Method for producing ultra-thin hot-rolled strip steel

Patent metadata

Field	Value
Publication number	US-2021317543-A1
Application number	US-201917273016-A
Country	US
Kind code	A1
Filing date	Sep 12, 2019
Priority date	Sep 14, 2018
Publication date	Oct 14, 2021
Grant date	—

Abstract

A method for producing ultra-thin hot-rolled strip steel, the method comprising the following process steps: A. a smelting process: feeding scrap steel into an induction electric furnace (1) for smelting so that the scrap steel melts into molten steel; B. a refining process: using a ladle refining furnace (2) and a ladle vacuum degassing furnace (3) to refine the molten steel; C. a continuous casting process: casting the refined molten steel into a cast strip blank that has a thickness of 1.6-2.5 mm by means of a dual-roller thin strip continuous casting system (4); D. a hot rolling process: directly feeding the cast strip blank that was cast in the continuous casting process to a single-stand hot rolling mill (9) for rolling to produce hot-rolled strip steel, the thickness of the hot-rolled strip steel being 0.8-1.5 mm; E. a cooling coiling process: performing atomizing cooling on the hot-rolled strip steel, and coiling after the strip steel temperature is controlled to be 400-750° C. The present method achieves an extremely compact, environmentally-friendly and economical ultra-thin hot-rolled strip steel production process flow, and achieves the environmentally-friendly and economical continuous production of metal plates and strips.

First claim

1 . A method of producing ultra-thin hot-rolled strip steel, comprising the following process steps:
(A). Smelting step: scrap steel is delivered to an induction electric furnace for smelting, so that the scrap steel is melted into molten steel; (B). Refining step: a ladle refining furnace and a ladle vacuum degassing furnace are used to refine the molten steel; (C). Continuous casting step: the refined molten steel is cast through a twin-roll thin strip continuous casting system to form a cast strip blank having a thickness of 1.6-2.5 mm; (D). Hot rolling step: the cast strip blank that has been cast in the continuous casting process is directly delivered to the single-stand hot rolling mill for rolling to form a hot rolled strip, wherein the thickness of the hot rolled strip is 0.8-1.5 mm; (E). Cooling and coiling step: the hot-rolled strip steel is subjected to atomization cooling treatment, and the temperature of the strip steel is controlled at 400-750° C., followed by coiling.

2 . The method of producing ultra-thin hot-rolled strip steel according to claim 1 , wherein in the smelting step, the scrap steel is delivered to the induction electric furnace by a charging vehicle having a preheating function, wherein a preheating temperature is 200-500° C.

3 . The method of producing ultra-thin hot-rolled strip steel according to claim 1 , wherein the twin-roll thin strip continuous casting system has a casting speed of 60-150 m/min.

4 . The method of producing ultra-thin hot-rolled strip steel according to claim 1 , wherein in the hot rolling step, the single-stand hot rolling mill has a total rolling reduction rate of not less than 15%.

5 . The method of producing ultra-thin hot-rolled strip steel according to claim 1 , wherein when the cast strip blank that has been cast in the continuous casting step is delivered to the single-stand hot rolling mill, a protective enclosure is provided around the cast strip blank, and an inert gas is fed into the protective enclosure.

6 . The method of producing ultra-thin hot-rolled strip steel according to claim 1 , wherein in the cooling and coiling step, when the hot-rolled strip steel is subjected to the atomization cooling treatment, the temperature of the hot-rolled strip steel is decreased at a cooling rate of 10 to 80° C./s.

7 . The method of producing ultra-thin hot-rolled strip steel according to claim 6 , wherein the atomization cooling treatment of the hot-rolled strip steel adopts three-stage cooling, wherein cooling capacities of the three-stage cooling are 50-80° C./s, 20-50° C./s and 10-20° C./s in order.

Assignees

• Baoshan Iron & Steel

Inventors

• Fang Yuan
• Wu Jianchun
• Zhang Jian

Classifications

• C21D8/02

  during manufacturing of plates or strips (C21D8/12 takes precedence) · CPC title

• C21D9/52 Primary

  for wires; for strips {; for rods of unlimited length} · CPC title

• B22D11/1206

  for plastic shaping of strands (rolling mills B21B1/46) · CPC title

• C21D9/46

  for sheet metals · CPC title

• B22D11/144

  with a rotating mould · CPC title