperature after rolling is 880~890°C, and the final cooling temperature is 730~740°C. Stacking slow cooling, its mechanical properties are shown in Table 2.

[0059] Table 2 Mechanical properties of the steel plates of Example 1.1 and Example 1.2

[0060] .

Embodiment 21

[0061] Embodiment 2.1: 24mm thick steel plate and its production process:

[0062] According to the chemical composition requirements of steel in the present invention, the obtained chemical composition (wt%) is shown in the following table 3:

[0063] .

[0064] The molten steel is cast into 250mm thick slabs, cut to length and then stacked and cooled slowly to room temperature, and the slabs are heated to 1200°C for 4.5 hours in the furnace.

[0065] The controlled rolling and controlled cooling process adopted is:

[0066] The starting temperature of the rough rolling is 1010~1030℃, and the thickness of the intermediate billet is three times that of 250mm→72mm to ensure that the pressure rate of the last two passes of the rough rolling is greater than 20%. When the starting temperature is 930~940℃, the finishing temperature is 900~910℃, rolled into 24mm thick steel plate, the starting cooling temperature after rolling is 870~880℃, the final cooling temperature is 7...

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Abstract

The invention relates to a steel plate with low density and high marine environment corrosion resistance and a production technology thereof. The steel plate contains the following chemical ingredients by weight: 0.03-0.10 of C, 0.1-0.8 of Si, 0.5-1.5 of Mn, not more than 0.015 of P, not more than 0.005 of S, 0.1-2.0 of Al, 0.01-0.30 of Sn, 0.1-0.8 of Cr, 0.1-0.5 of Ni, 0.05-0.45 of Mo, 0.01-0.05 of Ti and the balance of Fe and unavoidable impurities. The production technology comprises a rotary furnace smelting procedure, an LF refining procedure, a vacuum degassing procedure, a continuous casting procedure, a controlled-rolling and controlled-cold procedure and the like. The structure type of the steel plate is theoretically a single-phase polygonal ferrite fine structure, but contains an extreme small quantity of unavoidable pearlite structure during actual industrial production. The marine environment (marine atmosphere, tidal range, total immersion and the like) corrosion resistance can be improved by near 70% than that of an EH36 ship structure in the same service environment, and the steel plate has excellent obdurability matching and welding performance. The steel plate has the advantages of simple production technology, low production cost, stable performance, excellent surface quality and great improvement on marine environment corrosion resistance.

Description

technical field [0001] The invention belongs to the field of manufacturing low-alloy corrosion-resistant steel medium and thick plates (60mm), in particular to a low-density high-corrosion-resistant steel plate in marine environments (marine atmosphere, tidal range, and full immersion) and a production process thereof. Background technique [0002] The report of the 18th National Congress of the Communist Party of China stated, "Improve the ability to develop marine resources, develop the marine economy, protect the marine ecological environment, resolutely safeguard the country's marine rights and interests, and build a powerful marine country." The important strategic decision made by the economic situation has pointed out the direction for the development of my country's marine industry. In the high-end equipment manufacturing industry in the "Decision of the State Council on Accelerating the Cultivation and Development of Strategic Emerging Industries", it is proposed tha...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/50C21D8/02
Inventor 于浩周涛李海旭
Owner UNIV OF SCI & TECH BEIJING
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