Preparation method of 80-100mm extra-thick EH36 steel for offshore wind power

Abstract

The invention relates to a preparation method of 80-100mm extra-thick EH36 steel for offshore wind power. The preparation method comprises the following steps of: converter processing-LF refining-RH vacuum degassing-Ca treatment-continuous casting-casting blank hydrogen diffusion-heating-normalizing rolling-air cooling-steel plate stacking and slow cooling- unstacking, wherein the normalizing rolling adopts two stages of rough rolling and finish rolling; the initial rolling temperature of the rough rolling is 1050-1100 DEG C, the single-pass reduction rate of three passes after the rough rolling is greater than or equal to 15%, and the cumulative reduction rate in the rough rolling stage is greater than or equal to 50%; and the initial rolling temperature of the finish rolling is 860-890 DEG C, the austenite non-recrystallization interval is expanded by adding sufficient Nb, the initial rolling temperature of the finish rolling is above the austenite ferrite equilibrium transformationpoint Ac3, the total rolling pass is 8-12, air cooling is carried out after rolling, Nb is separated out in the steel plate in the air cooling process, and the triangular grain boundary, the grain boundary and the grain interior of ferrite grains are pinned to limit the rapid growth of the ferrite. Therefore, the normalized and rolled EH36 steel plate for offshore wind power is obtained.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a preparation method of extra-thick EH36 steel for offshore wind power by normalizing rolling. Background technique [0002] As a renewable energy source, wind power is regarded as the future of clean energy. Wind power provides clean energy for households and businesses, reduces climate change, reduces carbon pollution, and increases international economic competitiveness. Offshore wind power is growing rapidly worldwide due to continued lower prices and more efficient wind power generation. [0003] The increase in demand for offshore wind power has led to the strong development of large-thickness offshore wind power steel used to make wind power pipe piles and jackets. Wind turbine sizes continue to increase due to the need to reduce the levelized cost of electricity generated by offshore wind projects. The larger the fan, the larger the inner diameter o...

AI Technical Summary

Problems solved by technology

Chinese patent document CN106521319A discloses a kind of extra-thick EH36 steel for offshore wind power pipe piles and its preparation method. The performance meets the requirements of GB712 and classification society specifications. Production time and economic cost

In addition, Chinese patent CN106521319A added a large amount of precious micro-alloys Nb, V and Ni in order to ensure that the strength of steel plates with a thickness of 90-120mm can still meet the requirements after normalizing, and the carbon equivalent is relatively high. Increased alloy cost

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