JPS6024201A - Continuous hot rolling method - Google Patents

Abstract

PURPOSE:To improve the rolling efficiency and the quality and yield of a product in continuous hot rolling by abutting the rear end of a preceding rolling material to the front end of a succeeding rolling material during rolling and welding both ends together by a thermit welding device moving synchronously with the materials. CONSTITUTION:On a table 7 installed between the roughing mill 1 and the finishing mill 2 of a continuous hot rolling equipment; the rear end of a preceding rolling material 5 and the front end of a succeeding rolling material 6 are formed into flat end-surfaces respectively by cutting them by a flying crop shear 3, and are abutted to each other with a given joining gap between them. The rolling speeds of the mills 1, 2 are synchronized with each other to maintain said gap, and a hopper 10 for feeding a thermit mixture is moved in the material-width direction on a carriage 9 by driving a motor M2 while moving, synchronously with the materials 5, 6, the carriage 9 on which a thermit welding device 4 is mounted; then the gap is filled with the thermit mixture, and an ignition agent is fed from an ignition agent feeding hopper 24, to ignite by an ignition device 11 successively, thereby joining both materials together by thermit reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous hot rolling method in which the leading and trailing ends of a rolled material are connected and continuously rolled using hot rolling fins.

In the conventional hot rolling method, the heated slabs are fed one by one to the rolling line, and each slab is passed through a rough rolling mill, then through a rolling mill, and then into a rolling mill.
This is intermittent rolling in which 1E rolling is performed in a rolling mill.

In this method, when the rolled material passes through the rolling mill, the leading end of the rolled material may hit the Squeezing occurs, leading to problems such as roll damage. In order to avoid such troubles, it is necessary to take measures such as lowering the rolling speed. Once a toffull occurs, it is necessary to stop the line or change the roll.

Therefore, the downtime of the line increases, leading to an increase in the roll consumption rate.

The front and rear ends of the rolled material are more prone to temperature sieving and thickness deviation due to imbalance in rolling speed than the center, and the center of the width protrudes in the direction of the rolling chisel and becomes narrow, making it difficult to obtain the desired sheet width. It was cut off and discarded. In addition, the width of the tip of the rolled material becomes narrow in some areas immediately after it is bitten by the work roll and due to the rapid tension build-up during the first round of down winding, making it impossible to obtain the desired width. was there.

Therefore, in recent years, as a method to solve this problem, the rear end of the preceding rolled material and the leading end of the following rolled material are overlapped on the entry side of the rough rolling mill, and the side surfaces are tack welded. A method has been proposed in which rolled materials are joined together and rolled continuously. However, in this method, the joint part of the rolled material becomes thicker than other parts, which causes sudden load fluctuations in the rolling mill and causes variations in board thickness. Furthermore, tack bonding has weak bonding strength between parts, leading to frequent rolling troubles.

This invention aims to advantageously solve the above-mentioned problems, and improves rolling efficiency by smoothly and quickly joining the rear end of the preceding rolled material and the leading end of the trailing rolled material. This paper proposes a continuous hot rolling method that can improve product quality and yield.

In the continuous hot rolling method according to the present invention, the rear end of the preceding rolled material and the leading end of the trailing rolled material are butted together with a desired spacing, and a thermite welding device provided along the rolling fins is applied to the rolled material. The feature is that the thermite welding is carried out by moving in sync with the welding process, followed by rolling.

According to this method, the joint part between the preceding rolled material and the subsequent rolled material has the same thickness as the other parts, so there is no sudden load change on the rolling mill, and there is no possibility of sudden load fluctuations caused by the joint part. There is no variation in board thickness.

In addition, since the butt welding is performed using the Chilmitsu I welding method, the bonding force is stronger than that of the conventional lap welding method, and rolling troubles do not occur. Furthermore, since it is a running joining method, rolled materials can be joined without stopping the fins. Therefore, the leading and trailing ends of the rolled material can be joined smoothly and quickly, and rolling efficiency, product quality, and yield can be improved.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, to briefly explain about thermite welding, this welding method was invented as a rail welding method, and its origin is 1! 11 is a method in which a thermite agent mixed with iron oxide powder and aluminum powder is heated to generate heat through a thermite reaction to produce molten iron, and the base materials are bonded using this molten iron. There are two ways to join metal bodies such as rails using thermite welding: the joint gap between the metal bodies is surrounded by a refractory mold, and molten metal produced by thermite reaction is poured into this gap, and thermite agent is poured into the joint gap. Fill it with 8
- There is a method of fusion joining using thermite reaction, which is used depending on the welding base material, welding location, etc.

This invention employs a method of filling the joint gap with a thermite agent and melting and joining by thermite reaction, and rolling the preceding rolled material and the subsequent rolled material after joining them. Shown in Figure 1.

! In Figure 1, (1) is a rough rolling mill, (2) is a finishing rolling mill, (3) is a flying crop shear, (4) is a mobile thermite welding device, (5) is a pre-rolled material, and (6) is a mobile thermite welding device. indicates the subsequent rolled material.

The mobile thermite welding device (4) removes several cheap rollers between the rough rolling mill (1) and the finishing mill (2), and installs a bed plate (7 ), and the preceding rolled material (5) and trailing rolled material (6) are joined on this bed.The structure is shown in enlarged form in Figures 2 and 8. (, said base plate (
7) Side plates (8) surrounding both sides of the joint gap between the leading rolled material and the trailing rolled material are provided on the upper surface in parallel to each other in the direction of the fins, and this side plate (8) and the top surface of the base plate (7) A mixture of iron oxide powder and aluminum powder is fed into the joint gap from the thermite supply hopper 01 installed on the platform (9) that surrounds both sides and bottom of the joint gap and moves along the platform (7). After filling from the upper opening and supplying the igniting agent (e.g. Ba, 0.0) from the igniting agent supply hopper C provided on the same frame, the thermite agent is ignited with the ignition device ff1 (e.g. burner) αη and the thermite agent is pre-rolled. Material (5) and trailing rolled material (6
) are fused and joined together.

The pedestal (9) is mounted on a rail Q, )-1= laid parallel to the rolled material on one side of the pedestal (7), and a reversible motor (M,) (hereinafter referred to as ``pedestal'') is installed at the bottom of the pedestal. It is a self-propelled type that reciprocates using a running motor (referred to as a "travel motor"), and the thermite agent supply hopper 01 is attached to an arm part (toward) that projects horizontally in the line width direction so that it can move freely in the middle direction of the rolled material. It is suspended. As the traverse mechanism of this hopper, a single screw 0→ rotated by a reversible motor (Ml) (hereinafter referred to as "hopper traverse motor") is installed in the arm part (to) of the gantry, and this screw Natsuto screwed into (To)
The support shaft α protruding from the shaft is slidably penetrated into the long hole of the bearing plate αη provided parallel to the screw α→, and the hopper suspension rod (10 is suspended from the end of the support shaft). By driving the hopper running motor (M2), the screw aIO
The nut (to) screwed into the long hole (to) of the bearing plate (0't)
The thermite agent supply hopper α1 moves in the direction of the rolled material l] via the support shaft 0 and the hopper hanging rod a1 that slide inside.

Note that the popper traveling mechanism shown here is just an example, and is not intended to be specific. (a) is the hopper gate opening/closing device. The ignition device (I◇ and the ignition agent supply hopper ■ are connected to the hanging rods a c, !i installed vertically on the arm part 03.
> is suspended at a predetermined height position.

When continuously rolling on a hot rolling line equipped with the above welding equipment, the rear end of the preceding rolled material (5) and the trailing rolled material (6)
After the tip of the material is cut by the flying crop shear (3) to form a flat end surface, when the trailing rolled material (6) is released from the rough rolling mill (1), the conveying roller c1D The rear end of the leading rolled material (5) and the trailing rolled material (6) are controlled by controlling the rotation speed of the finishing mill (2) and the rolling speed of the finishing rolling mill (2).
Butt the tips of the two together with a certain joint gap (a). In addition, when the trailing rolled material is caught in the rough rolling mill (1), the rolling speeds of the rough rolling mill (1) and finishing rolling mill (2) are controlled to reduce the rolling speed of the trailing rolled material (5). part and trailing rolled material (6
) are butted against each other with a certain joint gap (A), and then the rolling speed of the rough rolling mill (1) and finishing rolling mill (2) is made the same (7) to maintain the joint gap. When the joint gap is located directly under the gate of the supply hopper, the gantry (9), which is waiting parallel to the rolled material on one side of the pedestal (7), is moved by the gantry traveling motor (M).
, ) to start moving synchronously with the rolled material. At the same time, the hopper gate opening/closing device (E) is opened to start supplying the thermite agent to the joint gap, and the hopper traverse motor (pigeon) is driven to move the thermite agent to the thermite supply hopper α.
1 is moved toward the middle of the rolled material. Part 1. and the joint gap (
2) When the inside is filled with thermite agent, the hopper gate is closed by the gate opening/closing device (E), and at the same time, the igniter ■ is supplied from the igniter supply hopper (Incorporated), and then the igniter θ→ is used to fill the joint gap with the thermite agent. The dermite agent is ignited, and the preceding rolled material (5) and the succeeding rolled material (6) are melted and joined by a thermite reaction. In this way, the pre-rolled material (
6) and the subsequent rolled material (6) are completed. At this time, 7
- By controlling the rolling speed of the finishing rolling mill (2) and the conveying speed of the conveying roller 6D in front of the finishing rolling mill, or the rolling speed of the roughing mill (1), the rear end of the preceding rolled material and the trailing rolling By strongly pressing the tips of the materials, impurities generated at the joint due to thermite reaction can be removed, and the bond can be made as a pure tissue. As shown in Fig. 4, the joint portion that has been joined has a slightly raised upper surface bead portion, so that no large load fluctuation occurs in the next step of finish rolling. Note that, if necessary, a scraper or the like may be provided on the frame (9) of the thermite welding device (4) to scrape off the bead portion.

In addition, as another embodiment of the present invention, instead of thermite welding using the above-mentioned bed plate method, a mold (a) consisting of a bottom plate (7) and side plates (8) as shown in FIG. 5 is used. Surrounding the joint gap between the rolled material (5) and the trailing rolled material (6),
A method of performing thermite welding may also be used. In this case, the mold (c) may be mounted on the self-propelled pedestal (9) using a cylinder or the like so that it can move up and down and back and forth.

8 - In addition, as shown in the vEG diagram, it is also possible to perform dermite welding without a bottom plate by bevelling the rear end of the leading rolled material (5) and the tip of the trailing rolled trA (6). Furthermore, as shown in Fig. 7, spacers (b) and (c) for reliably holding the joint gap are integrally provided on the bottom plate (7) or side plate (8) of the mold (to). You can also do it.

Next, an example will be described in which a thermite welding apparatus shown in FIGS. 1 to 8 was incorporated between a rough rolling mill and a finishing mill in a normal continuous hot rolling line to carry out continuous rolling.

〔Example〕

Two wooden slabs (thickness 270fl x width 1600ff) extracted from the heating furnace are rolled into a rolled material with a thickness of 80mm x width of 160011mm by a rough rolling mill consisting of 6 nuts with normal continuous hot rolling fins, and then the rolled material is After cutting the rear end of the leading rolled material and the leading end of the trailing rolled material with a crop shear, butt them together with a gap of 20H,
After joining both the rolled materials by thermite welding while moving at a running distance of 60 m/min, finish-1 rolling was performed using a finishing rolling mill consisting of 7 stands. As a result, there was no breakage at the joint during finish rolling, and there was no large load fluctuation.2. It was possible to continuously hot-roll a copper strip with Off thickness x 1601 m width.

In this example, the length of the base plate (7) in the rolling direction is 60001ff, the height of the opening/closing gate of thermite supply hopper 〇〇 is 209 ym from the surface of the rolled material, and the height of the ignition bag WIQl) is 59 rllM. As a thermite agent, wire scale (Fe304) and AI powder (approximately 100
Metsu! /yu), the supply amount of thermite agent is 15.2
It was #1.

As is clear from the examples described above, according to the present invention, it is easy to join rolled materials, and the material yield is improved. Energy savings can be achieved by improving unit consumption and shortening line down time.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an embodiment of the present invention, Fig. 2 is an enlarged rear view taken along the line ■-■ in Fig. 1, Fig. 8 is a plan view of the same 11, and Fig. 4 is a pre-rolled material. FIG. 5 and FIG. 6 are perspective views showing another Tilmitsu F welding method according to the present invention, and FIG. 7 is thermite welding shown in FIG. 5. It is a perspective view showing the types of molds. 1... Rough rolling mill, 2... Finish-L rolling mill, 8... Footing crop ν-year, 4... Mobile chiller)
Welding 1 position, 5... Leading rolled material, 6... Following rolling material,
7... Base plate, 8... Side plate, 9... Frame, 10.
...Dermite agent supply tube 111...Ignition M [1
1, 12...Rail, 1B...Arm part, 14...
・Screw, 15...Nut, 16...Spindle, 1
7... Bearing plate, 18... Long hole, 19... Hopper hanging rod, 20... Hopper gate opening/closing device, 21...
Ignition device hanging rod, 21'...Ignition agent supply hopper hanging rod,
22... Joint gap, 28... Thermite agent, 24...
...Ignition agent supply hopper, 80...Ignition agent, Ml...
・Motor for traveling the gantry, M...Motor for traversing the hopper. Applicant: Sumitomo Metal Industries, Ltd. KUATSUMI ↑ " JP-A BRGO-24201 (5) Figure 4 Figure 5 i ↓ JP-A SHO GO-24201 (6') Figure 7 ((1) (b) , 267'fu P Figure 6 7'-Rikiinka Ichiriki

Claims (1)

[Claims] At the request of the hot rolling line f, the rear end of the preceding rolled material and the leading end of the trailing rolled material are butted together with a desired spacing, and a thermite welding device provided along the rolling fins is attached to the rolled material. Continuous % type % characterized by rolling after moving and thermite welding