JPS62161404A - Continuous hot rolling method - Google Patents

Abstract

PURPOSE:To improve joining strength and rolling efficiency by cutting a preceding material and succeeding material and joining these materials by welding on the inlet side of a finishing mill, providing a looper between a joining machine and the finishing mill and forming the hot material to an S-shaped looper. CONSTITUTION:The rotary type S-shaped looper 5 is constituted of a pair of discs 51, plural pieces of guide rollers 52, and respectively a pair of pushing rollers 53 and pinch rollers 54. A rough rolling material 10 passes a joining machine 3 and the looper 5 and is guided to the finishing mill. The pinch rollers 54 pinch the material 10a and while the material is pushed and curved by the pushing rollers 53, the looper 5 is rotated. The rear end of the preceding material and the front end of the succeeding material are cut, joined and welded and the preceding material of the looper is pair off when the material is looped. The time for joining by welding is reduced and the joining strength is improved. Since the quick passing is possible, the rolling efficiency as a while is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is a continuous hot rolling method in which hot-rolled material rolled from a slab or hot cast material made of thin slabs are joined together and finish rolled continuously. The present invention relates to an inter-rolling method.

(b) Prior art In recent years, continuous hot rolling has been proposed to improve threadability, reduce scrap loss, and improve work efficiency. In this continuous hot rolling, the trailing end of the preceding rolled material and the leading end of the succeeding rolling material are joined by welding or the like in front of a finishing rolling mill, and finishing rolling is performed continuously.

For example, JP-A-58-112601 proposes a rolling line in which a coil box, a stationary welding machine, and a sheet bar storage device are arranged between a rough rolling mill and a finishing rolling mill. JP-A-597209405 proposes a hot rolling line in which a spiral looper is arranged after a fixed welding machine.

However, when welding bars with a thickness of 20 mm or more,
Due to lack of welding capacity, it is difficult to weld the entire cross section in a short time. Therefore, Japanese Patent Application Laid-Open No. 60-223657 proposes a method in which a plurality of welding torches are arranged in the width direction of the bar to perform downward arc bath welding. However, butt welding requires difficult positioning, which takes a long time and is not practical.

In the Senzimya type or Kent type spiral looper proposed in Japanese Patent Application Laid-Open No. 59-209405,
Like other parts, the joint part is bent and unbended within the looper, so there is a risk of the joint part breaking.

In conventional joining methods, the ends of the leading and trailing rolled materials are cut separately and then the ends are joined together. This method is time-consuming and difficult to join the ends smoothly. Therefore, in order to improve this method, a method was developed in which the joined ends are overlapped and cut.

The joining method involves overlapping the rear end of the preceding rolled material and the leading end of the following rolling material, and punching out a jigsaw shape (hereinafter referred to as jigsaw shape) in which the opening width at the end is narrower than the inner width. was. In this method, burrs at the cutting tips occur in opposite directions.

Therefore, after cutting, when the leading and trailing ends of the gauging rolled material are overlapped complementary to each other and fitted together while being pressed, the presence of opposing burrs prevents smooth fitting, resulting in improved rolling efficiency. could not.

Furthermore, Japanese Patent Application No. 59-225487 (
Japanese Unexamined Patent Application Publication No. 1988-61 discloses a method in which the leading and trailing ends of a rolled material are overlapped vertically at intervals and sequentially cut and fitted. This method does not cause burrs on the cut ends, so the ends can be fitted smoothly. However, this method tends to have problems with eliminating end crops and does not allow for adjustment of the interference of the fit.

Therefore, in order to solve this drawback, the present applicant has filed Japanese Patent Application No. 59-260543 (Japanese Unexamined Patent Publication No. 1988-61).
[In a continuous hot rolling line in which finish rolling is performed continuously by joining the rear end of the preceding rolled material after rough rolling and the leading end of the trailing rolled material after rough rolling, the upper and A path for guiding rolled material that moves separately on the lower side is provided, an upper and lower cutter unit consisting of a pair of upper and lower blades is provided in each path, and the upper and lower blades are connected to an opening at the end. The width is narrower than the width of the inner part, and the shape is formed so as to complement each other. cutting at the same timing by the units, and simultaneously moving the cutting leading ends in the direction of engagement with each other and moving the respective passages so as to coincide with the lines, by the upper and lower cutter units; A method for joining rolled materials, which comprises fitting the cut ends so as to complement each other, and welding the side edges of the fitting parts. ” was proposed.

This joining method prevents burrs from appearing at the leading and trailing ends of the rolled material during cutting, easily and reliably eliminates end crops, allows the fitting interference to be arbitrarily selected, and It is extremely effective in performing complementary fitting without any trouble, reliably, and quickly.

(c) Problems to be Solved by the Invention The problems to be solved by the present invention are to effectively utilize the above-described joining method to shorten the joining time of rolled materials, ensure joint strength, and improve the loopability of the joint. The objective is to improve the efficiency of hot rolling by ensuring sheet threadability and preventing breakage.

B) Means for solving the problem The continuous hot rolling method of the present invention unwinds the hot rolled material rolled from the slab or the hot cast material made of thin slab from the coil box and guides it to the finishing rolling mill. cutting the trailing end of the leading material and the leading end of the trailing material into a jigsaw shape using a joining machine on the entry side of the finishing rolling machine and joining them together by fitting and welding; The above problem is solved by forming the hot material into a deformable S-shaped loop by means of a rotary S-shaped looper between the finishing mill and the finishing mill.

The method of the present invention can also solve the above-mentioned problems by cutting the side edge of the joint portion of the rolled material with a side shear between the joining machine and the looper or between the looper and the finishing rolling mill.

(E) Example An example of the method of the present invention will be described below. 1st
The figure shows an example of application to a hot rolling line equipped with a rough rolling mill. First, the configuration of the entire rolling line will be explained. A rough rolled material 10α that has been rough rolled by the rough rolling mill 1 is once wound up into a coil box 2. Next, the rough rolled material 10α
is unwound from the coil box 2 and guided to the finishing mill 6 via the splicing machine 31 and the rotary S-shaped looper 5.

Finish-rolled material 106 that has been finish-rolled by the finish-rolling mill 6
is cut and separated at the joint of the rolled material 1 (l) by the running cutter 7, and then wound around the down coil 28.

As the joining machine 3, the above-mentioned patent application No. 59-260543 is used.
It may be an apparatus for carrying out the method disclosed in the above publication.

This device includes a mechanism that cuts the ends of the leading rolled material and the trailing rolled material almost simultaneously into a jigsaw shape, a mechanism that fits the leading and trailing ends of the jigsaw shapes, and a fitting that includes at least the side edges of the fitting part. A mechanism for welding a part of the joint (for example, arc welding) is provided. By combining jigsaw joints and welded joints, in addition to improving the joint strength of the joint, alignment for welding is extremely easy, shortening the joining time, and improving the reliability of the welded joint. do.

An example of the rotary S-shaped looper 5 will be described with reference to FIGS. 3 and 4. The looper 5 has a plurality of guide rollers 52 rotatably attached in the circumferential direction of a pair of discs 51 arranged in parallel at a constant interval, and a pair of push rollers in the diametrical direction of the discs 51. 253 is installed rotatably,
A pair of pinch rows 254 are rotated at the center of the disc 51.
It can be installed so that it can be opened and closed. The guide roll and pinch roll can also be rotationally driven as required.

A support shaft 55 is rotatably supported by a column 56 at the center of the disk 51, and the disk 51 is driven to rotate in both directions by a motor 57.

The pinch roller 54 is operated by a hydraulic cylinder 58.
It is opened and closed.

The operation of the looper 5 will be explained with reference to FIG.

First, the rough rolled material 10α passes through the joining machine 3 and the looper 5 and is guided to the finishing rolling mill 6 (A).

A loop is then formed in preparation for static bonding.

That is, the pinch rolls 54 close to pinch the rough rolled material 10α, and then the push rolls 53 push and curve the rough rolled material 10CL while driving the disk and rotating the looper clockwise. At this time.

By controlling the traveling speed of the rough-rolled material entering the looper (looper entry speed) to be greater than the speed at which it is rolled out to the finishing rolling mill (looper exit speed), the rough-rolled material is wound around the guide rollers and formed into a loop. (B) Basically, from the viewpoint of preventing the occurrence of flaws on the plate surface during loop formation, it is desirable that the loop be wound one layer, and the diameter of the loop is determined based on the required amount of plate accumulation.

During joining, as shown in C, the trailing end of the leading material and the leading end of the trailing material are thrown into the joining machine and cut.

Connection is performed by fitting and welding. At this time, by rotating the looper counterclockwise, the preceding material accumulated in the looper is discharged to the finishing mill and rolling is performed, so that joining can be performed in a stationary state. The joining is completed,
The trailing material starts running while connected to the leading material, but returns to the state of %A when the joined material enters the roots. Therefore, the joint can be passed through the looper without being bent.

Furthermore, since the leading and trailing ends of the rough rolled material can also be threaded in the state A, no trouble occurs during threading.

When welding the side edges of the fitting part, welding tends to drop off at the side edges, making it impossible to obtain a sufficient welding depth at the side edges. If even more severe rolling conditions are adopted, cracks on the side edges of the joint may develop during finish rolling, which may impede rolling. Therefore, as a countermeasure against this problem, as shown in FIG. 2, a running side shear 41 is disposed between the finishing mill 6 and the joining machine 3 to cut the end of the joining part. In the illustrated example, the side shear 4 is placed between the welding machine 3 and the roots ξ5, but
It may be arranged between the looper 5 and the finishing mill 6.

It is also possible to utilize the loop/ξ5 to arrange a stationary side shear (not shown) between the splicer 3 and the looper 5. By cutting and removing the edge of the joint where the strength of the welded joint is insufficient, a new section with sufficient weld depth becomes the side edge of the joint, increasing the strength of the edge of the joint. , the problem of side edge cracking is solved.

As an example of side shear cutting, FIG. 5 shows the state of the joint after side shear cutting. By cutting and removing part 11 of the side edge weld, it is possible to obtain a joint strength equivalent to that of other welds also at the end of the joint.

(f) Effects According to the method of the present invention, the conventional 1 to 2 minutes required for joining hot materials can be shortened to 10 to 30 seconds, and the amount of accumulated hot materials can be reduced by shortening the joining time. This allows the looper to be made smaller, and the joint strength can be greatly improved by combining the joints.The leading and trailing ends of the hot material and the joint can be threaded without being bent inside the looper, making it possible to pass through the looper. Plate troubles are reduced and overall rolling efficiency is improved.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of equipment for carrying out the continuous hot rolling method of the present invention. FIG. 2 is a schematic partial diagram showing an example of modification of the equipment shown in FIG. 1. FIG. 3 is an explanatory diagram of the operation of the rotary S-shaped roots ξ. Figure 4 is a front view of the looper. FIG. 5 is a plan view of the joint of rolled materials. 1: Rough rolling mill 2: Coil box 3: Joining machine 4: Side shear 5: Rotating S-shaped 6:
Finish rolling mill 7: Inter-travel cutting machine 8: Down coin 10α: Rough rolled material 10h: Finish rolled material 51: Circular plate
52 Guide roller 53: Push-in row 2 54: Pinch roller 55: Support shaft 56: Support column 57: Motor patent applicant ~ 6 Sumitomo Metal Industries, Ltd. (5 others)

Claims (2)

[Claims] (1) Uncoiling the hot-rolled material rolled from the slab or the hot-cast material made of thin slab from the coil box and guiding it to the finishing mill for finish rolling, and joining at the entry side of the finishing mill. The rear end of the preceding material and the leading end of the succeeding material are cut into a jigsaw shape by a machine, and they are fitted and welded to each other, and a rotary S-shaped A continuous hot rolling method comprising forming hot material into a deformable S-shaped loop using a looper. (2) The hot-rolled material rolled from the slab or the hot-cast material made of thin slab from the coil box is uncoiled and guided to a finishing mill for finishing rolling, and a joining machine is installed on the entry side of the finishing rolling mill. cutting the rear end of the preceding material and the leading end of the succeeding material into a jigsaw shape and fitting and welding them together; and a rotary S-shaped looper between the welding machine and the finishing rolling mill. forming the hot material into a deformable S-shaped loop by means of a side shear between the joining machine and the looper or between the looper and the finishing mill; A continuous hot rolling method consisting of cutting.