JP3471528B2 - Slab cutting method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a slab in a continuous casting process of metal. 2. Description of the Related Art The prior art is disclosed in Japanese Patent Laid-Open No. 6-126.
No. 407, "Method of detecting end face position of slab and confirming cut in continuous caster or the like" is known. In order to increase the efficiency of continuous casting, an operation of changing the casting width during casting is performed in order to continuously produce slabs of different widths. Since the casting width change is performed continuously during casting,
The edges of the cast slab after casting are not parallel to the casting direction.
As shown in FIG. 2, the operation of increasing the width when changing the width from the slab shape is referred to as Y change, and the operation of reducing the width is referred to as reverse Y change. Conventionally, since the end face of the width-changed portion is not parallel to the casting direction, the changed portion is attached to a narrow slab and cut in the width direction, and then cut in accordance with the narrower width (FIG. 3). (The shaded area is cut.) Recently, the width change portion can be rolled as it is due to the improvement of the rolling technology, so that cutting at an arbitrary position is required. [0003] As a method of cutting a continuously cast slab to a predetermined length, a cutting machine equipped with a gas torch moving in synchronization with the slab uses a mixed flame of oxygen and propane gas to cut the slab. It is common to melt from the end face toward the center. [0004] In a cutting method using a gas torch, it is necessary to accurately grasp the end face position of a slab and optimize the cutting start position. The reason is that when cutting starts from the outside of the slab, the flame from the torch cuts the transport roll that extends downward and retreats downward during cutting as much as the slab does not cut, If the cutting is started closer to the center than the end face of the slab, the cutting is not completely performed.
In addition, continuous cast slabs have a dimensional change due to meandering and solidification shrinkage during casting, so a contact type end face detection device is provided to detect the end face, and the cutting start position and the end face detection position are set in the casting direction of the slab. It was common to make them parallel. However, usually, the width changing portion is not targeted for cutting because it is difficult to accurately detect the end surface of the slab because the end surface is not parallel to the casting direction, and it is difficult to set the start position. [0005] An object of the present invention is to provide a method for cutting a slab that can cut a slab even in a width changing portion where cutting has not been conventionally performed. The gist of the present invention is to provide a method of cutting a width-changed portion of a continuously cast slab of metal, the method comprising : End position detected by the contact type detector and the contact
A method for cutting a slab, characterized in that the slab is cut by determining the torch position at the start of cutting from the interval along the slab length direction of the slab. Hereinafter, the present invention will be described with reference to the drawings. FIG. 2 is a schematic view of the changed portion when the width of the slab is increased. By increasing the width of the casting mold 1 in order to increase the width of the slab, the slab 2 has a width change portion with an inclined end face.
FIG. 3 is a diagram schematically illustrating a conventional cutting method of the width changing unit. Until now, the cutting position was set to the wide side avoiding the width change part, after cutting the changed part in the slab of the narrow side and cutting the hatched part to match the width, Was wasting. FIG. 1 shows an example of a slab cutting apparatus according to the present invention.
The cutting device 9 can be moved parallel to the casting direction and is fixed by the slab clamp 6 to move in synchronization with the slab 2. A cutting torch truck 3 having a cutting torch 4 and a position detector 5 is installed on the cutting device so as to be movable in a direction perpendicular to the casting direction. The cutting torch cart 3 is a slab 2
, And each torch is cut from the end face of the slab toward the center. When the slab end face is detected by the position detector 5, the information is transmitted to the computer 7 for controlling the position of the torch truck, and the information of the slab width changing portion transmitted from the computer 8 for controlling the mold width (for example, the inclination of the width changing portion). , Length, etc.) to determine the cutting start position. An instruction signal is sent to the cutting torch truck 3 in accordance with the cutting start position information of the torch truck position control computer 7, and the cutting torch truck 3 moves accordingly to determine the position of the cutting torch 4.
Start cutting. The casting speed was set to 1.4 by a continuous casting machine for slabs.
When the casting width is changed from 1380 mm to 1530 mm at 50 mm / min on one side while operating at m / min, the width change part is 3
The gradient is 5.7 mm / m. The distance between the detector and the torch is 20
In the case of 0 mm, a correction of about 7 mm is required. Therefore, based on the information obtained in advance by the calculation as described above, the cutting at an arbitrary position of the width changing portion can be easily and accurately performed. According to the present invention described above, cutting can be performed even at the slab width changing portion, and the product yield is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory plan view showing an example of a slab cutting device according to the present invention. FIG. 2 is an explanatory plan view showing an example of changing the width of a slab. FIG. 3 is an explanatory view showing an example of a conventional cutting method of a width changing position. [Description of Signs] 1 mold 2 cast piece 3 cutting torch cart 4 cutting torch 5 position detector 6 cast clamp 7 torch cart position control computer 8 mold width control computer 9 cutting device

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B22D 11/16 104 B22D 11/126 B23K 7/00 508

Claims (1)

(1) In a method of cutting a width changing portion of a continuous cast slab of metal, the inclination of a slab end face of the width changing portion obtained in advance by calculation and a contact type detector are used. The detected end face position ,
Spacing of contact detector and cutting torch along slab length
A method for cutting a slab, wherein the slab is cut by determining a torch position at which cutting is started.