JPS61206507A - Installation for manufacturing cold-rolled steel sheet - Google Patents

Abstract

PURPOSE:To reduce the initial cost of a manufacturing installation of cold-rolled steel sheet by arranging an electric furnace, a twin-roll type or an endless-track type continuous sheet-casting machine, a light descaling device and a cold rolling mill on an on-line. CONSTITUTION:A high-quality molten steel 2 produced in an electric furnace 1 by using as raw materials, scraps or reduced iron, is transferred from a ladle 3 to a tundish 4, and is poured into a continuous casting machine 5. The cast strip 7 is cooled by a cooling device 6 and lightly descaled by a light descaling device 8, and then is passed through a cold rolling mill 9. The rolled strip 7 of prescribed thickness is taken up by a winder 11 through a shear 10. In this way, a cold-rolled steel sheet manufacturing installation, low in initial cost and running cost, is obtained.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to cold rolled steel plate manufacturing equipment.

[Conventional technology] The best method for producing cold-rolled steel sheets, especially thin steel sheets.

The method that is also common and still practiced is that molten steel produced by the blast furnace-converter method is cast into a continuous slab casting machine, and the cast thick slab is passed through a separate hot rolling line 10 times or more. It is rolled into a thin comb (usually in 4 stands of rough rolling mill and 117 stands of finish rolling mill) and wound up in a winding machine to form a hot coil, after which it is descaled and passed through a cold rolling line to form a cold rolled material. This is the final product. However, this method requires many rolling processes and a huge amount of rolling equipment, so it is difficult to set up a large amount of rolling equipment.
J The cost is high, and since it is necessary to heat the slab and control it at a constant temperature, it requires a large amount of heating energy and it is necessary to roll from a thick slab to a thin hot coil and then to an inexpensive cold rolled coil. Because of this, the rolling energy of the crowd is required.

Against this background, in recent years, continuous thin plate casting machines such as twin roll type and endless track type (block type, belt type) that can directly cast thin metal sheets from molten steel have been developed. A continuous manufacturing facility for thin sheets has been proposed, which rolls and finishes sheets to a predetermined thickness online.

[Problems to be Solved by the Invention] However, in such continuous thin plate production equipment, although rolling energy and heating energy can be reduced compared to when using the above-mentioned continuous slab casting machine, molten steel is produced in a blast furnace.
Because it is manufactured using the converter method, the initial cost of the furnace equipment accounts for a large proportion of the product cost, making it unsuitable for manufacturing parts that do not require relatively high V3 quality, such as general structural forestry and construction materials. Met.

Therefore, at present, there are only a few examples of continuous thin plate manufacturing equipment being implemented.

[Means for Solving the Problems] The present invention was made in view of the above-mentioned circumstances, and includes an electric furnace, a twin roll type or endless track type thin plate continuous casting machine, a cooling device, an editorial scale device, and the like. , and a cold rolling mill are arranged online.

[Function] Therefore, a thin plate is cast from molten steel whose composition has been adjusted using scrap or reduced iron as the main raw material, and after being descaled, it is finish rolled in a cold rolling mill.

[Example] In Fig. 1, 1 is an electric furnace, and the electric furnace 1 melts scrap or reduced iron as the main raw material and adjusts the components (additives, vacuum degassing, etc.) to melt [12]. It is manufactured. 3 is a ladle for transporting the molten steel 2 produced in the electric furnace 1; 4 is a tundish that supplies the molten steel 2 received from the ladle 3 to the twin-roll continuous casting machine 5; and 6 is a strip 7 cast by the continuous casting machine 5. 8 is a scale device consisting of a wet blasting device for removing light scale on the surface of the strip 1; 9 is a scale device for removing the scale from the strip 7; A cold rolling machine for finishing to a predetermined thickness, 10 a shear, and 11 a winding machine are arranged in an online configuration.

In such a configuration, molten steel 2 is produced in an electric furnace 1 using scrap or reduced iron as the main raw material, but as refining technology has improved recently, it has been made considerably more expensive by performing vacuum degassing and adding additives. A quality solution I12 is obtained. This molten steel 2 is transported by a ladle 3 and transferred to a tundish 4, and is supplied (poured) from the tundish 4 to a continuous casting machine 5 through an immersion nozzle. The strip 7 cast by the continuous casting I15 is cooled by the cooling device 8 to a room temperature state with minimal scale. The cooled strip 7 is then lightly scaled by an editorial scale device 8 and then cold rolled to the desired thickness by a cold rolling FM 9. The cold-rolled strip 7 is cut by a shear 10 and wound into a coil by a winder 11.

As described above, in the present invention, the molten steel 2 is manufactured using the small-scale electric furnace 1 instead of the blast furnace-converter method that requires large-scale equipment, so the strip 7 cast from the continuous casting M*5 is Although its uses are limited, it achieves a much lower cost than conventional methods and costs 1q. In addition, since the strip 7 cast by the continuous casting machine 5 is already a thin steel plate, the number of stands in the cold rolling mill 9 can be significantly reduced compared to the conventional manufacturing method using continuous slab vI21Jl.
Thin steel sheets can be manufactured efficiently and continuously. Therefore, the running cost of the entire equipment is also low.

FIG. 2 shows another embodiment of the present invention, in which an endless track type (block type in the figure) continuous casting machine 5' is used instead of the twin roll type continuous casting 115 in the illustrated embodiment, and the continuous casting machine A shear 10 is disposed downstream of the shear t-10, and one or more hot reverse rolling mills 13 with hot winding machines 12 at the front and rear are disposed downstream of the shear t-10. A cooling device 6' is arranged downstream of the rolling mill 13 to minimize scale generation.

In FIG. 2, the same symbols as in FIG. 1 indicate the same parts.

In such a system, the strip 7 cast by the track continuous caster 5' is thicker than the strip 7 cast by the twin roll continuous caster 5, so it is rolled by the hot reverse rolling mill 13 before cold rolling. Hot rolled. After hot rolling, the stop 7 is cooled by a cooling device 6' and then transferred to a cold rolling mill 9 via an editorial scale device 8 in the same manner as in the previous embodiment.
Cold rolling is carried out at.

By the way, the energy consumption rate per ton of refined steel until molten steel is obtained is 3.8 million) (cal) in the case of the blast furnace-converter method.
/lon, and in the case of electric furnace method, 1.4 million Kcal
/lon.

It should be noted that the present invention is not limited only to the above-mentioned embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effect of the invention 1 As explained above, according to the present invention, molten steel is produced using scrap or reduced iron as a main raw material by an electric furnace method instead of the conventional blast furnace-converter method, and this molten steel is converted into an electric furnace. Casting is performed using a continuous casting machine located online, and then finished as a cold-rolled steel sheet using a cold rolling mill, making it possible to downsize the entire equipment and reduce initial and running costs. It is possible to achieve excellent effects such as being able to reduce product costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a cold-rolled steel plate manufacturing facility of the present invention, and FIG. 2 is an explanatory diagram of another embodiment of the present invention. 1 is an electric furnace, 5 is a twin-roll continuous casting machine, 5' is an endless track continuous casting machine, 8 is an I11 descaling device, 9 is a cold rolling mill, and 13 is a hot reverse rolling mill. Patent application Hitoshi Kawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Scope of Claims] 1) An electric furnace that produces molten steel using scrap or reduced iron as a main raw material, a twin-roll continuous casting machine that casts a strip using the molten steel produced in the electric furnace, and minimizes scale generation. Cold-rolled steel sheet production equipment characterized by an online arrangement of a cooling device, a light descaling device for removing light scale, and a cold rolling mill for finishing the strip to a predetermined thickness after removing the scale. 2) An electric furnace that produces molten steel using scrap or reduced iron as the main raw material, an endless track type continuous casting machine that casts strips using the molten steel made in the electric furnace, and a continuous track type casting machine that casts strips by the endless track type continuous casting machine. A hot reverse rolling mill that performs hot rolling, a cooling device that minimizes scale generation, and a light descaling device that removes light scale.
Cold-rolled steel plate manufacturing equipment characterized by an online arrangement of a cold rolling mill that finishes strips after removing scale to a predetermined thickness.