JPS59199145A - Long side synchronous continuous casting machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a long-side synchronous continuous casting machine, and particularly relates to a pair of fixed side plates and a pair of stretched movable plates that move while holding the fixed side plates. This invention relates to a fixed side plate structure near the hot water surface of a mold defined by a band-shaped body.

[Prior art]

In the current situation where it is required to directly roll the sections using heat for making without inserting the strips, it is desirable that the strips produced by a continuous milling machine be smooth and have no wrinkles on the thorn surface. . Incidentally, the flaws or wrinkles that occur on the surface of the slab often occur in the portion where the molten metal is first cooled in the mold and a solidified shell is formed. When the cause of this was investigated, it was found that it was due to the following reasons.

Generally, it is difficult to keep the molten metal level in the mold constant as the casting speed increases, and the molten metal level fluctuates. Particularly in a stationary mold, defects occur on the surface of the slab due to this fluctuation in the melt level. That is, in a stationary mold, the descending speed of the shaped solidified shell near the molten metal surface is slower than that of the lower solidified shell that has fully solidified. For this reason,
When a fluid level fluctuation occurs in a stationary mold, the solidified shell 2 formed along the inner surface of the stationary side plate 1 is exposed to the atmosphere near the fluid surface 3 (section 2A in the diagram), as shown in FIG. It will collapse inward due to heat shrinkage. After that, as shown in Fig. 2, when the molten metal level 3 rises, since molten metal generally has a large surface tension,
A depression 4 is formed, which becomes a hot water wrinkle on the +Jj katatsu surface. Areas with large water wrinkles are not cooled uniformly, resulting in defects such as cracks and flaws.

On the other hand, on the side of the movable side plate (movable strip) that moves synchronously with the movement of the slab, the movable side plate and the solidified shell are constantly trying to descend below the melt level, so even if the melt level fluctuates, the figure shown in Figure 1 As such, the phenomenon in which the upper two members of the solidified shell 2 are exposed to the atmosphere does not occur, and even if it does occur, it is extremely slight, and therefore wrinkles are hardly formed on the surface of the control piece. Therefore, in tJm where the short side of the section is formed by the fixed side plate and the long side is formed by the movable side plate, the long side of the 11 o'clock shape can obtain an extremely smooth surface quality, but the short side However, the disadvantage was that the quality deteriorated.

[Purpose of the invention]

An object of the present invention is to provide a long-side synchronous continuous casting wall that eliminates the above-mentioned drawbacks and is capable of producing slabs with good surface quality and no mold lines on the long and short sides. There is a particular thing.

[Summary of the invention]

The present invention consists of a pair of opposing fixed side plates that form a wall surface on the short side of the slab, and a fixed side plate that is moved in synchronization with the slab while being sandwiched from inside and outside to form a wall surface on the long side of the slab. In the long-side synchronous continuous casting machine, which has a @-type structure with a pair of movable side plates stretched over each other, a large number of gas ejection holes are installed near the hot water surface of the fixed side plate that forms the short side wall surface. A gaseous fluid ejected from the gas 1 negative outlet is provided between the inner surface of the fixed side plate and the solidified shell of the fishing piece, and the fixed side plate below the portion where the gas ejection hole is provided is By adopting a water-cooled configuration, the above object is achieved.

Next, the principle of the present invention will be explained. As shown in FIG. 1, the wrinkles on the Sakikata surface are caused by the solidified shell 2 near the hot water surface 3 being exposed above the hot water surface when the hot water surface 3 falls. The fixed side plate 1 is designed to eliminate the above-mentioned phenomenon. The method is
In the fixed side plate 1 in the vicinity of the molten metal surface in Fig. 1, the molten metal can be gradually cooled, and the short side solidified shell can be shifted to a position below the molten metal surface or made extremely thin. This is to eliminate the above phenomenon.

By the way, to slowly cool the upper part of the fixed side plate, you can use all materials such as refractories with low thermal conductivity, but if you use materials with low thermal conductivity, the thin solidified shell formed in this part will be If casting is continued in this state, a problem arises in that the solidified shell in this area cannot resist the pull-out force from below and breaks. Therefore, in order to prevent this, it is necessary to take measures to reduce the frictional force between the stationary side plate and the solidified shell.

In the present invention, as a means for this purpose, gas is ejected from the inner wall surface of the fixed side plate toward the outer wall surface of the solidified shell, and a gap is created between the inner surface of the fixed side plate and the outer surface of the solidified shell to significantly reduce the friction between the two. do. In this case, since a gas film is interposed between the fixed side plate and the solidified shell, the heat transfer coefficient therebetween can be reduced, and at the same time, it can be used as a means for slow cooling.

Furthermore, in the present invention, the fixed side plate below the gas jetting part of the fixed side plate is configured to be rapidly cooled by water cooling, thereby rapidly cooling the solidified shell in this part to obtain sufficient strength. shall have. This is because the solidified shell near the hot water surface is thin, so the strength of the solidified shell below it is increased so that the solidified shell can descend safely without delaying the speed at which the solidified shell is pulled downward. It is something to do.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to all the drawings.

FIGS. 1 and 2 are explanatory diagrams showing an embodiment of a long-side synchronous continuous casting machine of the present invention. The bath water 6 in the tundish 5 is continuously poured into the trout mold through a nozzle 7. The short sides of the diseased type are formed by a pair of fixed side plates 34, 35 which are curved as shown in FIG. 3 so that the section 32 can be shaped into a curved shape. The curvature of the curvature varies depending on the scale of the equipment, but by appropriately selecting it, a mold having the required slab cooling length can be constructed. For example, if the radius of curvature is 2.5 m, the mold length will be about 4 m. Further, on the exit side of the mold, the curvature gradually changes so that the slab 32 can be drawn out in a straight line. On the long side of the mold, while holding the fixed side plates 34 and 35 along the curved surface from the inside and outside, press the ttjJ piece 32.
It is formed of a pair of movable band-like bodies 8 and 9 that move apart from each other. This is possible! The rI+ strips 8 and 9 are both rollers 10.
, 11.12 and rollers 13, 14.15 and tensioned by springs 16.17. Note that each of the movable strips 8 and 9 can be configured to actively move in synchronization with the slab by a drive device (not shown), if necessary. Connection to rollers 12, 15 located on the sides is more effective in improving the tension of the strip.

On the back side of each movable strip 8, 9, corresponding to the mold wall, a hydrostatic bearing device 18, 19 is provided for cooling and load supporting the strip.

This hydrostatic bearing device 18, 19 is defined by the movable strips 8, 9 (- arranged in such a way that it can support and cool the strips over almost the entire area of construction); Each of them has an ice chamber 20, 21 inside, and pockets 22, 23 are formed facing the movable strips 8, 9. The ice chambers and the pockets communicate with each other through a number of nozzles 24, 25.

Thus, by introducing high-pressure cooling fluid from the outside into the ice chamber 20.21, the high-pressure cooling fluid flows from the nozzle 24.25 into the pockets 22.23 and the movable strips 8, 9. It is then ejected in the width direction as shown by the arrow in Fig. 3. During this flow process, each movable strip 8, 9 and the hydrostatic bearing device 18.
A thin fluidized bed of cooling fluid is formed between the fixed side plates 34.
Perfect contact between 35 and the movable strips 8.9 and support of bath water static pressure are achieved, as well as effective cooling of the movable strips 8 and 9. The springs 16 and 17 are connected to the protruding members 26 and 27 of the hydrostatic bearing device and the roll support 28°2, respectively.
It is located between 9. On the other hand, the fixed side plates 34 and 35 are configured to be movable and adjustable in the width direction to accommodate changes in the width of the slab 32. That is, the fixed side plates 34, 35 have two arms 36, 37 fixedly mounted on the upper and lower sides, respectively, and guides 38, 37 provided on the arms 36, 37. ．． 3
9 was connected to the hydrostatic bearing device. l1a40,41
It is supported so as to be slidable in the axial direction. A hole 42.43 is provided at the other end of the arm 36.37, and a screw 44.45 connected to the hydrostatic bearing device is inserted into the hole 42.43.
7 and washers 48,49.
37 is configured to be fixed to the screw 44.45. Therefore, by adjusting the movement of the NANDs 46, 47, the widthwise position of the fixed side plates 34, 35 can be changed. Furthermore, the fixed side plate 34.35 and the arm 36.37 are provided with lubrication holes 50.51, in order to reduce the sliding resistance between the fixed side plate 34.35 and the movable strips 8, 9. This is for supplying lubricant such as carbon to the sliding surface through supply pipes 52 and 53.

5 and 6 are detailed enlarged views of the entrance side portion of the long-side synchronous continuous casting machine shown in FIG. 3. In the vicinity of the hot water surface 55, a fixed side plate 57 for slow cooling on the short side having a large number of ejection holes 56 from which gas is ejected is arranged on the left and right sides, and a lower part of the fixed side plate 57 for slow cooling has an internal water cooling groove 58. A fixed side plate 5 for rapid cooling made of @ and formed so that the cooling water flows in the direction of the arrow.
The fixed side plate 57 for slow cooling and the fixed side plate 59 for rapid cooling are supported by a reinforcing plate 60 on their back surfaces. A gas chamber 61 is provided in a portion of the reinforcing plate 60 corresponding to the ejection hole 56, and the gas chamber 61 communicates with the outside through a hole 62.

A cooling water channel is formed by the internal water cooling groove 58 of the fixed side plate 59 for rapid cooling and the reinforcing plate 60, and the reinforcing plate 60 is provided with a discharge hole 63 through which cooling water is discharged.

Next, the @ operation of this embodiment will be explained. When argon or nitrogen gas is sent to the gas chamber 61 through the hole 62, the gas is ejected from the ejection hole 56 of the fixed side plate 57 for slow cooling. This gas is interposed between the solidified shell 64 and the fixed side plate 57 for slow cooling, and in order to reduce the thermal conductivity of this portion, the solidified shell 64 is designed to be thin. Cooling water is sent to the internal water cooling grooves 58 of the fixed side plate 59 for rapid cooling, and the solidified shell 65 in contact with the fixed side plate 59 for rapid cooling is rapidly cooled and shaped to have sufficient strength and thickness.

Therefore, the solidified shell of the arm piece produced by the continuous casting machine of this embodiment is very thin in the vicinity of the molten metal surface 55, and is approximately 0.63 to 1 mm thick. In addition, in the conventional row, the thickness was about 2 to 5 mm. Moreover, the temperature in this part is high because heat conduction is obstructed by the gas ejected from the nozzle 56, and the fall of the thin solidified shell 64 when the melt level falls is small, so there are almost no melt wrinkles in this part. It is so small that it can be ignored. On the other hand, the solidified shell 65 near the quenching fixed side plate 59 at the bottom of the solidified shell 64 is rapidly cooled and has sufficient strength and thickness. Therefore, when pulling out the piece, the drawing blade can be reliably transmitted to the thin solidified shell 64 by passing through the solidified shell 65 having sufficient strength. At this time, the thin solidified shell 64 breaks due to sliding resistance with the fixed side plate 57 for slow cooling.
Since the solidified shell 64 of the gas fluid injected from the ejection hole 56 is in a non-contact state with the fixed side plate 57 for slow cooling, the frictional force between them is reduced and the solidified shell 64 can be safely pulled out downward. It has become a VC. By the way, since the long side of the mold of the continuous casting machine of this embodiment is composed of a movable strip 9, the long side of the mold is similar to the conventional Nu.
The mold is cooled to form a strong solidified shell. Therefore, since the strong solidified shell formed on the long side drags the thin solidified shell 64 on the short side downward and moves the entire solidified shell downward, the solidified shell on the short side Even if the tip of 64 is thin and weak, the solidified shell can be safely pulled out.

Note that the diameter of the jet hole 56 of the fixed side plate 57 for slow cooling is 0, 1.
= approximately 0.3 rrun, and the gap between the thin solidified shell 64 and the slow cooling fixed side plate 57 is maintained at 20 to 50 μml. Further, the pressure of the gas to be injected requires even more pressure than the static pressure of the molten metal. Furthermore, since the depth of the ejection hole 56 from the hot water level is required to be about 100 m, the pressure required when storing steel material is about 0.08 to 1/crjl.

According to this embodiment, the short side of the mold in the vicinity of the hot water surface is constituted by the fixed side plate 57 for slow cooling and the fixed side plate 59 for rapid cooling, and the gas is ejected through the jet holes 56 of the fixed side plate 57 for slow cooling. By passing cooling water through the internal water cooling groove 58 of the fixed side plate 59 for rapid cooling to form a solidified shell, a thin solidified shell 64 is formed near the hot water surface 55, thereby minimizing hot water wrinkles in this area. This has the effect of improving surface quality. Furthermore, even if a thin solidified shell 64 is formed, the solidified shell 65 continuing below and having sufficient strength can transmit the solidified shell pulling force to the sufficiently thin solidified shell 64. Gas is present between the fixed side plate 57 for slow cooling and reduces the frictional force in this part, so that the entire solidified shell can be safely drawn out of the sub-mold. Therefore, according to this embodiment, as in the past, a high-quality cast slab is produced that has no hot water wrinkles on the long side surface that contacts the movable strips 8 and 9 and also on the short side surface. be able to.

Although this embodiment describes the A type with grooved surfaces, it goes without saying that the present invention can also be applied to a continuous casting machine having a mold configured in a straight line. The present invention can be applied to any continuous casting machine that has a mold whose sides are movable strips that can move in synchronization with the slab. Furthermore, although the fixed side plate for slow cooling in the above-mentioned embodiments has artificially processed ejection holes 56, the same effect can be obtained even if porous torus brick or the like is used in this part.

〔Effect of the invention〕

As described above, according to the long-side synchronous continuous casting method of the present invention, gas is ejected from the vicinity of the hot water surface of the fixed side plate constituting the short side of the mold to slowly cool this portion. By configuring the fixed side plate below the gas jetting part to be rapidly cooled, it is possible to produce grapes with good surface quality and few hot water wrinkles on both the long side and short side surfaces.

[Brief explanation of drawings]

FIGS. 1 and 2 are explanatory diagrams showing about 1a where wrinkles are formed on the surface of one piece, and FIG. 3 is an explanatory diagram showing an embodiment of the long side synchronous continuous casting machine of the present invention Figure 4 is a sectional view taken along the line 1--ya in Figure 3, and Figure 5 is a detailed view of the entry side of the mold shown in Figure 3. The enlarged sectional view of Pd, FIG. 6, is a sectional view of the central part of FIG. 8.9...Movable belt state, 18.19...Static pressure bearing device, 32...; Flange piece, 34.35... Fixed side plate, 5
5... Hot water surface, 56... Spout hole, 57... Fixed side plate for slow cooling, 58... Internal water cooling rK, 59... Fixed side plate for rapid cooling, 60... Reinforcement plate, 4th Figure 1 Figure B

Claims (1)

[Claims] 1. Consisting of a fixed side plate that forms the wall surface on the short side of the slab, and a movable band-shaped body that moves in synchronization with the movement of the slab to form the wall surface on the long side of the slab. In a long-side synchronous continuous casting machine that has a mold, molten metal is injected from the inlet side of the mold, and slabs are pulled out from the outlet side, a large number of gas ejection holes are provided in the fixed side plate near the molten metal surface on the inlet side of the mold. A long-side synchronous continuous casting machine, characterized in that the gas is interposed between the solidified shell of the molten metal near the surface of the molten metal and the stationary side plate. 2. The long-side synchronous continuous casting machine according to claim 1, wherein the downstream stationary side plate connected to the stationary side plate provided with the gas ejection holes has a cooling water passage for rapid cooling. .