High-strength thick steel plate for large-scale petroleum storing tank and low-cost manufacturing method thereof

Abstract

The invention relates to a method for preparing a high strength thick steel plate for a large oil storage tank in a low cost, the method particularly applies to a high strength thick steel plate for a large oil storage tank, which is welded by line energy which is equal or less than 120 KJ / cm. The weight percentages of chemical constituents are that carbon is 0.01-0.12 percent, silicon is 0.15-0.35 percent, manganese is 1.45-1.80 percent, phosphorus is equal or less than 0.010 percent, sulfur is equal or less than 0.003 percent, aluminum is 0.02-0.06 percent, vanadium is 0.02-0.06 percent, nickel is 0.20-0.40 percent, nitrogen is 0.003-0.006 percent, and the other is ferric, other alloying elements and inevitable impurities. The invention uses on-line quenching and off-line tempering processes, thereby reducing valuable alloying elements, obtaining high strength high toughness thick steel plate which has excellent welding performance and does not need to preheat above 0 DEG C, reducing the producing cost, saving energy, increasing production efficiency and improving welding construction conditions, and the invention is capable of being widely used for constructions of a 10-30 cubic myriametre of large oil storage tank.

Description

technical field [0001] The invention belongs to the field of steel plate low-alloy steel production technology, and relates to a high-strength thick steel plate for large oil storage tanks and a manufacturing method thereof, in particular to a high-strength steel plate for oil storage tanks suitable for welding with 80-120KJ / cm large heat input . Background technique [0002] With the continuous demand for energy, the construction of oil storage tanks at home and abroad continues to develop and develop towards large-scale, 100,000 to 300,000 m 3 The construction of large oil storage tanks has entered a peak period. The medium in the oil storage tank is flammable and dangerous, and the steel required for the construction of the storage tank must be certified by the authoritative quality inspection department designated by the state before it can be used. [0003] In order to reduce material and manufacturing costs, high-strength quenched and tempered plates are mainly used ...

AI Technical Summary

Problems solved by technology

The off-line quenching and tempering production process is complex, with many links, poor surface quality, high production cost, long cycle, and difficult to guarantee delivery time; the TMCP process is affected by cooling conditions, and the performance stability of the steel plate is poor

[0012] (4) Contains more expensive metals, and the alloy cost is higher

Rare earth elements are very active elements, not easy to control, and easy to pollute molten steel, which is not conducive to the improvement of product quality

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