A kind of marine engineering steel with yield strength ≥ 450mpa and its preparation method

Abstract

The invention discloses ocean engineering steel with the yield strength larger than or equal to 450 MPa and a preparation method thereof. The steel comprises, by mass, 0.052-0.11% of C, 0.14-0.23% ofSi, 1.1-1.9% of Mn, 0-0.015% of P, 0-0.004% of S, 0.51-0.73% of Cr and the balance Fe and inevitable impurities. During preparation, the mass percentage of each chemical component in a molten iron tank is adjusted, then molten iron desulphurization, converter dephosphorization, alloying, refining desulphurization, external furnace Ar blowing refining and ingot casting are carried out, rolling is carried out in a rough rolling stage and in a fine rolling stage, and finally, watering is carried out for quick cooling to obtain the ocean engineering steel. The ocean engineering steel is simple inchemical component and production process, the production cost is low, the comprehensive mechanical property is good, the stability in an ocean environment is good, and application and popularizationprospects are good.

Description

technical field [0001] The invention relates to the technical field of alloy structural steel manufacturing, in particular to a marine engineering steel with yield strength ≥ 450 MPa and a preparation method thereof. Background technique [0002] The stability of marine engineering steel structures is often evaluated by "stiffness". Stiffness = strength × thickness. The higher the stiffness, the better the stability of the steel structure, which can resist external forces such as hurricanes and waves in the marine environment. The increase in the thickness of the steel makes processing more difficult, especially in the welding process, which requires preheating, resulting in a harsh working environment. Moreover, welded joints are prone to defects such as cracks, making it difficult to guarantee quality and performance, and there are potential safety hazards. At present, the steel used in marine engineering is mostly constructed of steel with a yield strength of 345MPa. In o...

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Problems solved by technology

[0007] The purpose of the present invention is to solve the problems of high cost of raw materials for steel used in marine engineering, the use of quenching + tempering process, complex process, poor surface quality of steel obtained, and low yield, and provide a marine steel with yield strength ≥ 450MPa. Engineering steel and its preparation method, the chemical composition and production process of the marine engineering steel of the present invention are simple, the production cost is low, the comprehensive mechanical properties are excellent, and it has good application and promotion prospects

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