JP2006326625A - Cast iron bar having deformed cross section, and continuous casting method and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for continuously casting a cast iron bar having a deformed cross section with good quality. <P>SOLUTION: In the continuously casting method for cast iron bar 11 having the deformed cross section, a graphite die 4 comprises a deformed inner hole 8 corresponding to the deformed cross section shape of the cast product and a water-cooling jacket 5 is arranged around the graphite die to cool the die, and molten iron is poured into the graphite die, and the cast iron bar having the deformed section is drawn out while solidifying it. In the method, a second cooling means 9 (the graphite die is partially cooled) which is separate from the water cooling jacket is applied to uniformize the cooling of the deformed inner hole peripheral surface part of the graphite die, another second cooling means (injecting the air or the misty water) is applied to uniformize the temperature of the outer periphery of the cast iron bar after drawing out from the graphite die or both second cooling means are applied. The method can continuously cast the modified profile sectional cast iron bar with good quality. In the apparatus, a cooling medium passage 10 is buried in the graphite die as the second cooling means or alternatively, the air or water injecting nozzle injecting the air or the water toward the outlet of the graphite die is arranged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for continuously casting an irregular cross-section cast iron bar and an apparatus for carrying out the method.

  Conventionally, a cast iron round bar, a polygonal cross-section bar, and the like are manufactured by a continuous casting method advantageous in terms of manufacturing cost and uniform quality. The outline of the production is as follows. That is, the cast iron melt is accommodated in the tundish, a graphite die is arranged at the outlet of the melt provided in the tundish, the outer periphery of the die is cooled with a water cooling jacket, and the melt flowing out of the tundish is At least the entire outer peripheral portion is solidified while passing through the die, and the solidified cast iron bar on the outer periphery is solidified to the core portion while being moved so as to be pulled out by the moving feeding means.

  The die usually has a cylindrical outer shape, and a hole corresponding to a cross-sectional shape perpendicular to the axis of the cast iron rod is formed in the core in the axial direction, and the water-cooling jacket is in contact with the outer periphery of the die. It is formed by an inner wall having an inner peripheral surface, an outer wall that is coaxially arranged with a space therebetween, and both end walls that close a gap between both ends of the inner and outer walls, and circulates water as a refrigerant in the inside. The doorway is in place.

  Use conventional casting techniques such as conventional round bars and polygonal cross-section bars to cast irregular cross-section bars, such as chevron and groove cross-section bars found in rolled steel Then, the temperature at which the bar is cooled at different positions in the circumferential direction in the cross section becomes non-uniform, and stable casting cannot be performed, resulting in problems such as surface cracks and breakout. That is, it has been difficult to obtain a cast iron bar having an irregular cross section by continuous casting.

In order to improve the point at which the cooled temperature of the bar becomes non-uniform at different positions in the circumferential direction in the cross section, the distance from the outer peripheral surface of the graphite die to the inner hole is made substantially uniform over the entire outer peripheral portion to perform water cooling. It is conceivable to equalize the entire circumference, but for this purpose, the inner wall shape of the water-cooled jacket must be aligned with the shape of the outer peripheral surface of the die, and if the cross-sectional shape of the cast iron bar is different, not only the die but also the water-cooled jacket Another problem that must be prepared arises. Also, depending on the irregular cross-sectional shape of the cast iron rod, it is difficult to obtain uniformity in the outer peripheral surface temperature of the cast iron rod by simply cooling the entire circumference of the die bore, and the temperature at which the bar is cooled at different positions in the circumferential direction in the cross section There is also a problem that does not solve the problem of non-uniformity.
It is an object of the present invention to provide a continuously-shaped deformed cross-section cast iron bar and a method and apparatus capable of continuously casting the same.

  According to the first aspect of the present invention, the die has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water cooling jacket is disposed around the die, the die is cooled, and the molten cast iron flows into the die. In the continuous casting method of the deformed cross-section cast iron bar that is pulled out while solidifying, the second cooling means different from the water cooling jacket is applied to the die to equalize the cooling of the peripheral surface portion of the deformed inner hole of the die. (Claim 1).

  In this means, the temperature of the peripheral surface portion of the deformed cross-section cast iron rod drawn out can be equalized by compensating for insufficient cooling by the water-cooling jacket of the peripheral surface portion of the deformed inner hole of the die by another second cooling means. Defects in the deformed section cast iron bar can be reduced and breakout can be prevented.

  According to a second aspect of the present invention, the die has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water cooling jacket is disposed around the die to cool the die, and the molten cast iron flows into the die. In the continuous casting method of a deformed cross-section cast iron rod that is pulled out while being solidified, by injecting one or both of compressed air and mist-like water to the high temperature portion of the outer peripheral surface of the cross-section cast iron rod drawn out from the die The cooling state of the outer peripheral surface of the deformed cross-section cast iron rod is equalized (claim 2).

  In this means, the desired portion can be intensively cooled by jetting compressed air or mist-like water or both, so that the high-temperature portion of the deformed section cast iron rod drawn out from the die is grasped in advance. By appropriately cooling the portion, the temperature of the peripheral surface portion of the drawn out deformed section cast iron rod can be equalized over the entire circumference, so that defects in the deformed section cast iron rod continuously cast can be reduced and breakout can be prevented.

  According to a third aspect of the present invention, the die has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water cooling jacket is disposed around the die, the die is cooled, and the molten cast iron flows into the die. In a continuous casting apparatus for deformed section cast iron rods that are pulled out while being solidified, cooling is performed in the die so that the temperature of the outer surface of the deformed section cast iron rod cooled by the inner periphery of the deformed section of the die is equalized over the entire circumference. A medium passage is provided (claim 3).

  In this means, the temperature of the outer peripheral surface portion of the deformed cross-section cast iron rod to be cooled is equalized by providing a cooling medium passage in the die, so that the outer peripheral shape of the die can be made into a predetermined shape with almost no restraint. For example, it can be a shape corresponding to the inner shape of an existing water cooling jacket, even if the inner hole shape of the die is different, the outer periphery can be shared with the same predetermined shape, and the outer diameter of the die is stepwise If the predetermined size is determined, it can be handled by several types of water-cooled jackets. In this way, the type of the water cooling jacket can be reduced rather than the configuration in which the outer peripheral shape of the die is formed so as to correspond to the irregular cross section of the inner hole and the temperature is equalized, which is advantageous in terms of equipment costs. In addition, since the circulation amount of the refrigerant can be changed independently, temperature control can be relatively easily performed. Therefore, defects in the cast product can be reliably reduced, and breakout can be prevented.

  According to a fourth aspect of the present invention, the die has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water cooling jacket is disposed around the die to cool the die, and the molten cast iron flows into the die. One or both of an air injection nozzle and a mist injection nozzle arranged in the high temperature portion of the outer periphery of the deformed cross-section cast iron rod drawn out from the outlet of the die in the continuous casting apparatus of the deformed cross-section cast iron rod that is pulled out while being solidified (Claim 4).

  In this means, since the high temperature portion of the outer peripheral surface of the deformed cross-section cast iron rod immediately after being drawn from the die is cooled, the outer peripheral surface temperature is equalized, so that cracking is suppressed and reheating from the unsolidified portion in the center portion is performed. Breakout that occurs at is prevented. Moreover, it can implement easily only by using the existing cast iron rod continuous casting apparatus, and newly providing the die | dye and the injection nozzle of air or water.

  According to a fifth aspect of the present invention, the deformed cross-section cast iron rod has an inner hole corresponding to the cross-sectional shape perpendicular to the axis of the deformed cross-section cast iron rod, and a water cooling jacket is disposed around the die to cool the die, and In addition to the water-cooling jacket, a second cooling means for equalizing the cooling of the inner peripheral surface portion of the die is applied, and the cast die is formed by continuous casting which is poured into the die while being cast and solidified ( Claim 5). This modified cross-section cast iron bar is of high quality and low cost.

  According to a sixth aspect of the present invention, the deformed cross-section cast iron bar has an inner hole corresponding to the cross-sectional shape perpendicular to the axis of the deformed cross-section cast iron rod, and a water cooling jacket is disposed around the die to cool the die. Continuously equalize the cooling state of the outer peripheral surface by injecting one or both of compressed air and mist-like water to the high temperature portion of the outer peripheral surface of the deformed cross-section cast iron rod drawn out while allowing molten cast iron to flow into It is formed by casting (claim 6). This modified cross-section cast iron bar is of high quality and low cost.

The invention according to claim 1 has an effect of continuously casting a deformed cross-section cast iron bar with few casting defects without causing breakout.
The invention according to claim 2 has an effect of continuously casting an irregular cross-section cast iron bar with few casting defects without causing breakout.
The invention according to claim 3 is a new device capable of continuously casting a high-quality deformed cross-section cast iron rod so that breakout does not occur, and supplying refrigerant to the graphite die and its refrigerant passage in an existing cast iron rod continuous casting apparatus. There is an effect that can be easily implemented simply by providing it on the screen.
The invention according to claim 4 can continuously cast a high-quality deformed cross-section cast iron bar so that breakout does not occur, and newly adds a graphite die and an air or water injection nozzle in an existing cast iron bar continuous casting apparatus. The effect which can be easily implemented only by providing is produced.
The inventions according to claims 1 to 4 have an effect of providing a high-quality deformed cross-section cast iron bar at a low cost.
The inventions according to claim 5 and claim 6 have the effect that a high-quality deformed cross-section cast iron bar is inexpensive.

  In the method for continuously casting a deformed section cast iron rod, the die has a deformed inner hole corresponding to the deformed section shape of the cast product, a water cooling jacket is disposed around the die, the die is cooled, and the cast iron molten metal is placed on the die. In the continuous casting method, the second cooling means different from the water-cooling jacket is applied to the die to equalize the cooling of the peripheral surface portion of the deformed inner hole of the die, and the deformed cross section drawn from the die By injecting one or both of compressed air and mist-like water to the high temperature portion of the outer peripheral surface of the cast iron rod, the cooling state of the outer peripheral surface of the deformed cross-section cast iron rod is equalized.

  In the continuous casting apparatus for deformed section cast iron rod, the die has a deformed inner hole corresponding to the deformed section shape of the cast product, a water cooling jacket is arranged around the die, the die is cooled, and the cast iron melt is poured into the die. In a continuous casting apparatus that draws out while solidifying by flowing in, the passage of the cooling medium is provided in the die so that the temperature of the outer peripheral surface portion of the deformed section cast iron rod cooled by the inner peripheral portion of the deformed section of the die is equalized over the entire circumference. There is provided one or both of an air injection nozzle and a mist injection nozzle arranged to be directed to a high temperature portion of the outer periphery of the deformed cross-section cast iron rod drawn out from the outlet of the die.

  A deformed cross-section cast iron bar is a cast iron bar material that is produced by applying the method of the present invention or using the apparatus of the present invention to the one that has been cast by the sand because it cannot be obtained by the conventional continuous casting method. .

  A first embodiment of the present invention will be described with reference to FIGS. This embodiment is an apparatus used for carrying out a continuous casting method of a deformed section cast iron bar in which another second cooling means is applied to a die portion in addition to a water cooling jacket. 1 shows a schematic configuration of the apparatus, and a die made of a heat-resistant material, for example, a graphite die 4 and a water cooling jacket 5 is provided at the outlet 3 of the cast iron melt 2 accommodated in the tundish 1, and extends along the extension line of the outlet 3. A support roller 6 and a drawing movement device 7 are provided, and the graphite die 4 is provided with a modified cross-section inner hole 8 corresponding to a deformed cross-section cast iron rod of the product. As another second cooling means 9, for example, a cooling pipe 10 is connected to the graphite die. This is a configuration embedded in 4. The water cooling jacket 5 has an inlet 15 and an outlet 16 for cooling water. In this configuration, except for the modified cross-section inner hole 8 of the graphite die 4 and another second cooling means 9, it is almost the same as the conventional apparatus.

  The graphite die 4 has a rectangular cross section with an outer shape as shown in FIG. 3, and has a predetermined length in which an inner hole 8 having a deformed cross section corresponding to the cross sectional shape of the product is formed at the center. A water cooling jacket 5 is provided so that the inner peripheral surface is in contact with the entire outer periphery of the graphite die 4. The deformed cross-section cast iron rod 11 has, for example, a cross-section as shown in FIG. 2, and one of the long sides of the rectangle protrudes into a convex arc shape and the other is recessed into a concave arc shape. As shown in FIG. 1 and FIG. 3, another second cooling means 9 has a cooling pipe 10 embedded in a thick portion 12 formed by providing a deformed cross-section inner hole 8 of the graphite die 4. Water is circulated as the refrigerant through the inlet 13 and the outlet 14 shown in FIG. Therefore, the cooling capacity can be adjusted by adjusting the amount of water flow. Without the second cooling means 9, the thick portion 12 has a long heat transfer distance, so that the inside thereof becomes insufficiently cooled, but this can be solved by providing the second cooling means 9. The position, quantity, size, and the like of the illustrated cooling pipe 10 are conceptual and are appropriately determined at the design stage.

  In this embodiment, by providing the second cooling means 9, the temperature of the entire peripheral surface of the deformed cross-section cast iron rod 11 drawn from the graphite die 4 is equalized by cooling with the water cooling jacket 5 and the second cooling means 9. can do. That is, the shortage of cooling by the normal surrounding-type water-cooling jacket 5 is compensated by the second cooling means 9 so as to be equalized on the entire circumferential surface of the drawn out cross-section cast iron rod 11. Therefore, the irregular cross-section cast iron rod 11 can be continuously cast without defects so that breakout does not occur.

  A second embodiment of the present invention will be described with reference to FIG. This embodiment is an apparatus used for carrying out a continuous manufacturing method of a deformed cross-section cast iron bar in which another second cooling means is applied to a portion where the graphite die 4a is exited. FIG. 4 shows the schematic configuration of the apparatus. The main difference from the first embodiment is that another second cooling means 9 a is provided in place of the second cooling means 9. In FIG. 4, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. As shown in FIG. 4, the second cooling means 9 a is provided with the nozzle 20 facing the nozzle 20 at a higher temperature than the other parts around the entire circumference of the deformed cross-section cast iron rod 11 immediately after being drawn from the graphite die 4 a. The water is jetted as air is jetted from the nozzle 20. That is, air and mist are jetted onto the deformed cross-section cast iron rod 11. The relatively high-temperature portion of the deformed cross-section cast iron rod 11 is a portion in contact with the thick portion 12 of the graphite die 4a, and is the lower portion in FIG. The second cooling means 9a can adjust the cooling capacity by adjusting the supply amounts of water and air.

  In this embodiment, by providing the second cooling means 9a, the high temperature portion of the deformed cross-section cast iron rod 11 drawn out from the graphite die 4a is intensively cooled, and the temperature of the outer peripheral surface is equalized near the outlet. . Therefore, the deformed cross-section cast iron bar 11 can be obtained without deterioration of quality so that breakout does not occur.

In the third embodiment, although not shown, the second cooling means 9 and the second cooling means 9a in the second embodiment are used together in the first embodiment.
Thereby, when the surface temperature uniformity of the whole periphery of the deformed cross-section cast iron rod 11 is not good at the position where the graphite die 4 is left, the second cooling means 9a can be used to correct this. Moreover, after leaving the graphite die 4, the second cooling means 9a can be applied to a portion where the surface temperature is likely to rise due to the heat held inside. Therefore, since the outer peripheral surface temperature is further equalized, cracking is suppressed, and breakout caused by reheating from the unsolidified portion at the center is reliably prevented.

  In the above-described embodiment, the deformed cross-section cast iron rod 11 having a cross-sectional shape is shown in FIG. 2 as an example, but there are other cast iron bars having various cross-sections to be continuously cast according to the present invention. An example is shown in FIG. 5 (a) to 5 (d) show different graphite dies 40a to 40d, respectively, and different positions of the inner holes 41a to 41d and the approximate positions of the refrigerant passages 42a to 42d as the second cooling means 9, respectively. It is shown.

It is a vertical side view which shows typically the apparatus of 1st Example of this invention. It is an axial orthogonal cross-sectional enlarged view of the deformed cross-section cast iron bar exemplified in the embodiment. It is a cross-sectional enlarged view of the water cooling jacket and graphite die of the same Example. It is a vertical side view which shows typically the apparatus of 2nd Example of this invention. The cross-sectional shape of the deformed cross-section cast iron rod to which the present invention is applied is indicated by the inner hole of the graphite die, and (a) to (d) are cross-sectional views of different graphite dies.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tundish 2 Cast iron molten metal 3 Outlet 4, 4a Graphite die 5 Water-cooling jacket 6 Support roller 7 Drawing movement apparatus 8 Deformed cross-section inner hole 9, 9a Second cooling means 10 Cooling pipe 11 Deformed cross-section cast iron rod 12 Thick part 13 Inlet 14 Outlet 20 Nozzle 40a to 40d Graphite die 41a to 41d Modified cross-section inner hole 42a to 42d Refrigerant passage

Claims (6)

A deformed cross-section cast iron that has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water-cooled jacket is disposed around the die, cools the die, and draws the molten cast iron into the die while solidifying it. In the continuous casting method of a rod, the second cooling means different from the water-cooling jacket is applied to the die to equalize the cooling of the peripheral surface portion of the modified inner hole of the die, and the continuous casting method of the deformed section cast iron rod . A deformed cross-section cast iron that has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water-cooled jacket is disposed around the die, cools the die, and draws the molten cast iron into the die while solidifying it. In the rod continuous casting method, the outer peripheral surface of the deformed cross-section cast iron bar is cooled by injecting one or both of compressed air and mist-like water onto the high temperature portion of the outer peripheral surface of the deformed cross-section cast iron rod drawn from the die. A method for continuously casting a deformed cross-section cast iron bar characterized in that A deformed cross-section cast iron that has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water-cooled jacket is disposed around the die, cools the die, and draws the molten cast iron into the die while solidifying it. In the continuous casting apparatus for a rod, a cooling medium passage is provided in the die so that the temperature of the outer peripheral surface portion of the deformed section cast iron rod cooled by the inner peripheral portion of the deformed section of the die is equalized over the entire circumference. A continuous casting machine for deformed section cast iron bars. A deformed cross-section cast iron that has a deformed inner hole corresponding to the deformed cross-sectional shape of the cast product, a water-cooled jacket is disposed around the die, cools the die, and draws the molten cast iron into the die while solidifying it. In the continuous casting apparatus for bars, one or both of an air injection nozzle and a mist injection nozzle arranged to be directed to the high temperature portion of the outer periphery of the deformed cross-section cast iron bar drawn from the outlet of the die are provided. Continuous casting equipment for cross-section cast iron bars. The die has an inner hole corresponding to a cross-sectional shape perpendicular to the axis of the deformed cross-section cast iron rod, and a water cooling jacket is disposed around the die to cool the die, and the inner hole peripheral surface portion of the die separately from the water cooling jacket A deformed cross-section cast iron bar formed by continuous casting using a second cooling means for equalizing the cooling of the steel and drawing the molten cast iron into the die and solidifying it. The die has an inner hole corresponding to a cross-sectional shape perpendicular to the axis of the deformed cross-section cast iron rod, a water cooling jacket is arranged around the die, the die is cooled, and the cast iron melt is poured into the die to be solidified and drawn out. A modified cross-section cast iron rod formed by continuous casting that equalizes the cooling state of the outer peripheral surface by injecting one or both of compressed air and mist-like water onto the high temperature portion of the outer surface of the deformed cross-section cast iron rod.

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