High-formation, high-weather resistance, ultra-thin hot-rolled steel plate and its csp production process

Abstract

The invention discloses a high-formation, high-weather-resistance, ultra-thin specification hot-rolled steel plate and its CSP production process. The composition and weight content of the steel plate are as follows: C: 0.035-0.065%, Si: 0.15-0.3%, Mn: 1.3-1.6 %, Cu: 0.12-0.2%, Cr: 0.2-0.6%, Ni: 0.1-0.2%, Ti: 0.1-0.13%, Mo: 0.1-0.2%, Als: 0.025-0.045%, P: 0-0.018% , S: 0 ~ 0.005%, N: 0 ~ 0.006%, the rest is Fe and unavoidable impurities; the production process controls the converter smelting steel P is 0 ~ 0.012%; the crystallizer heat flow is 2.45 ~ 2.55mw / m 2 , the specific water volume of the continuous casting secondary cooling water is 1.77~1.83L / Kg, the thickness of the continuous casting slab is 65~75mm, and it is pressed down to 55~60mm by the liquid core for many times; the temperature of the casting slab is 1230~1250℃; The rolling temperature is 880-920°C; coiling is carried out after laminar flow cooling, adopting the head ladder cooling method, after coiling off-line, cooling to 280-320°C at a cooling rate of ≤10°C / S and then rapid cooling. The produced thin gauge steel plate has high formability while stably obtaining high strength and high weather resistance.

Description

technical field [0001] The invention relates to metallurgical technology, in particular to a hot-rolled steel plate with high profile, high weather resistance and ultra-thin specification and its CSP production process. Background technique [0002] WISCO's CSP production line is the latest generation of thin slab continuous casting and rolling production line. It was hot-tested in March 2009. The production line includes two 150-ton converters, two LF refining furnaces, one RH refining furnace, two-strand thin slab continuous casting line, Tunnel furnace and seven-stand hot rolling mill. The maximum slab width produced by the casting machine is 1680mm, and the thickness is 70mm and 90mm. The designed working speed of the machine can reach 5-6m / min. The annual design production capacity of hot-rolled strip steel of the entire production line is 2.5 million tons, of which 542,000 tons are for hot-rolled pickling and galvanized coils, 978,000 tons are raw silicon steel coils...

AI Technical Summary

Problems solved by technology

When the high-strength thin material is produced in batches on the CSP production line, due to the special shape of the funnel-shaped mold of the CSP continuous casting machine and the high content of alloy elements in the high-strength steel, the formability of the product needs to be improved; rolling thin steel plates requires liquid core pressing Under normal circumstances, the billet shell is easy to deform, and the risk of steel breakout is high, and the steel breakout rate reaches 40% at the highest; in addition, in the field of high-strength thinning, the forming of many formed parts is relatively complicated, and some require secondary forming or pickling after forming, while The high-strength thin materials produced in the early stage of CSP have problems such as secondary molding cracking or pickling cracking, which seriously restricts the development and promotion of such high value-added products in the CSP production line.

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