Design method for narrow-edge copper plate of nearly-square small-chamfer crystallizer

Abstract

The invention relates to the technical field of metallurgical chamfering crystallizers, and particularly discloses a design method for a narrow-edge copper plate of an approximately-square small-chamfering crystallizer, which comprises the following steps: S1, the width of a chamfering surface of the narrow-edge copper plate of the chamfering crystallizer is 17-23 mm; s2, no plating is carried out on the chamfering surface of the narrow-edge copper plate of the chamfering crystallizer within the range of 200mm away from an upper opening; s3, water seams on the two sides of the bolt at the position 50-150 mm away from the upper opening of the wide-edge copper plate of the chamfering crystallizer are communicated through crossed water seals; the shape chamfer of the crystallizer designed by the invention is smaller and closer to a square, the corner crack of the continuous casting billet can be eliminated, and the rolling edge black line and hairline defects can be reduced; the upper part of the chamfering surface is not provided with a plating layer, so that the cooling strength is higher, the throwing speed is not limited by chamfering, and longitudinal cracks at the corner of the continuous casting billet are reduced; water seams on the two sides of bolts in the area, 50-150 mm away from an upper opening, of the wide-edge copper plate of the chamfering crystallizer are communicated through crossed water seals, and cooling is more uniform.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical chamfered mold, and particularly relates to a design method for the narrow-side copper plate of a near-square small-chamfered mold. Background Art

[0002] The principle of the chamfered mold is to change the structure of the narrow-side copper plate of the mold, adding an obtuse chamfer on both sides of the narrow-side copper plate, so that the two-dimensional cooling at the original right-angle position of the edge becomes nearly one-dimensional cooling, thereby delaying the cooling of the corner of the slab, increasing the temperature of the corner of the slab. At the same time, compared with the slab produced by the conventional mold, the chamfered mold can effectively relieve the stress concentration problem at the corner during the continuous casting process, and has an advantage in physical structure for controlling transverse cracks at the corner. The chamfered mold has been widely used in domestic continuous casting machines and plays a great role in solving the corner cracks of thick-specification medium-carbon high-manganese steel grades and plain carbon steel slabs. However, it does not improve or even increases defects such as black lines and hair cracks on the edges of pipeline steel, and there is also a problem of restricting the casting speed of the continuous casting machine.

[0003] Inventing a mold that can not only improve the corner cracks of the slab but also inhibit defects such as black lines and hair cracks on the rolled edges and does not restrict the casting speed is of great significance for improving the quality of the slab in the steel mill. Therefore, a design method for the narrow-side copper plate of a near-square small-chamfered mold is needed to solve the problems of black lines and hair cracks on the edges of existing pipeline steel. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a design method for the narrow-side copper plate of a near-square small-chamfered mold.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a design method for the narrow-side copper plate of a near-square small-chamfered mold, including the following steps:

[0006] S1. The width of the chamfered surface of the narrow-side copper plate of the chamfered mold is 17 - 23 mm;

[0007] S2. There is no plating within 200 mm from the upper opening at the chamfered surface of the narrow-side copper plate of the chamfered mold;

[0008] S3. Connect the water gaps on both sides of the bolts at 50 - 150 mm from the upper opening of the wide-side copper plate of the chamfered mold with a cross-shaped water seal.

[0009] Specifically, the width of the chamfered surface of the narrow-side copper plate of the chamfered mold in step S1 is less than the narrow-side width of the chamfered mold that has been applied, and the shape of the chamfered surface of the narrow-side copper plate of the chamfered mold is near-square.

[0010] Specifically, the shape of the chamfered surface of the narrow-side copper plate of the chamfered mold is designed to be near-square, so that the high-temperature molten steel solidifies into a small-chamfered slab closer to a square at this position during application.

[0011] Specifically, within a range of 200 mm from the upper opening at the chamfered surface in step S2, no plating is applied to reduce the thermal resistance of the chamfered surface of the narrow-side copper plate.

[0012] Specifically, at positions 50 - 150 mm from the upper part where the intervals between each pair of bolts on the wide-side copper plate of the chamfered mold are relatively large in step S3, two intersecting inclined water slots are arranged. The inclined water slots are connected to the water slots on both sides of the bolts to control the cooling water to pass through the area with relatively large bolt intervals, thereby uniformly cooling the chamfered surface of the chamfered mold.

[0013] The present invention has the following beneficial effects:

[0014] The design method of the narrow-side copper plate of the nearly square small-chamfer mold designed by the present invention has a smaller chamfer on the mold shape and is closer to a square. The continuous casting billet can not only eliminate corner cracks but also reduce the black lines and hair cracks on the rolled edge.

[0015] The design method of the narrow-side copper plate of the nearly square small-chamfer mold designed by the present invention has no plating on the upper part of the chamfered surface, with greater cooling intensity. The billet drawing speed is not restricted by the chamfer, reducing the generation of longitudinal cracks at the corners of the continuous casting billet.

[0016] The design method of the narrow-side copper plate of the nearly square small-chamfer mold designed by the present invention has the water slots on both sides of the bolts in the area 50 - 150 mm from the upper opening of the wide-side copper plate of the chamfered mold (this area has the greatest influence on the surface quality of the continuous casting billet) connected by intersecting water seals, resulting in more uniform cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the lower opening of the narrow-side copper plate of the nearly square small-chamfer mold.

[0018] Figure 2 It is a schematic structural diagram of the narrow-side copper plate of the nearly square small-chamfer mold with intersecting inclined water slots provided.

[0019] Figure 3 It is a physical diagram of the continuous casting billet after the application of the narrow-side copper plate of the nearly square small-chamfer mold.

[0020] Figure 4 It is a physical diagram of the narrow-side copper plate of the nearly square small-chamfer mold without plating. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following will further clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] In view of the defects existing in the large chamfer mold, the present invention invents a near-square small chamfer mold copper plate. The following technical solutions are provided:

[0023] 1. The lower opening of the narrow-side copper plate of the near-square small chamfer mold of the present invention is as Figure 1 shown. The chamfer surface width of the narrow-side copper plate of the near-square small chamfer mold of the present invention (as Figure 1 shown) is 17 - 23 mm. This chamfer surface width is much smaller than that of the narrow side of the chamfer mold currently in use, and has the characteristic of being closer to a square in shape. This shape design enables the high-temperature molten steel to solidify into a small chamfer-shaped billet closer to a square at this position during application. The continuous casting billet can not only eliminate corner cracks but also reduce the edge folding of the chamfer surface during the rolling process.

[0024] The physical chamfer photo of the continuous casting billet after the application of the narrow-side copper plate of the near-square small chamfer mold is as Figure 3 shown. The chamfer of the mold shape is smaller and closer to a square. The continuous casting billet can not only eliminate corner cracks but also reduce the defects of black lines and hair cracks on the rolled edge.

[0025] 2. There is no plating within 200 mm from the upper opening at the chamfer surface of the narrow-side copper plate of the mold. The purpose of this design is to reduce the thermal resistance of the chamfer surface of the narrow-side copper plate and increase cooling. If plated, due to the relatively weak cooling intensity of the chamfer surface of the copper plate, longitudinal corner cracks will form in the continuous casting billet at this position; without plating, the cooling intensity is effectively increased, preventing the generation of longitudinal corner cracks. The physical near-square small chamfer narrow-side copper plate without plating is as Figure 4 shown. There is no plating on the upper part of the chamfer surface, and the cooling intensity is greater. The billet withdrawal speed is not restricted by the chamfer, and the generation of longitudinal corner cracks in the continuous casting billet can be reduced.

[0026] 3. Connect the water gaps on both sides of the bolts at 50 - 150 mm from the upper opening of the wide-side copper plate of the chamfer mold (this area has the greatest impact on the surface quality of the continuous casting billet) with crossed water seals. At each position where the interval between bolts of the wide-side copper plate of the near-square small chamfer mold is relatively large, two crossed inclined water gaps are arranged at a position 50 - 150 mm from the upper part. The inclined water gaps connect the water gaps on both sides of the bolts, allowing the cooling water to pass through the area with a relatively large bolt interval, thereby uniformly cooling the chamfer surface of the chamfer mold and preventing the generation of defects such as longitudinal corner cracks in the casting billet. The water gap arrangement of the wide-side copper plate of the chamfer mold of the present invention is as Figure 2 shown, and the newly opened water gaps are marked in red, connecting the water gaps on both sides of the bolts.

[0027] The present invention is not limited to the above embodiments. Anyone should know that structural changes made under the inspiration of the present invention, as long as they have the same or similar technical solutions as the present invention, fall within the protection scope of the present invention.

[0028] The technologies, shapes, and structures not described in detail in the present invention are all well-known technologies.

Claims

1. A design method for the narrow-side copper plate of a nearly square small-chamfer mold, characterized in that It includes the following steps: S1. The width of the chamfered surface of the narrow-side copper plate of the chamfered mold is 17 - 23 mm; S2. No plating is carried out within the range of 200 mm from the upper opening at the chamfered surface of the narrow-side copper plate of the chamfered mold; S3. The water seams on both sides of the bolts at the position 50 - 150 mm from the upper opening of the wide-side copper plate of the chamfered mold are connected by cross water seals.

2. The design method of the narrow-side copper plate of the nearly square small chamfer mold according to claim 1, characterized in that, The width of the chamfered surface of the narrow-side copper plate of the chamfered mold in step S1 is smaller than the width of the narrow side of the chamfered mold that has been applied, and the shape of the chamfered surface of the narrow-side copper plate of the chamfered mold is nearly square.

3. The design method of the narrow-side copper plate of the near-square small-chamfered mold according to claim 2, characterized in that, The shape of the chamfered surface of the narrow-side copper plate of the chamfered mold being nearly square is designed so that when in use, the high-temperature molten steel solidifies into a small chamfered billet that is closer to a square at this place.

4. The design method of the narrow-side copper plate of the near-square small-chamfered mold according to claim 1, characterized in that, Not plating within the range of 200 mm from the upper opening at the chamfered surface in step S2 reduces the thermal resistance of the chamfered surface of the narrow-side copper plate.

5. The design method of the narrow-side copper plate of the nearly square small chamfer mold according to claim 1, characterized in that At the position 50 - 150 mm from the upper part where the interval between each bolt on the wide-side copper plate of the chamfered mold in step S3 is relatively large, two cross inclined water seams are arranged. The inclined water seams connect the water seams on both sides of the bolts to control the cooling water to pass through the area with a relatively large bolt interval, thereby uniformly cooling the chamfered surface of the chamfered mold.

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