A normalized corrosion-resistant wind power steel with yield strength ≥ 440mpa and production method

Abstract

The invention relates to a normalized corrosion-resistant wind power steel with yield strength of at least 440 MPa. The wind power steel is composed of the following components in percentage by weight: 0.06-0.13% of C, 0.22-0.38% of Si, 0.98-1.25% of Mn, at most 0.015% of P, at most 0.008% of S, 0.030-0.040% of Als, 0.040-0.070% of Nb, 0.05-0.08% of V, 0.40-0.48% of Cr and 0.20-0.25% of Ni. The production method comprises the following steps: smelting, carrying out continuous casting to obtain a billet, and heating; carrying out two-stage rolling; cooling with water; and normalizing. The hot rolling+normalized condition delivery is adopted to produce the steel plate; and after the normalizing, the yield strength is at least 440 MPa, the tensile strength is 520-680 MPa, the elongation percentage A is at least 30%, and the -50-DEG C KV2 is at least 200J. The wind power steel can be widely used in wind power generation tower engineering steel structures.

Description

technical field [0001] The invention relates to a wind power steel and a production method thereof, in particular to a high-strength corrosion-resistant normalized wind power steel and a production method thereof. Background technique [0002] In March 2015, the National Development and Reform Commission, the Ministry of Foreign Affairs, and the Ministry of Commerce jointly issued the "Vision and Actions to Promote the Joint Construction of the Silk Road Economic Belt and the 21st Century Maritime Silk Road." The plan proposes to actively promote cooperation in clean and renewable energy such as hydropower, nuclear power, wind power, and solar energy, promote cooperation in the processing and transformation of energy resources in the local area, and form an integrated upstream and downstream industrial chain of energy resource cooperation. It can be seen from the plan that references to energy and infrastructure are closely related to wind power. With the help of the "Belt ...

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Problems solved by technology

[0005] The Chinese Patent Publication No. CN101413049A discloses a preparation method of a normalizing weldable fine-grained steel plate with a yield strength of 420 MPa. The invention adopts a controlled rolling + normalizing process. The steel of the invention has better low-temperature impact properties, but Its yield strength is 425~465MPa, the margin is not large, and the invention steel does not require corrosion resistance

The invention steel adopts two-stage rolling, the yield strength is 430~460MPa, the impact toughness is good, and it has a certain corrosion resistance, but its yield strength margin is average, and if it is normalized, its strength will be greatly reduced, and it cannot reach 420MPa class

[0009] It can be seen from the 420MPa grade normalized steel and wind power steel disclosed in the above patents that the normalized heat treatment process can meet the requirements of the invention steel with a strength of 420MPa grade, but its strength margin is not large, the elongation A is low, and low temperature impact The work is also low, and the corrosion resistance of steel is not considered, but the anti-corrosion coating is used when it is used at sea, resulting in a large amount of maintenance work in the later period

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