Corrosion-resistant 5Cr steel and production method thereof

Abstract

The invention discloses corrosion-resistant 5Cr steel and a production method thereof, belonging to the technical field of corrosion-resistant high-5Cr-content steel production. The steel comprises the following chemical components in percentage by mass: 0.05-0.07% of C, 0.1-0.3% of Si, 0.5-0.8% of Mn, less than or equal to 0.02% of P, less than or equal to 0.01% of S, 4.5-5.5% of Cr, 0.02-0.05% of N and the balance of Fe and unavoidable impurities. The production method of the corrosion-resistant steel comprises the steps of molten iron preparation; converter smelting; ferrochrome adding; refining; continuous casting of small square billets; heating furnace heating; controlled rolling; and controlled cooling. The corrosion-resistant 5Cr steel produced by using the method has the yield strength of 600Mpa and a thin stripped martensite. The corrosion-resistant 5Cr steel has the advantages of excellent chloride ion corrosion resistance 2-3 times as high as that of carbon steel, excellent industrial atmospheric corrosion resistance and suitability for a concrete structure with requirements for ultrahigh strength and durability design under bad conditions such as sea, wetlands and the like; and in addition, the cost of the corrosion-resistant 5Cr steel is relatively low and is far lower than the cost of stainless steel, and therefore, the corrosion-resistant 5Cr steel as structural steel for a building is easier to popularize and use.

Description

technical field [0001] The invention belongs to the technical field of high-Cr corrosion-resistant steel, and in particular relates to a 5Cr corrosion-resistant steel and a production method thereof. Background technique [0002] The development of corrosion-resistant steel in my country is still in the initial stage. At present, the main corrosion-resistant steel in China is weather-resistant steel (SO 2 corrosion), seawater resistant steel (Cl -1 corrosion). The former can meet the corrosion resistance requirements by adding a certain amount of Cu-P alloy under general industrial environment conditions, while the latter is different, because the ability of chloride ions to penetrate the corrosion rust layer and the steel matrix is ​​strong, in the obvious The location of micro-defects and inclusions can quickly penetrate the corrosion matrix. Therefore, it is necessary to add a large amount of expensive alloys such as Ni, Cu, etc. in conjunction with Cr to delay the corr...

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Problems solved by technology

With the different uses of steel, the corrosion degree and durability of ordinary steel show obvious disadvantages: First, the use of ordinary construction steel in coastal areas, marine engineering, marsh engineering and other natural environments with very harsh environmental conditions has already It cannot meet the requirements of its service life; second, the current domestic construction materials are all made of sea sand, which is rich in a large amount of chloride ions, and the long-term erosion of the steel matrix in the concrete can greatly reduce the service life of the steel; third , even if the addition of Cu and Ni alloys can play a role in delaying corrosion, but its price is relatively expensive, the cost is greatly increased, and it is difficult to promote it in the field of construction steel

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