Manufacturing method for steel ingot

Abstract

To provide a manufacturing method for readily obtaining a steel ingot.SOLUTION: The manufacturing method for a steel ingot includes: A: a process for injecting molten steel into a first cavity and a second cavity of a mold 2; B: a process for cooling this molten steel to obtain a first solidified portion 22a and a second solidified portion 22b; C: a process for dropping this mold 2, first solidified portion 22a, and second solidified portion 22b; D: a process for pushing the first solidified portion 22a with a first push 20a to separate it from the inner surface of the first cavity, and pushing the second solidified portion 22b with a second push 20b shorter than the first push 20a to separate it from the inner surface of the second cavity; D: a process for removing the first solidified portion 22a from the mold 2; and E: a process for removing the second solidified portion 22b from the mold 2.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] This specification discloses a method for producing a steel ingot. In particular, this specification discloses an improved method for demolding a steel ingot from a mold. [Background technology]

[0002] In steelmaking plants, molten steel is obtained through refining in converters, electric furnaces, etc. This molten steel is poured into a mold and cooled to obtain an ingot. The ingot is then removed from the mold. An example of a method for demolding an ingot is disclosed in Japanese Utility Model Laid-Open Publication No. 62-72761. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 62-72761 Summary of the Invention [Problem to be solved by the invention]

[0004] The demolding method disclosed in Japanese Utility Model Laid-Open Publication No. 62-72761 requires large-scale equipment and imposes a heavy burden on the worker.

[0005] The present applicant intends to provide a manufacturing method by which steel ingots can be obtained easily. [Means for solving the problem]

[0006] The method for producing a steel ingot disclosed in the present specification includes the steps of: (1) pouring molten steel into a mold cavity; (2) a step of cooling the molten steel to obtain a solidified product; (3) a step of dropping the mold and the solidified material toward a demolding device including a push, causing the solidified material to collide with the push; (4) a step of poking the solidified material with the push to cause the upper end of the solidified material to protrude from the mold; and (5) Removing the solidified material from the mold Preferably, the mold is dropped a distance of 300 mm or more and 1500 mm or less in the step (3).

[0007] The method for producing a steel material disclosed in this specification includes: (1) pouring molten steel into a mold cavity; (2) a step of cooling the molten steel to obtain a solidified product; (3) a step of dropping the mold and the solidified material toward a demolding device including a push, causing the solidified material to collide with the push; (4) a step of poking the solidified material with the push to cause the upper end of the solidified material to protrude from the mold; (5) removing the solidified material from the mold to obtain a steel ingot; and (6) A process of subjecting the steel ingot to plastic processing Includes.

[0008] Another method for producing a steel ingot disclosed in the present specification includes: A: A step of pouring molten steel into a first cavity and a second cavity of a mold; B: A step of cooling the molten steel to obtain a first solidified product and a second solidified product; C: dropping the mold, the first coagulated material, and the second coagulated material toward a demolding device including a first push and a second push having a height smaller than that of the first push, causing the first coagulated material to collide with the first push and the second coagulated material to collide with the second push; D: a step of thrusting the first coagulated material with a first push and thrusting the second coagulated material with the second push to cause the upper ends of the first coagulated material and the second coagulated material to protrude from the mold; E: removing the first solidified material from the mold; and F: Step of removing the second solidified material from the mold Preferably, the fall distance of the mold in step C is 300 mm or more and 1500 mm or less. Preferably, in step C, the mold, the first solidified product, and the second solidified product are dropped toward a demolding device in which the difference (H1-H2) between the height H1 of the first push and the height H2 of the second push is 100 mm or more. [Effects of the Invention]

[0009] This manufacturing method does not require large-scale equipment, imposes a small burden on workers, and can produce steel ingots at low cost. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a flowchart showing a method for producing a steel ingot according to one embodiment. [Figure 2] FIG. 2 is a perspective view showing a mold used in the manufacturing method of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a perspective view showing a demolding device used in the manufacturing method of FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing one step of the manufacturing method of FIG. [Figure 7] FIG. 7 is a cross-sectional view showing another step of the manufacturing method of FIG. [Figure 8] FIG. 8 is a cross-sectional view showing still another step of the manufacturing method of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, preferred embodiments will be described in detail with reference to the drawings as appropriate.

[0012] 2 and 3 show a mold 2. This mold 2 has a body 4, a first cavity 6a, a second cavity 6b, and a plurality of hands 8. The first cavity 6a penetrates the body 4 in the vertical direction of FIG. 3. The first cavity 6a has an upper opening 10a and a lower opening 12a. The second cavity 6b also penetrates the body 4 in the vertical direction of FIG. 3. The second cavity 6b has an upper opening 10b and a lower opening 12b. In this embodiment, the shape and size of the second cavity 6b are the same as those of the first cavity 6a. Each hand 8 is joined to the body 4.

[0013] 4 and 5 show the demolding device 14. The demolding device 14 has a base 16, a plurality of guide bars 18, a first push 20a, and a second push 20b. Each guide bar 18 stands upright from the base 16. The guide bars 18 are fixed to the base 16.

[0014] The first pusher 20a stands upright from the base 16. The first pusher 20a is fixed to the base 16. In this embodiment, the first pusher 20a has a cylindrical shape. The first pusher 20a may have a rectangular pillar shape. The first pusher 20a may have a block shape. The first pusher 20a has a height H1.

[0015] The second pusher 20b stands upright from the base 16. The second pusher 20b is fixed to the base 16. In this embodiment, the second pusher 20b has a cylindrical shape. The second pusher 20b may have a prismatic shape. The second pusher 20b may have a block shape. The second pusher 20b has a height H2. The height H2 of the second pusher 20b is smaller than the height H1 of the first pusher 20a.

[0016] In a steel ingot manufacturing method using this demolding apparatus 14, molten steel is prepared through refining and the like (STEP 1). This molten steel is poured into the first cavity 6a and the second cavity 6b (STEP 2). This process is called pouring.

[0017] The molten steel is cooled in the cavity 6 (STEP 3). The molten steel solidifies by cooling, and a solidified product 22 (see FIG. 6) is obtained. A first solidified product 22a is obtained in the first cavity 6a. A second solidified product 22b is obtained in the second cavity 6b. In this embodiment, the shape and size of the second solidified product 22b are the same as those of the first solidified product 22a.

[0018] The mold 2 is transported onto the demolding device 14 (STEP 4). This transportation can be achieved by a tong crane gripping the short sides of the mold 2. Since the first solidified material 22a and the second solidified material 22b are filled in the cavity 6, these solidified materials 22 are also transported together with the mold 2. The mold 2 and demolding device 14 after movement are shown in FIG. 6.

[0019] The tong crane moves the mold 2 further downward (STEP 5). The guide bar 18 guides this movement. As the mold 2 moves, it is set in a predetermined position. The set mold 2 is shown in FIG. 7. In FIG. 7, the first solidified material 22a is located directly above the first push 20a, and the second solidified material 22b is located directly above the second push 20b.

[0020] The mold 2 is then dropped (STEP 6). This dropping is achieved by the crane releasing the mold 2. The mold 2 falls downward under its own weight. The guide bar 18 guides this drop.

[0021] As the solidified material 22 falls, it collides with the push 20 (STEP 7). Specifically, the lower surface of the first solidified material 22a collides with the upper surface of the first push 20a, and the lower surface of the second solidified material 22b collides with the upper surface of the second push 20b.

[0022] The impact force of the collision (STEP 7) causes demolding (STEP 8). Specifically, the first solidified material 22a separates from the inner surface of the first cavity 6a, and the second solidified material 22b separates from the inner surface of the second cavity 6b. The solidified material 22 after demolding is shown in FIG. 8. The solidified material 22 protrudes upward from the mold 2 and stands upright. As described above, height H1 is large and height H2 is small. Therefore, the first solidified material 22a protrudes significantly from the mold 2, and the second solidified material 22b protrudes slightly from the mold 2.

[0023] The first solidified material 22a is removed from the mold 2 to obtain a first steel ingot (STEP 9). This removal is achieved by grasping the first solidified material 22a with a tong crane or the like. The tong crane grasps the vicinity of the upper end of the first solidified material 22a. As described above, the second solidified material 22b protrudes slightly from the mold 2. Therefore, the tong crane can grasp the first solidified material 22a without interfering with the second solidified material 22b.

[0024] The second solidified product 22b is removed from the mold 2 to obtain a second steel ingot (STEP 10). This removal is achieved by grabbing the second solidified product 22b with a tong crane or the like.

[0025] These steel ingots are subjected to plastic working such as rolling to obtain steel products, typical of which are steel bars and steel wires.

[0026] By dropping (STEP 6), the mold 2 moves from the position shown in FIG. 7 to the position shown in FIG. 8. In FIG. 7, the arrow Lc indicates the drop distance of the mold 2. This distance Lc is preferably 300 mm or more and 1500 mm or less. Dropping with a distance Lc of 300 mm or more applies a sufficient impact force to the solidified material 22. From this viewpoint, the distance Lc is more preferably 500 mm or more, and particularly preferably 700 mm or more. Dropping with a distance Lc of 1500 mm or less can be performed using simple equipment. From this viewpoint, the distance Lc is more preferably 1200 mm or less, and particularly preferably 900 mm or less.

[0027] From the viewpoint of facilitating removal of the second solidified material 22b (STEP 10), the height H2 is preferably 100 mm or more, more preferably 200 mm or more, and particularly preferably 250 mm or more. From the viewpoint of preventing interference of the tong crane with the second solidified material 22b in removal of the first solidified material 22a (STEP 9), the difference (H1-H2) between the heights H1 and H2 is preferably 100 mm or more, more preferably 150 mm or more, and particularly preferably 200 mm or more. When the first solidified material 22a is removed by a method that does not require consideration of interference with the second solidified material 22b, the difference (H1-H2) may be zero.

[0028] When the number of cavities 6 is one and therefore the mold 2 containing one solidified material 22 is dropped, the number of pushers 20 in the demolding device 14 is sufficient to be one. The demolding device 14 may have three or more pushers 20. [Example]

[0029] Steel ingots were manufactured using the equipment shown in Figures 2-5. The drop distance Lc was 600 mm, the first push height H1 was 300 mm, and the second push height H2 was 200 mm. 120 steel ingots were obtained after 60 drops. The demolding success rate was 90%. The cycle time was 420 minutes, which was shorter than the 540 minutes required for conventional manufacturing methods.

[0030] Steel ingots were manufactured using the equipment shown in Figures 2-5. The drop distance Lc was 800 mm, the first push height H1 was 500 mm, and the second push height H2 was 300 mm. 120 steel ingots were obtained after 60 drops. The demolding success rate was 100%. The cycle time was 300 minutes. This cycle time was shorter than the 540 minutes of the conventional manufacturing method.

[0031] These evaluation results clearly demonstrate the superiority of this manufacturing method. [Industrial Applicability]

[0032] The manufacturing method described above is suitable for steel ingots of various steel grades. [Explanation of symbols]

[0033] 2. Mold 4. Body 6. Cavity 6a First cavity 6b...Second cavity 8 hands 14...Demolding equipment 16...Base 18 Guide bar 20 Push 20a First push 20b...Second push 22...coagulum 22a...first coagulation 22b...Second coagulum

Claims

1. (1) pouring molten steel into a mold cavity; (2) A step of cooling the molten steel to obtain a solidified product; (3) A step of dropping the mold and the solidified material toward a demolding device including a push, and causing the solidified material to collide with the push; (4) a step of poking the solidified material with the pusher to cause the upper end of the solidified material to protrude from the mold; and (5) A step of removing the solidified product from the mold. A method for manufacturing a steel ingot, comprising:

2. 2. The method according to claim 1, wherein the mold is dropped a distance of 300 mm or more and 1500 mm or less in the step (3).

3. (1) pouring molten steel into a mold cavity; (2) A step of cooling the molten steel to obtain a solidified product; (3) A step of dropping the mold and the solidified material toward a demolding device including a push, and causing the solidified material to collide with the push; (4) a step of poking the solidified material with the pusher to cause the upper end of the solidified material to protrude from the mold; (5) removing the solidified material from the mold to obtain a steel ingot; and (6) A step of subjecting the steel ingot to plastic working A method for manufacturing steel comprising the steps of:

4. A: A step of pouring molten steel into a first cavity and a second cavity of a mold; B: A step of cooling the molten steel to obtain a first solidified product and a second solidified product; C: dropping the mold, the first coagulated material, and the second coagulated material toward a demolding device including a first push and a second push having a height smaller than that of the first push, causing the first coagulated material to collide with the first push and the second coagulated material to collide with the second push; D: A step of poking the first coagulated material with a first push and poking the second coagulated material with the second push, thereby causing the upper ends of the first coagulated material and the second coagulated material to protrude from the mold; E: A step of removing the first solidified product from the mold. and F: Step of removing the second solidified material from the mold A method for manufacturing a steel ingot, comprising:

5. The method according to claim 4, wherein the mold is dropped a distance of 300 mm or more and 1500 mm or less in step C.

6. 6. The manufacturing method according to claim 4 or 5, wherein in the step C, the mold, the first solidified material, and the second solidified material are dropped toward the demolding device, the difference (H1-H2) between the height H1 of the first push and the height H2 of the second push being 100 mm or more.

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