JPS60184408A - Continuous hot rolling installation of steel strip - Google Patents

Abstract

PURPOSE:To overlap materials smoothly and rapidly by installing a crank mill between the final stand of a roughing mill and a finishing mill and overlapping the end parts of preceding and succeeding materials for connecting them to each other and rolling them at the same time. CONSTITUTION:In a state where the front part of a preceding material S2 is bitten by a finishing mill 2, and the top of a succeeding material S1 is delivered from a roughing mill 1; a detector 3 detects the passage of the top of material S1, and transmits its signal to a control part 9. Measuring rolls 4 output a detecting speed (v1) to the part 9, which calculates the time required for the top to arrive at an overlapping position. A speed (v2) is also inputted to the part 9 at the same time to calculate a feeding speed (v1') accelerated to overlap the end parts of both materials just before a crank mill 7, and the control 9 outputs a command to pinch rolls 5. On the other hand, the top of material S1 is subjected to rolling reduction by an overlapping roll 6, to which a prescribed overlapping quantity is commanded, and is formed into an overlapping part to catch up with the material S2 in the vicinity of the inlet side of mill 7 so as to be in a mutually overlapping state. The timing when the overlapped part passes the mill 7 is caught by the control part 9, which outputs a command to pressure weld the overlapped part and simultaneously roll it by the mill 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to continuous hot rolling equipment for continuously performing hot rolling.

(B) Prior Art In conventional hot rolling, heated slabs are fed one by one to a rolling line, and each slab is subjected to intermittent rolling in a rough rolling mill and a finishing mill.

In this method, when the rolled material passes through the rolling mill.

The leading edge of the material bumps into guides or rolls, and when the trailing edge passes through the rolling mill, the shape of the trailing edge and rolling conditions can cause constriction, which often causes problems such as damage to the rolls. In order to avoid such troubles, it is necessary to take some measures such as lowering the rolling speed, i! Ta.

Once a problem occurs, the downtime of the line increases, leading to an increase in roll consumption.

Compared to the center, the front and rear ends of a rolled material are more prone to temperature drop and thickness deviation due to imbalance in rolling speed, and the center of the 9-width protrudes in the rolling direction and becomes narrower, making it difficult to maintain a predetermined sheet width. It was not obtained and was discarded. In addition, the width of the tip of the rolled material becomes narrow immediately after the finishing work roll is bitten and due to the sudden rise in tension during winding of the down coiler, resulting in a failure to obtain a predetermined width.

Therefore, in recent years, as a method to solve this problem, the trailing end of the preceding rolled material and the leading end of the following rolling material are overlapped on the exit side of the rough rolling mill, and the side surfaces are temporarily welded. A method has been proposed in which rolled materials are joined together and continuously rolled. However, in this blade part, the joint part of the rolled material is thicker than other parts, and rapid load fluctuations are applied to the secondary finishing mill in the upper and lower parts.

Variations occur in plate thickness. The soil and tack bonding had the disadvantage that the bonding strength of the parts was weak, leading to frequent rolling troubles.

(c) Object of the Invention The object of the present invention is to provide a continuous heating system capable of improving rolling efficiency by smoothly and quickly joining the rear end of the preceding rolled material and the leading end of the trailing rolled material. Our objective is to provide rolling equipment.

B) Structure of the Invention The rolling equipment of the present invention incorporates a crank mill between a rough rolling mill and a finishing mill on a rolling line, and joins the ends of a preceding material and a succeeding material to each other. In this case, the crimping connection and rolling are performed at the same time, so that the bond can be quickly bonded with 9 strength and 5 uniform thickness.

The equipment configuration of the present invention will be specifically explained with reference to FIG.

The apparatus of the present invention is installed along the rolling line between the final stand of the rough rolling mill 1 and the first stand of the finishing rolling mill 2, and includes as a main part a control device that operates the apparatus in a coordinated manner. .

First, the material detector 3 is installed at the most flow-stop position on the exit side of the rough rolling mill to detect the passage of the tip of the rolled material and send a detection signal to the control section 9. On the downstream side adjacent to the material detector 3, a first measuring roll (hereinafter referred to as MR) 4 for detecting the feed rate of the material is provided. This first MR4 mainly detects the speed (υ, ) of the trailing material S1, and depending on the contact point of the trailing material S1 and the detection speed (υ1), the process up to the nose-up roll 6, which will be described later, is performed. The purpose is to measure the longevity of the person.

On the downstream side adjacent to the first MR4, there is a pinch roll (
Hereinafter referred to as PR. ) 5 will be provided. This PR5 is a roll that changes the feeding speed of the trailing material S, according to each work process, and the trailing material S detected by the first MR4,
(7) [(IJI ) and the feed rate (υ ,') are commanded from the control unit 9, thereby increasing the feeding speed of the trailing material S,. Then, at a predetermined joining position, the rear end (hereinafter referred to as bottom) of the preceding member S2 is attached to the tip end (hereinafter referred to as top) of the trailing member S1.

) can catch up with each other and overlap each other.

A nose raising roll (hereinafter referred to as HR) 6 is provided on the downstream side of PR, 5. HR6 uses upper and lower rolls with different roll diameters (・, the top of the material is raised upward by rolling down, the upper roll has a large diameter, and the upper and lower rolls are rolled with a speed difference.

This speed difference includes zero and is the amount of nose raising.

That is, it is determined according to the nose height h) and the nose height 12), and the predetermined conditions are calculated by the microcomputer 91 of the control section 9 and commanded by the controller 92.

A crank mill (hereinafter referred to as
It's called CM. ) will be established. 0M7 performs strong crimping and rolling at the same time, and is operated in synchronization with the timing when the bottom of the preceding material S2 and the top of the succeeding material S1 are overlapped and introduced, and the ends of the materials are The material is crimped and bonded reliably and quickly, and rolled to the same thickness as the other parts of the material. The timing of pressing down and the pushing force of the crimping reservoir are commanded from the control m9.

Each of the rolls constituting the equipment of the present invention is equipped with a motor for rotating the roll (hereinafter, a subscript α is added) and a motor for rolling down the roll (hereinafter, a subscript is added). All the motors other than the roll rotation motor 4α of the first MB2 and the roll rotation motor 8α of the second MB2 are controlled based on commands from the control unit 9 in accordance with the work process,
Predetermined operations are performed in conjunction.

Next, the operation of the nine devices will be explained. As shown in FIG. 1, the front part of the preceding material S has already been rolled through the finishing mill 21. /?
- In a state where the top of the trailing material S1 has started to come out of the rough rolling mill 1, the material detector 3 first detects the passage of the top of the trailing material S, and sends a signal to the controller 91. Here, the controller 91 commands the 10th MR4 the rough thickness obtained in advance from a host computer (not shown), and the first MB2 sets an i-le gap commensurate with the commanded rough thickness. and wait for it to reach the trailing material.

The 10th MJ starts measurement when the trailing material S1 comes into contact with it, inputs the detected speed (υ,) to the microcomputer 91, and calculates the time taken for the top to reach the nose-up position. Operate the conbeater 91vc. At the same time, the feed rate (υ2) of the preceding material S2 is also fed into the microcomputer 91 from the second MB2.

Based on the speed of the leading material (υ2) and the speed of the trailing material (υ1), the microcomputer 91 calculates an accelerated feed rate (υ, l) for the ends of both materials to overlap just before CM7.
is calculated and commanded to PR5 via the controller 92. on the other hand,
Separately, the controller 92 commands the HR6 to raise the nose by a predetermined amount (h, /2), and performs a lowering operation as the top of the trailing material S approaches to raise the nose by a predetermined amount. Shape the raised part.

The trailing material S, whose top is turned up, is transported at a feed rate (υ11) accelerated by PR5.

(9) Near the entry side of 0M70, the material catches up with the preceding material and the ends thereof are overlapped with each other. At this point, PR5 is commanded the original feed rate that has been decelerated by the acceleration, ie, the feed rate (υ21) that is synchronized with the preceding material 52vc.

The overlapping art materials are introduced into the 0M7 as if they were a single body. On the other hand, at 0M7, a rolling command is issued from the control unit 9 at the timing when the nine overlapped portions pass through 0M7, and the overlapped portions are crimped using a preset pushing force and rolled at the same time.

In the pressure welding process of 0M7, if this is just press pressure bonding, there is a risk that the pressure welded part will break in the downstream rolling process. Therefore.

In the present invention, the pressure contact surface is descaled immediately before pressure contact, and a non-oxidizing atmosphere is maintained after descaling until pressure contact is performed. As shown in FIG. 2, a method for satisfying this condition is to cover the steps from HR6 to 0M7 from the outside in a sealed chamber 10, and then inject N2 into the chamber 10. is supplied to form a non-oxidizing atmosphere, and at the same time, the ends of the materials immediately before being overlapped are descaled using a hot scarf or a wire brush 11. It's Kade.

As another means of descaling, a fluoride such as ammonium borofluoride can be sprayed onto the pressure contact surface to obtain a localized completely non-oxidized state.

(E) Example 2 extracted from the heating furnace with a thickness of 27 m x width of 1600 mm
This slab (1250°C) is rolled to a thickness of 30 mm by a rough rolling mill consisting of 6 stands on a normal rolling line.
After rolling down to a height of 30 mm, a light reduction of 1 mm was applied using an HR6 having an upper roll diameter of 50 mm (h++ m + a lower roll diameter of 300 mm) to obtain a straight-up amount h = 30 mm.

Thereafter, the pressure contact surface was descaled over the entire width of 50 mm using a wire brush that could be fed in synchronization with the feed material and that could be moved freely. At this time, the temperature of each rough bar is 950-10
It was 00°C. At this time, the preceding material is 0.75m/
Since the material was being sent to the finishing mill in sec, the speed of PR5 was controlled to catch up with the top of the trailing material, resulting in one overlap of 30 yn.
The superimposition was completed at the position closest to CM7 while maintaining m.

After that, PR, 5 (1
1) Synchronize the feeding speed of the art materials by controlling
The material was transferred into a closed chamber 10 in a non-oxidizing atmosphere in which N2 (2'/mrn2) was press-fitted, and the pressure welded part was made 30mm thick by CM7 between runs. CM7 at this time
Pressure h 22kgAm2. The load was 1100 tons.

When this press-welded material was conventionally rolled in the finish rolling process, it was possible to perform continuous rolling without causing breakage, and the hot rolling process was completed to obtain a copper strip with a thickness of 2 mm and a width of 1600 mm. .

(f) Effects Although the equipment of the present invention is relatively compact, it is capable of powerfully and quickly joining hot-rolled steel strips.
Moreover, there is no need to stop the line for joining.
Extremely efficient.

In addition, since the joint part does not become thicker than other parts, load fluctuations are not applied during the finish rolling process, and rolling troubles and variations in plate thickness do not occur.

[Brief explanation of drawings]

(12) FIG. 1 is an explanatory diagram schematically showing the overall configuration of a continuous hot rolling facility according to the present invention. FIG. 2 is a partial view of FIG. 1 showing the structure of a reservoir for forming a non-oxidizing atmosphere. 1: Rough rolling mill 2: Finish rolling mill 3: Material detector 4.8: Measuring roll (MR) 5: Pinch roll 6: Directly above k-zb (HR) 7: Crank mill (CM) 9: Control part 10: Chamber S, : Trailing rolled material S2: Preceding rolled material Patent applicant Sumitomo Metal Industries, Ltd. (13) A

Claims (2)

[Claims] (1) A material detector that is installed between the final stand of the rough rolling mill and the finishing mill to join the bottom of the preceding rolled material and the top of the succeeding rolled material, and detects the top of the succeeding material. The first step detects the moving speed (υ1) of the trailing material and measures the time when the top of the trailing material reaches a predetermined nose-up position.
a second measuring roll that detects the feed rate (-) of the preceding material; and a second measuring roll that detects the feed rate (-) of the preceding material, and a measuring roll that is arranged downstream of the first measuring roll and detects the feeding speed (-) of the succeeding material at a predetermined joining position. A pinch roll keeps the trailing material in an increased speed state (υ, 1) so that the top overlaps the bottom of the leading material, and a pinch roll is placed at a nose-up position on the downstream side of the pinch roll and presses down the top of the trailing material. A nose raising roll for forming a nose raising margin of a predetermined length; and a crank mill, which is placed at a joining position on the downstream side of the nose raising roll and crimping and rolling the overlapping portion of the preceding material and the subsequent bamboo material with a pushing force. , commands for the acceleration speed (U+') during overlapping and reference speed (02') after overlapping for the pinch rolls, commands for the rolling amount for the nose-up roll, and commands for the rolling down timing and pushing force for the crank mill. Continuous hot rolling equipment for copper strips, consisting of a control section that generates heat. (2) A material detector that is installed between the final stand of the rough rolling mill and the finishing mill to join the bottom of the preceding rolled material and the top of the succeeding rolled material, and detects the top of the succeeding material. The first step detects the moving speed (υ1) of the trailing material and measures the time when the top of the trailing material reaches a predetermined nose-up position.
0 Measuring roll and feed speed of preceding material (υ2)
a second measuring roll that detects the following material; A pinch roll that maintains VC in an increased speed state (υl'), a nose raising roll that is arranged at a nose raising position on the downstream side of the pinch roll and presses down the top of the trailing material to form a nose raising margin of a predetermined length; A crank mill is arranged at the joining position downstream of the raising roll and press-rolls the overlapping part of the leading material and the following material with pushing force, and the acceleration speed (01') at the time of overlapping with respect to the pinch roll and A control unit that coordinately issues a command for the reference speed (02') after superposition, a command for the amount of rolling to the nose-up roll, a command for rolling down timing and pushing force to the crank mill, and crimping of the front and rear art materials at the position just before joining. Continuous hot rolling equipment for copper strips, which consists of a device that descales the surface and maintains a non-oxidizing atmosphere until it is crimped.