Large deformation resistant multiphase X100 high-strength steel plate for large diameter pipeline and manufacturing method for steel plate

Abstract

The invention belongs to the technical field of manufacturing of low-alloy high-strength pipeline steel, and particularly relates to a large deformation resistant multiphase X100 high-strength steel plate for a large diameter pipeline and a manufacturing method for the steel plate. The high-strength steel plate is prepared from the following components by weight percent: 0.04-0.08% of C, 0.15-0.35% of Si, 1.60-2.00% of Mn, less than or equal to 0.008% of P, less than or equal to 0.003% of S, 0.07-0.11% of Nb, 0.015-0.025% of Ti, less than or equal to 0.25% of Mo, less than or equal to 0.35% of Cu, less than or equal to 0.030% of Ni, less than or equal to 0.030% of Cr, and the balance of Fe and unavoidable impurities. The high-strength pipeline steel has the following benefits: the P content maximum value in the component design is 0.010%; the S content maximum value is 0.003%; the steel is purer; the high-niobium component design can significantly improve the crystal refinement and the strength of the steel plate, so that the noble metals such as Mo and Ni of the steel plate are reduced; the cost is lower; the energy saving and environmental protection effects are realized; the high-strength steel plate is suitable for material development direction, and easier to produce and promote. The yield strength of the steel plate is 690-760 MPa; the tensile strength is 870-920 MPa; the uniform ductility is greater than or equal to 10%; the yield ratio is less than or equal to 0.78; the Charpy impact power at -20 DEG C is greater than or equal to 300 J; the drop hammer tearing test shear area at -15 DEG C is greatert than or equal to 85%.

Description

technical field [0001] The invention belongs to the technical field of low-alloy high-strength pipeline steel manufacturing, and more specifically relates to a large-diameter pipeline anti-large deformation multi-phase X100 high-strength steel plate and a manufacturing method thereof. Background technique [0002] With the continuous demand for oil and natural gas energy at home and abroad, more and more long-distance oil and gas transmission pipeline projects are being constructed. Pipelines are developing towards large-diameter and high-pressure bearings. In order to reduce the cost of engineering construction materials, improving material strength and reducing pipe thickness have become the best means to reduce costs. Takeuchi's research proves that when other factors remain unchanged, as the strength of the steel pipe increases, the effective plasticity of the material decreases gradually, and its uniform elongation shows a downward trend. One of the most challenging ar...

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Problems solved by technology

[0006] Only 1) and 2) in the above patent documents are pipeline steels with large deformation resistance, and the rest are X100 pipeline steels designed based on stress. Low, especially without the requirement of uniform elongation, the safety is poor; while 1) the maximum S content in medium is 0.004%, 2) the maximum S content in medium is 0.005%, and the maximum P content is 0.015%. 1) The published product performance The lower limit of Charpy impact energy at -20°C is 150J, 2) The lower limit of Charpy impact energy at -20°C is 250J according to the published product performance

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