JPS6344166Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention is a finishing mill exit immediate quenching device that cools hot rolled steel sheets immediately after exiting the hot finishing mill, and is particularly designed to reduce the occurrence of surface scale on hot rolled steel sheets. This invention relates to a quenching device for water-cooling hot-rolled steel sheets on the exit side of a hot finishing mill. (Prior Art) Conventionally, hot-rolled steel sheets generate surface scale during the manufacturing stage, so it has been customary to undergo pickling treatment for the purpose of descaling prior to cold rolling.
Since this pickling process uses large amounts of strong acids such as hydrochloric acid and sulfuric acid, there are many problems in terms of equipment maintenance, pollution prevention, and hygiene. If the amount of scale adhesion on the surface of hot rolled steel sheets increases, which is desired to be reduced or omitted, it becomes difficult for the acid solution to penetrate, making it necessary to extend the pickling time, pickling line, etc. Since the degree of burden on pickling is greatly affected by the amount of scale adhesion, measures have been taken to reduce the burden of pickling by manufacturing thin scale hot rolled steel sheets with as little scale adhesion as possible. There is. In conventional hot-rolled steel plate manufacturing equipment, as shown in FIG. 8, a high-temperature steel plate 2 leaving a hot finishing mill 1 is air-cooled in the atmosphere on a table roller 3 of an exit hot run roller table. After moving while moving, the material enters a zone cooling device 4, where it is cooled by spray injection to a temperature suitable for winding, and is wound into a winder 5. The scale mentioned above is said to be mainly caused by the high temperature steel plate after finish rolling being oxidized by contact with air while moving on the hot run table for about 10m, and scale control measures for conventional thin scale steel plate production are required. In order to shorten the high-temperature residence time of the steel plate, the water cooling pattern by the zone cooling device 4 has been changed to a pre-quenching type. However, such a method cannot be expected to produce a thin-scale steel plate with an extremely small amount of scale adhesion, and cannot be said to be a sufficient measure to reduce or omit the burden of pickling. (Problem to be solved by the invention) For this reason, the invention aims to suppress scale formation and obtain a thin-scale hot rolled steel sheet in a coiled state after passing through a conventional zone cooling device. From the moment the hot rolled steel sheet is cooled, it is immediately cooled at a high cooling rate.
It is an object of the present invention to provide a quenching device immediately adjacent to the exit side that can efficiently cool the temperature to a temperature below ℃. (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention is designed to immediately quench the hot-rolled steel sheet that comes out of the roll bite of the hot final rolling mill, so that both the hot-rolled steel sheet and the work rolls are cooled. The present invention aims to provide an exit-side immediate quenching device suitably configured and arranged so as to simultaneously and efficiently cool the hot final rolling mill, as shown in Fig. 1. A cooling water nozzle 9 opened on the lower surface 8a of a flat plate-shaped outlet movable guide 8 that guides the hot rolled steel sheet 2 coming out of the roll bite of the upper and lower work rolls 6, 7 onto the outlet table roller 3, and a cooling water nozzle 9 opened on the lower surface 8a of the outlet movable guide 8. 8 on the exit side table roller 3 at a predetermined interval and approximately parallel to the upper surface 2a of the hot-rolled steel plate 2 (see FIG. 2); A tip protrusion 10 having a cooling water flow guide curved surface 10a provided at the roll bite side end 8b apart from the upper work roll circumferential surface 1b and curved upward along the circumferential direction of the upper work roll circumferential surface.
and a draining roll 11 provided so as to be in contact with the upper surface 2a of the hot rolled steel plate 2 at the end 8c on the opposite side to the roll bite side end 8b of the exit side movable guide 8. In FIG. 1, reference numeral 12 denotes a lower cooling water nozzle, and 13 a lower cooling water nozzle, which is spaced apart from the tip projection 10 at an appropriate distance and protrudes from the outlet movable guide 8 across the entire width of the outlet movable guide 8. weir board, 14
15 is a common pipe for uniformizing the cooling water supplied to the cooling water nozzle 9; 15 is a cooling water supply flexible hose connected to the common pipe 14; 16 and 17;
indicates a vertical back-up roll. (Function) According to the above-described configuration, the steel plate 2 to be hot rolled is passed between the upper and lower work rolls 6 and 7 of the final stand of the hot finishing mill, and the tip of the steel plate 2 is passed through the winder 5 (the eighth
(see figure), and after the waving of the steel plate 2 on the hot run table roller 3 disappears, the exit side guide lifting device is controlled to lower the exit side movable guide 8 as shown in Fig. 1. The lower surface 8a of the lever is held at a horizontally upper position spaced apart from the upper surface 2a of the hot-rolled steel plate 2 at a predetermined interval of, for example, 5 to 15 mm and substantially parallel to the upper surface 2a of the hot rolled steel plate 2. As a result, for example, when pressurized cooling water is fed from the flexible hose 15 through the common pipe 14, the cooling water flows between the lower surface 8a of the outlet movable guide 8 and the hot rolled steel plate 2 as shown by the arrow from the cooling water nozzle 9. It is ejected into the gap with the surface 2a, flows toward the open end of this gap on the roll bite side, and flows between the curved surface 10a of the tip projection 10 of the exit side movable guide 8 and the work roll surface 6a. , overflows over the tip protrusion 10, thereby rapidly cooling the upper work roll 6, particularly the roll bite portion and the hot rolled steel sheet 2 coming out of the roll bite, with cooling water. After cooling the hot rolled steel sheet 2 and the work roll 6 as described above, the cooling water flows through the tip projection 10.
The liquid flows over the upper surface of the movable outlet guide 8, flows laterally on the movable outlet guide 8 between it and the weir plate 13, and flows down to both sides of the movable guide 8. In addition, the roll bite side end 8 of the exit side movable guide 8
A draining roll 11 is provided on the end 8c opposite to b to prevent the cooling water jetted from the cooling water nozzle 9 from flowing out in the opposite direction to the roll bite direction. Although not shown, it is possible to install a thickness gauge, a plate temperature gauge, and other measuring instruments that may be adversely affected by water immediately after the draining roll. (Embodiment) FIGS. 2 and 3 show one embodiment of the present invention. In the figure, reference numeral 8 denotes a flat outlet movable guide having a cooling water nozzle 9 in the form of a slit opening in the lower surface 8a and extending in the width direction, as described above with reference to FIG. A tip protrusion 10 having a curved surface 10a is provided at the roll bite side end 8b along the circumferential surface 6a of the work roll 6,
A weir plate 13 is provided on the upper surface 8d apart from the tip projection 10. Further, a common pipe 14 communicating with the cooling water nozzle 9 is attached to the upper surface 8d. Further, the draining roll 11 is attached to the side plate 20 fixed to both sides of the exit side movable guide 8 by means of a shaft 21, at a position where it can come into contact with the hot-rolled steel plate at an end 8c on the opposite side to the roll bite side end 8b. It is rotatably mounted. The exit side movable guide 8 configured as described above has a hooking pin 2 that projects laterally at the rear end of the side plate 20.
2, and is fixedly provided on the opposing surface 23a of the outlet wall 23 of the rolling mill housing.
A guide pin 22 is engaged with the guide pin 22, thereby guiding the vertical movement of the exit movable guide 8. As a guide lifting device for the exit movable guide 8, a pair of guide front end lifting cylinder devices 2 are connected between the front end of the exit movable guide 8 and the upper part of the exit wall 23 of the rolling mill housing.
A pair of cylinder devices 26 for raising and lowering the rear end of the guide are connected between the rear end of the movable exit guide 8 and the upper part of the exit wall 23 of the rolling mill housing. Cylinder device 2 for lifting and lowering the front end of the guide
A bracket 5 is connected at the base end of the cylinder 27 to a support rod 28 extending in the width direction between the outlet walls 23 of the rolling mill housing, and whose tip or lower end is fixed to the front end of the outlet movable guide 8 to the piston rod 29. 30 by a pin 31.
On the other hand, the cylinder device 26 for raising and lowering the rear end of the guide is
The front end of the cylinder 32 is connected to the housing exit wall 2.
The piston 35 is swingably connected to a bracket 33 on the top of the piston 3 by a trunnion shaft 34, and the tip or lower end of the piston 35 is pin-connected to the rear end of the side plate 20 by a pin 36. With the above configuration, the cylinder devices 25 and 26 for raising and lowering the front and rear ends of the guide are controlled by a suitable automatic control device to hold the exit side movable guide 8 in the position shown in FIG. 2, and the cooling water is supplied at 2 to 3 kg/cm. By feeding the water at a pressure of ² and ejecting it from the cooling water nozzle,
As described above with reference to FIG. 1, the hot-rolled steel sheet coming out of the roll bite can be immediately quenched and at the same time the work rolls can be sufficiently cooled. Fig. 4 shows that during the first passing of the hot rolled steel 2 that has passed between the upper and lower work rolls 6 and 7 of the final stand of the finishing rolling mill, the steel plate waves on the table roll 3, so the front and rear ends of the guide are used to raise and lower the steel plate. The cylinder devices 25 and 26 are controlled to thread the exit side movable guide 8.

【table】

[Table] As is clear from these figures, in curve B obtained by the conventional device, the scale thickness increases over time due to normal cooling, reaching 5 to 6 μm.On the contrary, in curve A obtained by the present invention, the scale thickness increases due to the recent rapid cooling. Scale growth is suppressed and almost no scale is maintained (approximately 0.5 μm). (Effects of the invention) According to the apparatus of the present invention, scale on the surface of a hot rolled sheet can be significantly reduced compared to conventional apparatuses.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the main parts of the hot finishing mill exit side immediate quenching equipment according to the present invention, Figure 2 is an overall schematic diagram of the exit side immediate quenching equipment shown in Figure 1, and Figure 3 is the FIGS. 4 and 5 are schematic diagrams similar to FIG. 2 showing the exit movable guide in various different positions; Figure 6 is a graph comparing the state of scale formation on the surface of a hot rolled steel sheet when the immediate quenching device of the present invention is used and the conventional cooling device. FIG. 8 is a graph showing a comparison of temperature changes of a hot-rolled steel sheet caused by a cooling device, and is a schematic diagram of the exit side portion of a conventional hot finishing rolling mill. 1... Hot finishing rolling mill, 2... Hot rolled steel plate, 3...
... Output table roller, 4 ... Zone cooling device, 5 ... Winder, 6 ... Upper work roll, 7 ...
...Lower work roll, 8...Output side movable guide, 9...
... Cooling water nozzle, 10 ... Tip projection, 11 ... Draining roll, 12 ... Lower cooling water nozzle, 15 ...
...Cooling water supply flexible hose, 25... Cylinder device for elevating the front end of the guide, 26... Cylinder device for elevating the rear end of the guide.

Claims (1)

[Scope of utility model registration request] A cooling water nozzle opened at the lower surface of a flat plate-shaped exit movable guide that guides the hot rolled steel sheet coming out of the roll bite of the upper and lower work rolls of the hot final finishing mill onto the exit table roller; a guide lifting device that is held at an operating position that is spaced substantially parallel to the upper surface of the hot rolled steel plate at a predetermined interval; a tip projection having a cooling water flow guide curved surface curved upward along the circumferential direction on the circumferential surface of the work roll; and a tip protrusion having a cooling water flow guide curved surface curved upward along the circumferential direction, and a tip protrusion on the hot rolled sheet surface at an end opposite to the roll bite side end of the exit side movable guide. A quenching device immediately before the exit side of a hot finishing rolling mill, characterized by comprising a draining roll provided so as to be in contact with the draining roll.