JP5097601B2 - Billet cutting equipment - Google Patents

Description

  The present invention relates to a steel slab welding apparatus for welding a surface of a slab or a steel slab (hereinafter referred to as a steel slab) in a continuous casting process or a rolling process.

  At the time of manufacturing the steel slab 5, in the steelworks, in order to remove cracks, pinholes or inclusions caused by the inclusions on the surface layer of the steel slab 5, the upper and lower surfaces of the high-temperature steel slab 5 or both side surfaces are removed. The surface is cut by a steel piece cutting device. Therefore, the steel slab cutting device is positioned as one of the indispensable facilities for improving the quality of the steel slab 5.

  1 and 2 are schematic diagrams showing an example of a steel piece cutting apparatus.

  The figure shows a type of cutting apparatus in which the upper and lower surfaces and side surfaces of the steel piece 5 are simultaneously welded. The upper surface torch unit 1 and one side surface side torch unit 3 are integrally coupled, and the lower surface torch unit 2 and the other side are combined. The side torch unit 3 is integrally coupled. That is, L-shaped torches are arranged facing each other across the steel piece 5. Since the steel slab 5 changes in width and sometimes thickness, the upper surface torch unit 1 and the lower surface torch unit 2 are configured to slide in the width direction of the steel slab 5, and the side torch unit 3 is fixed. There is a mechanism that slides in the thickness direction of the steel piece 5.

  Next, the movement of the welding apparatus will be described.

  After the steel slab 5 conveyed on the roll 4 stops at the welding start position, the torch unit on the upper and lower surfaces of the welding machine slides in the width direction of the steel slab 5 to the width of the steel slab 5. Stop at the same time. In the type in which the torch units 3 on both side surfaces slide in the thickness direction of the steel slab 5, the torch units on the upper and lower surfaces and the torch units 3 on the side surfaces are prevented from interfering during sliding in the width direction of the upper and lower surface torch units. As shown in FIG. 3 (a), the thickness direction slide mechanism 14 temporarily moves the side torch unit 3 in the thickness direction so that there is a space of several tens of millimeters between the upper and lower torch units and the side torch unit 3. Slide it. After the upper and lower torch units slide in the width direction, as shown in FIG. 3B, the torch units on both sides slide in the thickness direction, approach the upper and lower torch units, and stop according to the thickness of the steel slab 5 To do. FIG. 2A and FIG. 2B show a state in which they are stopped according to the steel pieces 5 having different widths. At this time, the side torch unit 32 coupled to the upper surface torch unit 1 side is provided with a gap 11 of about 10 mm so as not to contact the lower surface torch unit 2. Similarly, the side surface torch unit 31 coupled to the lower surface torch unit 2 is provided with a gap 11 between the upper surface torch unit 1. Here, the type in which the side torch unit 3 does not slide in the thickness direction maintains a certain distance from the upper and lower surfaces in advance. Therefore, in any type, there is a gap 11 between the side surface torch unit 3 and the upper and lower surface torch units at the time of cutting.

  After the upper and lower surface torch units are slid and set in the width direction, the slab 5 is preheated by injecting combustible gas from the upper surface torch unit 1 and burning, and when preheating is completed, high pressure oxygen is injected and dissolved. The entire surface layer of the steel slab 5 is cut while moving the cutting device or the steel slab 5.

  Here, in the case where the welding apparatus only cuts the upper surface or only the upper and lower surfaces, the molten slag (hereinafter referred to as Noro 6) generated during the cutting droops to the side surface and solidifies (hereinafter referred to as “slag”). The fins 7 remain attached to the side surfaces of the steel slab 5. If rolling is performed in a lower process while leaving the fins 7, the fins 7 cause wrinkles, and an operation for removing the fins 7 is necessary. This removal work is usually carried out with a hand scarf by human power, which is a harsh work environment of high heat and heavy work, and there is a problem that work efficiency is poor due to offline work.

  Further, even in a type of cutting apparatus that performs not only the upper and lower surfaces but also the side surfaces, there is a gap 11 between the side torch unit 2 and the upper and lower surface torches as described above, and the fins of the portion facing the gap portion are provided. 7 remained as usual.

  Therefore, as a method for removing the fins 7 online, conventionally, in Patent Document 1, a separate fluid injection port is provided, and high pressure air or water, a mixed fluid of air and water, or an inert gas is supplied from the fluid injection port to the steel. A method of ejecting toward the short side of the piece 5 and removing the fins 7 has been proposed.

  Patent Document 2 proposes a method of removing a fin 7 by providing a dedicated fluid ejection port, injecting high-pressure oxygen from the fluid ejection port toward the fin generating portion.

JP 58-13473 A JP 2003-334655 A

  However, in the technique described in Patent Document 1, when air or water is used as the jetting fluid, the cooling effect is large, and the temperature of the steel slab 5 is lowered. In addition, since air or water is jetted perpendicularly to the direction of travel of the steel slab 5, there is a possibility that it interferes with the gas for cutting the upper surface and causes defective cutting on the upper surface. Further, when water is used, special care is required because there is a risk of reacting with the molten Noro 6 to cause a steam explosion.

  Moreover, in the method of patent document 2, a dedicated apparatus is installed in the vicinity of the torch for cutting, and the equipment cost increases. In addition, there is a problem that it is difficult to install the apparatus because the installation location is narrow.

  The problem to be solved by the present invention is to provide a billet cutting apparatus that can easily remove the fins 7 generated when the billet 5 is cut and has a low maintenance cost and a low maintenance cost. .

The present invention is a steel piece melting apparatus capable of solving the drawbacks of the conventional methods as described above, and the gist thereof is characterized by having the configurations shown in the following (1) to ( 4 ).
(1) It has an upper surface side torch disposed in the upper surface width direction of the steel slab and a side surface torch disposed on at least one side surface of the steel slab, and oxygen gas from the upper surface side torch and the side surface torch Alternatively and / or in the steel piece slab cutting apparatus for cutting the steel slab surface by moving the torch or the steel slab while injecting combustion gas, the discharge direction of the gas injected from the side torch is: A steel slab of gas injected from the uppermost part of the side-side torch at the collision position of the gas injected from the upper-surface side torch with the steel slab, which is inclined to the upper surface side with respect to the length direction of the steel slab An apparatus for cutting a steel slab, characterized in that the gas slab length direction is 40 to 100 mm upstream from the position where the gas reaches the upper surface .
(2) The side torch is a slit-type torch, and a current plate is provided in the torch so that the gas discharge direction from the torch is inclined to the upper surface side with respect to the length direction of the steel piece. The steel slab welding apparatus according to (1), characterized in that:
(3) The ratio (l / w) between the length (l) of the gas flow direction in the gas flow direction and the interval (w) between the gas flow paths partitioned by the current plate is 0.7 to 2.0. The apparatus for cutting and cutting steel slab according to the above (2), characterized in that it is installed as described above .
(4) scarfing when to have performed, the injection velocity of the gas, the is characterized in that a 400 to 500 times the moving speed of the torch or the steel strip (1) to (3) Steel billet cutting apparatus according to any one of the above.

  With respect to the steel slab 5 subjected to the cutting by the present invention, it is possible to reliably remove the fin 7 attached to the short side at a low cost, and it is possible to prevent the deterioration of the quality without impairing the productivity.

  Hereinafter, an embodiment according to a steel piece melting apparatus of the present invention will be described with reference to the drawings.

  The present invention includes an upper surface side torch disposed in the upper surface width direction of the steel slab, and a side surface torch disposed on at least one side surface of the steel slab, and oxygen gas from the upper surface side torch and the side surface torch Alternatively, and / or a steel slab welding apparatus for cutting the steel slab surface by moving the torch or the steel slab while injecting combustion gas.

  FIG. 4 is a schematic view of an example of a steel piece melting apparatus according to the present invention.

  The figure shows an example of a cutting apparatus for cutting the upper and lower surfaces and the side surface according to the present invention, and the side torch unit 3 is a fixed type having no thickness direction sliding mechanism. When performing the cutting, the cutting apparatus is fixed, and the upper and lower surfaces of the steel piece 5 and the surface layer of the side surface are cut by moving the steel piece 5 in the direction of the white arrow.

  As shown in FIG. 4, a gap 11 exists between the side torch unit 3 and the top torch unit 1 as in the conventional cutting and cutting apparatus. However, in the cutting apparatus of the present invention, the discharge direction of the gas injected from the side surface torch is inclined to the upper surface side with respect to the length direction of the steel slab. For this reason, since the gas flow 12 injected from the side torch unit 3 is injected obliquely upward, the noro 6 flowing out to the side surface is blown off by the injection flow, so that the fin 7 is formed downstream of the torch of the steel slab 5. Does not remain.

  Preferably, in the present invention, the side torch is a slit-type torch, and a current plate is provided in the torch so that the gas discharge direction from the torch is inclined to the upper surface side with respect to the length direction of the steel piece. . FIG. 5 shows an example of a method of inclining the gas injection direction from the side torch unit 3 in the upper surface direction. In the figure, a rectifying plate 8 is installed in the slit 13 of the existing side torch unit 3, the gas flow is inclined to the upper surface side, and the gas injection direction is inclined to the upper surface side by an angle θ. .

  At this time, the length of the current plate 8 to be installed has an optimum range depending on the distance between the current plates 8 or the side wall of the torch unit and the current plate 8. The ratio between the length (l) of the current plate 8 and the interval (w) is preferably 0.7 to 2.0. If this ratio is less than 0.7, the controllability of the injection direction cannot be satisfied, and if it exceeds 2.0, the pressure loss increases. Further, if the length of the rectifying plate 8 is too long with respect to the depth of the torch unit, the rectifying plate 8 will melt, and if it is shortened, the gas injection direction cannot be controlled. % To 85% is desirable.

  As described above, in the existing fusing device, the method of installing the rectifying plate 8 on the side torch unit 3 is a low-cost modification, and a predetermined effect can be obtained.

  On the other hand, when installing a new cutting apparatus, the injection direction of the side torch unit 3 may be inclined from the beginning to the upper surface side.

  FIG. 6 explains the relationship between the collision position (P1) of the injection gas from the upper surface torch unit 1 to the steel piece 5 and the position (P2) where the injection gas from the side torch unit 3 reaches the upper surface of the steel piece 5. FIG. The position of P2 is determined by L1 and the injection angle θ.

  Assuming that the distance between P1 and P2 is Dp, if Dp is less than 40 mm, the upper surface cutting gas is interfered with and defective cutting occurs. If it exceeds 100 mm, the removal of the fins 7 becomes insufficient. Therefore, it is desirable that Dp be 40 mm to 100 mm.

  Moreover, the gas flow rate at the time of gas injection of the side torch unit 3 is preferably 400 to 500 times the steel piece moving speed. If it is less than 400 times, the removal of fins is insufficient, and if it is more than 500 times, it interferes with the upper surface cutting gas and causes defective cutting. Here, the gas flow rate can be obtained by dividing the gas flow rate by the slit cross-sectional area.

  Further, due to the effect of the present invention, even if the side surface torch unit 3 is not provided with a thickness direction sliding mechanism, the gap 11 between the upper surface torch unit 1 and the side surface torch unit 3 is finned even if a sufficient space is maintained so that they do not contact each other. Since the problem of remaining 7 is solved, the apparatus can be further simplified.

  The present invention was applied on an actual machine. Table 1 shows the implementation conditions and implementation results. The top and bottom surfaces and the side surfaces have torches, and the side surface side torches are slit type torches. At the time of scarf, the gap 11 between the upper and lower torch units and the side torch unit is 35 mm. The number of steel slabs in which fins were generated / the number of steel slabs processed by the steel slab cutting apparatus × 100 was defined as a fin generation rate (%).

  Condition 1 was a conventional torch without a current plate. Conditions 2 to 11 are such that the discharge direction of the gas injected from the side-side torch is inclined by 17 ° on the upper surface side with respect to the length direction of the steel slab by providing the current plate of the present invention. As a result, in terms of conditions 2 to 11, the fin occurrence rate was reduced as compared with condition 1 in which the current plate was not provided.

  Condition 2 is that the ratio (l / w) between the length (l) in the gas flow direction and the interval (w) between the gas flow paths partitioned by the rectifying plate is 0.5, which is smaller than the preferred range of the present invention. Therefore, the gas discharge direction could not be sufficiently inclined to the upper surface side, and the effect of improving the fin occurrence rate was limited. In Condition 3, since the ratio (l / w) was 2.5, which was larger than the preferred range of the present invention, the injection speed decreased to 380 times, and the effect of improving the fin occurrence rate was limited. In condition 4, the injection speed was lower than the preferred range, and the effect of improving the fin occurrence rate was limited. Condition 5 was that the injection speed was higher than the preferred range and the occurrence rate of fins was suitable, but there were cases where defective welding occurred. In condition 6, the distance Dp between P1 and P2 was longer than the preferred range, and the effect of improving the fin occurrence rate was limited. Condition 7 had a Dp of zero and caused interference with the upper surface cutting gas, and although the occurrence rate of fins was favorable, there was a case where defective cutting occurred. In the conditions 8 to 11 carried out under the most preferred conditions of the present invention, it was confirmed that there was no occurrence of fins 7 and a good side face could be secured.

It is a figure which shows the outline | summary at the time of seeing the welding apparatus in a prior art from the side. It is a figure which shows the outline | summary at the time of seeing a welding apparatus from the front, (a) (b) is a figure which shows the outline | summary in the case of steel-cutting a steel piece from which width differs, respectively. It is a figure which shows the positional relationship of an upper-lower surface torch unit and a side torch unit, (a) is a figure before a slide, (b) is a figure which shows the side torch unit after a slide. It is a conceptual diagram which shows an example of the welding apparatus by this invention. It is a figure which shows the side torch which incorporated the baffle plate by this invention. It is a figure which shows the relationship of each jet direction of the upper surface torch by this invention, and a side torch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper surface torch unit 2 Lower surface torch unit 3, 31, 32 Side torch unit 4 Conveyance roll 5 Steel piece 6 Noro 7 Fin 11 Space | interval 12 Gas flow 13 Slit 14 Thickness direction slide mechanism

Claims (4)

An upper surface side torch disposed in the upper surface width direction of the steel slab, and a side surface torch disposed on at least one side surface of the steel slab, and oxygen gas or / and / or from the upper surface side torch and the side surface torch In the steel piece slicing apparatus for slicing the steel slab surface by moving the torch or the steel slab while injecting combustion gas,
The discharge direction of the gas injected from the side surface side torch is inclined to the upper surface side with respect to the length direction of the steel slab ,
The collision position of the gas injected from the upper surface side torch to the steel piece is 40 to 100 mm in the length direction of the steel piece from the position where the gas injected from the top of the side surface torch reaches the upper surface of the steel piece. An apparatus for cutting a steel slab characterized by being upstream of the injection direction .   The side-side torch is a slit-type torch, and a current plate is provided in the torch so that the gas discharge direction from the torch is inclined to the upper surface side with respect to the length direction of the steel piece. The steel piece melting apparatus according to claim 1.   In the rectifying plate, the ratio (l / w) between the length (l) in the gas flow direction and the interval (w) between the gas flow paths partitioned by the rectifying plate is 0.7 to 2.0. The slab melting apparatus according to claim 2, wherein the apparatus is installed. The steel according to any one of claims 1 to 3 , wherein when performing the cutting, the gas injection speed is 400 to 500 times the moving speed of the torch or the steel slab. A piece of cutting equipment.

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