Steel plate with yield strength larger than or equal to 550MPa and low yield ratio and for large oil storage tank and production method of steel plate

Abstract

The invention belongs to the technical field of microalloyed steel production, and provides a steel plate with the yield strength larger than or equal to 550MPa and the low yield ratio and for a large oil storage tank and a production method of the steel plate. The steel plate comprises, by weight percentage, smaller than or equal to 0.10% of C, 0.20%-0.35% of Si, 1.30%-1.50% of Mn, smaller than or equal to 0.012% of P, smaller than or equal to 0.003% of S, 0.15%-0.30% of Ni, 0.010-0.030% of Nb, smaller than or equal to 0.05% of V, smaller than or equal to 0.030% of Ti, 0.08%-0.20% of Mo, 0.020%-0.050% of Al, smaller than or equal to 0.003% of N, smaller than or equal to 0.0050% of As, smaller than or equal to 0.0002% of [H], smaller than or equal to 0.0025% of [O], smaller than or equal to 0.40% of controlled CEV, smaller than or equal to 0.20% of Pcm and the balance Fe and inevitable inclusions. The steel grade well meets the requirement for development of the large oil storage tank construction industry, the material support is provided for large-scale development of the oil storage tanks in China and guarantee of the energy safety in China, and a green and high-surface-quality-assurance-capacity technological approach is provided for production of the steel plate for the high-strength large oil storage tank.

Description

technical field [0001] The invention belongs to the technical field of micro-alloy steel production, and relates to a steel plate for large-scale oil storage tanks with yield strength ≥ 550 MPa, low yield ratio, and easy welding, and a production method thereof. Provide material support, and at the same time provide a green and high surface quality assurance process for the production of steel plates for high-strength large oil storage tanks. Background technique [0002] The intensification of energy demand and the rapid development of modern industry have made the strategic importance of oil to the development of modern industry increasingly prominent. Oil reserves are crucial to ensuring energy security. Therefore, countries all over the world, especially industrially developed countries, have stockpiled crude oil. With the advancement of the oil reserve system, the number of large oil storage tanks around the world is increasing year by year, and the volume of a single s...

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Problems solved by technology

At present, many steel factories in China are able to produce high-strength steel plates for storage tanks, and various technical indicators have reached the advanced level of similar foreign products. However, steel oil storage tanks are a large thin-walled welded container assembled and welded on site. The volume of crude oil storage tank increases, the construction cost, difficulty and scale increase, and then there are higher requirements for the safety margin of the built storage tank, which is reflected in the steel materials: higher strong plasticity, lower yield Strength ratio, better welding performance and surface quality, especially the requirements of low yield ratio have been put forward in more and more storage tank construction engineering design schemes, but there is no clear requirement for this indicator in the national standard

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