High-strength and low-yield ratio easy-to-weld movable pressure vessel steel plate and manufacturing method thereof

Abstract

The invention relates to a high-strength, low-yield-ratio, easy-to-weld mobile pressure vessel steel plate. The chemical composition of the steel plate is calculated by mass percentage, C: 0.14-0.20%, Si: 0.20-0.60%, Mn: 1.10-1.70%, P≤ 0.020%, S≤0.010%, Ni: 0.20~0.80%, Nb: 0.010~0.050%, V: 0.010~0.20%, 40ppm≤N≤80ppm, H≤2ppm, Pcm≤0.30, the balance is Fe and unavoidable of impurities. Manufacturing process: converter smelting→ladle furnace refining→vacuum treatment→continuous casting→slab heating→controlled rolling→controlled cooling→slow cooling→flaw detection→normalizing→performance inspection. The present invention adopts design concepts such as solid solution strengthening, fine grain strengthening and toughening, and the steel plate is delivered in a normalized state, integrating high strength, high toughness, low yield ratio, and excellent welding performance. It has excellent performance and short production cycle. Features such as low cost.

Description

technical field [0001] The invention belongs to the field of low-alloy high-strength steel products, in particular to a thin-gauge high-strength thin-gauge low-yield ratio high-toughness steel plate. Background technique [0002] At present, the tensile strength of steel used for mobile tank trucks (mobile pressure vessels) used in China is mostly less than 600MPa, the low-temperature impact toughness value is low, and the yield strength is relatively high, so the wall thickness of the tank body cannot adapt to the production of thin specifications, and the self-weight coefficient increases accordingly. The volume-to-weight ratio is small and the carrying efficiency is low. In recent years, with the continuous development of the petrochemical industry, the demand for mobile tankers with high strength, high toughness and low self-weight coefficient has become more and more urgent. [0003] Patent No. CN101144138A has invented a steel plate for low-temperature pressure vessel...

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Problems solved by technology

[0008] Aiming at the shortcomings of insufficient strength, poor welding ability and high yield ratio of the existing steel for mobile pressure vessels, the present invention provides a high-strength, high-toughness, easy-to-weld, low-yield ratio steel without increasing the specifications of the steel plate. The strength of the steel for mobile tank trucks of the present invention is obviously higher than that of steel for traditional mobile pressure vessels. It integrates high strength, high toughness at low temperature, low yield ratio and excellent welding performance, and has the advantages of strong production operability and low cost. features

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