JP4203557B2 - Cast iron for producing continuous cast bar, method for producing continuous cast bar, and Zn wire or Zn-Al alloy wire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a casting rod used for producing a continuous casting bar by pouring molten metal into a rotary strip casting machine, a method for producing a continuous casting bar using the casting rod, and a continuous casting produced by the production method. The present invention relates to a metal wire manufactured by rolling a bar.
[0002]
[Prior art]
Conventionally, for example, in the production of Zn-Al alloy wire, after producing a Zn-Al alloy bar by die casting or semi-continuous casting, it is hot-worked by a hot groove roll rolling method or a hot extrusion method, and then cold-worked. A batch type processing method (JP-A-6-228686, JP-A-11-181562) finished by processing, a continuous casting rolling method (for example, Patent Document 1) in which a rotary strip casting machine and a continuous rolling machine are combined, and the like have been used.
[0003]
The above continuous casting and rolling method is a method with excellent productivity capable of continuously producing the above-described Zn—Al alloy wire, Zn wire, Cu wire, Cu alloy wire, and the like. This continuous casting and rolling method will be briefly described with reference to the drawings, taking as an example the production of a Zn-Al alloy wire.
FIG. 4 is a schematic cross-sectional view of a manufacturing process in a continuous casting and rolling method using a rotary strip casting machine.
In FIG. 4, the manufacturing process includes a molten metal furnace 1, a rotary strip casting machine 2, and a continuous rolling mill 9.
The molten metal furnace 1 includes a furnace body 11 and a nozzle rod 4, and a heating device (not shown) is installed on the outer periphery of the furnace body 11.
The rotary strip casting machine 2 is adjacent to the casting wheel 21, rolls 22, 23, 24 and the steel strip 25 rotating between these wheels and the roll, and the cooling water jet device 26 and the rotary strip casting machine 2 in the casting wheel. The cooling water injection device 27 is configured.
[0004]
Next, the production of the Zn—Al alloy wire by the production process will be briefly described.
A predetermined amount of the molten Zn—Al alloy in the molten metal furnace maintained at a predetermined temperature is supplied to the rotary strip casting machine 2 through the nozzle rod 4 every predetermined time. The supply amount is appropriately determined depending on the manufacturing process capacity of the subsequent process.
[0005]
A mold groove is cut in the center of the outer peripheral portion of the casting wheel 21 of the rotary strip casting machine 2, and the molten Zn—Al alloy supplied from the nozzle 4 is sandwiched between the mold groove and the steel strip 25. Further, it is cooled by the cooling water injection device 26 and manufactured to the continuous casting bar 5. The obtained continuous casting bar 5 is cooled by the cooling water injection device 27, controlled within an appropriate temperature range, and sent to the continuous rolling mill 9 in the next step.
The continuous casting bar 5 sent to the continuous rolling mill 9 can be rolled as desired to obtain a Zn—Al alloy wire.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-20826
[Problems to be solved by the invention]
However, in the continuous casting rolling method that combines the above-mentioned rotary strip casting machine and continuous rolling mill, a crack occurs in the continuous casting bar manufactured by the rotary strip casting machine, and the bar breaks in the continuous rolling mill in the next process. However, there are cases where a good metal wire such as a Zn—Al alloy wire cannot be produced.
[0008]
As a result of intensive studies by the inventors, the shape and structure of the metal pouring molten metal such as Zn-Al alloy into the rotary strip casting machine has an effect on the occurrence of cracks in continuous cast bars such as Zn-Al alloy. I thought of giving.
[0009]
Hereinafter, this elucidation process will be briefly described with reference to the drawings, taking as an example the production of a continuous cast bar of Zn-Al alloy. ,
FIG. 3 is an enlarged perspective view showing a state in which a nozzle rod according to the prior art is installed on a casting wheel of a rotary strip casting machine and molten metal is cast.
[0010]
In the rotary strip casting machine 2 shown in FIG. 3, reference numeral 21 denotes a casting wheel, and a casting groove 200 having a casting groove wall portion 220 and a casting groove bottom portion 230 is provided on the outer peripheral surface of the casting wheel 21. The surface constitutes the casting groove top 210.
In the casting groove 200, the nozzle rod 4 according to the conventional technique is installed, and the molten metal 3 is poured. A roll 22 is provided in contact with the casting wheel 21 at a point where the molten metal 3 is poured into the casting groove 200, and a steel strip 25 is provided on the roll 22.
[0011]
The molten metal 3 flowing down from the nozzle rod 4 according to the prior art is accommodated in the casting groove 200 and is continuously conveyed to the front side of the drawing by the rotation of the casting wheel 21 toward the front side of the drawing. It is sandwiched between the bands 25 and cast.
[0012]
When the molten metal 3 flows down from the nozzle trough 4 according to the prior art, the present inventors vigorously collide with the casting groove bottom 230 due to a large weight and bounce off, contain bubbles, generate oxides, disturb It has been found that casting is performed while reaching the position of the roll 22 while generating a flow and the like and sandwiched between the steel strip 25 and the casting groove 200. And this bounce, inclusion of bubbles, generation of oxides, generation of turbulent flow, etc. result in breaking the cooling balance of the molten metal 3 at the time of casting, and as a result, it causes cracks in the manufactured continuous casting bar. This was the cause of breakage of the bar in the continuous rolling mill in the next process.
[0013]
In view of the above-described elucidation results, the problem to be solved by the present invention is to generate cracks in a continuous casting bar that is a casting rod used when manufacturing a continuous casting bar using a rotary strip casting machine. It is providing the metal wire manufactured from the continuous casting bar manufactured by the manufacturing method of the continuous casting bar using the casting rod without this, the said casting rod, and the manufacturing method of the said continuous casting bar.
[0014]
[Means for Solving the Problems]
The first means is a casting rod used for producing a continuous casting bar by pouring molten metal into a rotary strip casting machine,
The molten metal that flows into the casting groove provided in the casting wheel of the rotary strip casting machine that is provided at the leading end of the runner and the runner through which the molten metal that has flowed out from the calming part passes, And a hot water outlet for pouring hot water,
The bottom of the runner is connected to the tap with a downward slope,
The bottom of the top end of the tap is located below the top of the casting groove, and is a casting rod for producing a continuous casting bar.
[0015]
By the above configuration, the height difference between the bottom of the runner and the casting groove bottom is stably shortened to a desired value, and the impact when the molten metal collides with the casting groove bottom is reduced. It can suppress that a crack generate | occur | produces in the manufactured continuous casting bar.
[0016]
The second means is a casting rod used when manufacturing the continuous cast bar described in the first means,
A cast iron for producing a continuous casting bar, wherein a difference in height between the bottom of the runner and the bottom of the casting groove is 10 mm or less.
[0017]
The height difference between the bottom of the runner and the bottom of the casting groove is preferably 10 mm or less.
[0018]
The third means is a casting rod used when producing the continuous cast bar according to the first or second means,
The continuous cast bar is a cast bar for producing a continuous cast bar, which is a bar of Zn or Zn-Al alloy.
[0019]
The cast iron having the above structure is suitable for producing a continuous cast bar of Zn or Zn-Al alloy.
[0020]
The fourth means is a manufacturing method for manufacturing a continuous casting bar using a rotary strip casting machine,
A continuous cast bar manufacturing method, wherein a continuous cast bar is manufactured using the casting rod for manufacturing a continuous cast bar according to any one of the first to third means.
[0021]
By using the casting rod having the above-described configuration, a continuous casting bar can be manufactured by a rotary strip casting machine, thereby suppressing the occurrence of cracks.
[0022]
The fifth means is the method for producing a continuous cast bar according to the fourth means,
In the continuous casting bar manufacturing method, the molten metal poured into the casting groove from the tip of the tap is in contact with the bottom of the casting groove at a position less than 20 mm from the tip of the tap. is there.
[0023]
When a continuous casting bar is manufactured by a rotary strip casting machine using the cast iron having the above-described configuration, the molten metal poured from the top of the tap into the casting groove is less than 20 mm from the tip of the tap. By making contact with the bottom of the casting groove at a position, it is possible to manufacture a continuous casting bar in which the generation of cracks is suppressed.
[0024]
A sixth means is a method for producing a continuous cast bar according to the fourth or fifth means,
The continuous cast bar is a method for producing a continuous cast bar, which is a bar of Zn or Zn—Al alloy.
[0025]
The method for producing a continuous cast bar having the above-described configuration is suitable for producing a continuous cast bar of Zn or Zn—Al alloy.
[0026]
A seventh means is a Zn wire or Zn-Al produced by rolling a Zn or Zn-Al alloy continuous cast bar produced by the method for producing a continuous cast bar according to the sixth means. Alloy wire.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the process of the present inventors and embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an improved cast iron according to the present invention installed on a casting wheel of a rotary strip casting machine, and FIG. 2 is a perspective view of the cast iron according to the intermediate stage of the present invention. It is the perspective view which showed the state installed in the casting wheel of the casting machine.
[0028]
When the molten metal flows down from the nozzle trough according to the prior art, the present inventors vigorously collide with the bottom of the casting groove due to the large weight, which is a cause of cracks in the manufactured continuous casting bar. Based on the elucidated results, a cast iron 300 according to the intermediate stage of the present invention shown in FIG. 2 was produced.
In FIG. 2, the nozzle rod 4, the casting wheel 21, the casting groove 200, the casting groove top portion 210, the casting groove wall portion 220, the casting groove bottom portion 230, the roll 22, and the steel strip 25 are the same as those described in the prior art. It is. Moreover, description of the molten metal is omitted.
[0029]
Here, the cast iron 300 will be described.
The casting bowl 300 has a substantially rectangular parallelepiped shape, and a runner 310 having a runner wall portion 320 and a runner bottom portion 330 is engraved on the upper surface thereof. The runner 310 starts from a calming part 350 that receives the molten metal flowing down from the molten metal furnace. The calming part 350 is widened and dredged with respect to other runners connected to it. A rectifying unit 360 is provided from the calming unit 350 through the runner 310. The rectifying unit 360 is also widened and wrinkled compared to the runner 310. The runner 310 ahead of the rectifying unit 360 reaches the hot water outlet 340 with a gentle downward slope, and opens on the side wall surface of the cast iron 300.
[0030]
Next, the flow of the molten metal when the cast iron 300 is used will be described.
The molten metal flowing down from the nozzle trough 4 is temporarily stored in the calming part 350 and received and settled here. The molten metal flowing out from the calming part 350 passes through the runner 310 and enters the rectifying part 360. Since the rectifying unit 360 is also widened and drowned compared with the runner 310, the molten metal is once received. As a result, the flow of the molten metal flowing out from the rectifying unit 360 is rectified, passes through the previous runner 310, and reaches the outlet 340. The molten metal reaching the hot water outlet 340 is poured into the casting groove 200 while being rectified, and is cast between the casting groove bottom 230 and the steel strip 25.
[0031]
Using this casting rod 300, the molten metal flowing down from the nozzle rod 4 is once received by the casting rod 300, rectified, and poured into the casting groove 200, thereby generating cracks in the continuously cast bar produced. However, the present inventors aimed to further reduce the occurrence of cracks. Then, the inventors of the present invention only use the casting iron 300, and when the molten metal is poured from the casting iron 300 into the casting groove 200, the height of the casting groove bottom 230 and the runner bottom at the outlet 340 is increased. Due to the difference and the horizontal inertia of the molten metal, the position where the molten metal contacts the bottom of the casting groove (denoted as L2 in the drawing) is separated from the outlet 340. As a result, we hypothesized that the generation of oxides and turbulence might be caused.
[0032]
In particular, when molten metal is poured, Zn and Zn-Al alloys that are susceptible to oxidation by oxygen in the atmosphere tend to generate these oxides, causing cracks in continuously produced bars to be produced. It was thought that there was.
[0033]
Based on the hypothesis, a cast iron improved from the cast iron 300 was manufactured in consideration of further suppressing the impact when the molten metal is poured from the cast iron 300 to the cast groove bottom 330. And when the continuous cast bar was manufactured using this improved cast iron, it turned out that generation | occurrence | production of a crack can be suppressed. Hereinafter, this improved cast iron will be described with reference to FIG.
[0034]
FIG. 1 is a perspective view showing a state in which an improved casting rod according to the present invention is installed on a casting wheel of a rotary strip casting machine.
In FIG. 1, the nozzle rod 4, the casting wheel 21, the casting groove 200, the casting groove top portion 210, the casting groove wall portion 220, the casting groove bottom portion 230, the roll 22, and the steel strip 25 are the same as those described in the prior art. It is the same. Moreover, description of the molten metal is omitted.
[0035]
Here, the cast iron 500 will be described.
The cast iron 500 also has a substantially rectangular parallelepiped shape similar to the cast iron 300 described with reference to FIG. 2, and a runner 510 having a runner wall portion 520 and a runner bottom portion 530 is engraved on the upper surface thereof. It is. The runway 510 starts from a calming portion 550 that receives the molten metal flowing down from the molten metal furnace. The calming part 550 is widened and drooped from other runners connected to it. A rectifying unit 560 is provided from the calming unit 550 through the runner 510. The rectifying unit 560 is also widened and wrinkled compared to the runner 510. The above part has the same configuration as the casting rod 300.
[0036]
The runner 510 ahead of the rectifying unit 560 reaches the hot water outlet 540 with a gentle downward slope and opens to the side wall surface of the casting bowl 500.
Here, the structure of the hot water outlet 540 will be described. The lower surface tip 505 that is the bottom surface of the tap 540 is not a uniform plane, and the lower portion of the tap 540 protrudes downward as a lower projection 506. The lower protrusion 506 is placed in the casting groove 200 of the rotating casting wheel 21 and slides with the casting groove wall 220 to stabilize the position of the casting rod 500 with respect to the casting wheel 21. At this time, the lower surface tip 505 slides with the casting groove top 210.
[0037]
The above-described runner 510 advances in the lower protrusion 506 while being inclined downward, and reaches the hot water outlet 540. As a result, the position of the runner bottom 530 in the hot water outlet 540 is located below the casting groove top 210.
In addition, it is preferable from a viewpoint of position stabilization that the lower surface front-end | tip part 505 except the lower surface protrusion part 506 of the casting rod 500 has an upward convex circular arc shape along the outer peripheral shape of the casting wheel 21. FIG.
[0038]
Next, the flow of the molten metal in the case where the cast iron 500 is used will be described. First, the molten metal flowing down from the nozzle rod 4 is received by the calming portion 550, passes through the runner 510, and is rectified by the rectifying portion 560. The configuration to be performed is the same as the configuration of the cast iron 300 described in FIG.
[0039]
The runway 510 extending from the rectifying unit 560 to the hot water outlet 540 draws a downward curve and reaches the hot water outlet 540 as it approaches the hot water outlet 540. As a result, the molten metal that has exited the rectifying unit 560 passes through the runner 510 while being rectified, and is gently applied with a downward force at the lower surface projection 506 to be poured into the casting groove 200 from the hot water outlet 540. In addition to this applied downward force, the position of the runner bottom 530 is located below the casting groove top 210, so that the molten metal is poured from the casting trough 500 to the casting groove 200 with almost no impact. It gets hot. The poured molten metal is sandwiched and cast between the casting groove bottom 230 and the steel strip 25.
[0040]
In the present invention, the height difference between the casting groove bottom 230 and the runner bottom at the tap 540 can be set to a desired value by the design of the bottom projection 506, but it should be approximately 10 mm or less. Is preferred.
[0041]
Furthermore, in addition to shortening the difference in level between the runner bottom 530 and the level of the molten metal poured into the casting groove, the lower surface protrusion 506 imparts a downward force gently to the molten metal. The position at which the molten metal flowing out from the pouring gate 540 comes into contact with the bottom of the casting groove (denoted as L1 in the drawing) is drawn near the pouring gate 540, and the impact when the molten metal collides with the casting groove bottom. Preferably, the molten metal is brought into contact with the bottom of the casting groove at a position less than 20 mm from the front end of the pouring gate 540, more preferably at a position of approximately 10 mm.
[0042]
In this way, it was possible to suppress the occurrence of cracks in manufactured continuous cast bars including Zn and Zn—Al alloys. And when the manufactured continuous cast bar by which generation | occurrence | production of the crack was suppressed was rolled, the uniform excellent in the structure | tissue was able to be manufactured.
[0043]
Here, the material of the cast iron 500 is preferably a ceramic member having low thermal conductivity and easy to process, and examples thereof include a calcium silicate heat insulating material. This is because, when the thermal conductivity of the cast iron 500 is low, the molten metal is not rapidly cooled, and the flow is rectified, and at the same time, the cooling balance is not lost.
[0044]
Example 1
A zinc-alloy molten metal was prepared by melting the pure zinc bullion specified in JIS H 2107 and the type 1 aluminum bullion specified in JIS H 2102 in a tilting furnace, and transferred to the molten metal furnace. The transferred Zn-Al alloy molten metal was supplied to a rotary strip casting machine using a cast iron 500 while maintaining 420 to 430 ° C in a molten metal furnace.
At this time, the height difference between the bottom of the runner and the bottom of the casting groove was 8 mm, and the position where the molten metal that had flowed out of the pouring tap contacted the casting groove bottom was 10 mm from the tip of the pouring tap.
As a result, a good Zn-Al alloy continuous cast bar free from cracks was obtained.
[0045]
(Example 2)
The purest zinc metal specified in JIS H 2107 was melted in a tilting furnace, and the molten zinc was transferred to the molten metal furnace 1. The transferred zinc molten metal was supplied to a rotary strip casting machine using a cast iron 500 while maintaining 430 to 460 ° C. in a molten metal furnace. At this time, the height difference between the bottom of the runner and the bottom of the casting groove was 10 mm, and the position at which the molten metal flowing out from the tap was in contact with the bottom of the casting groove was 10 mm from the tip of the tap.
As a result, a good zinc continuous cast bar free of cracks could be obtained.
[0046]
(Comparative Example 1)
Zn-Al was used under the same conditions as in Example 1 except that the casting iron used was a comparative casting iron having a straight casting groove and not having a calm part, a rectifying part, and a sloping outlet. An alloy continuous casting bar was manufactured.
The obtained Zn-Al alloy continuous cast bar had cracks, and the quality was remarkably deteriorated.
At this time, the difference in height between the bottom of the runner and the bottom of the casting groove was 20 mm, and the position where the molten metal flowing out from the tap was in contact with the lower part of the casting groove was 30 mm from the tip of the tap.
[0047]
(Comparative Example 2)
A zinc continuous cast bar was produced under the same conditions as in Example 2 except that a cast iron for comparison similar to Comparative Example 1 was used.
Cracks occurred in the obtained zinc continuous casting bar, and the quality was remarkably deteriorated.
At this time, the difference in height between the bottom of the runner and the bottom of the casting groove was 20 mm, and the position where the molten metal flowing out from the outlet was in contact with the lower part of the casting groove was 30 mm from the tip of the outlet.
[0048]
【The invention's effect】
As described above, the present invention is a casting rod used for producing a continuous casting bar by pouring molten metal into a rotary strip casting machine,
The molten metal that flows into the casting groove provided in the casting wheel of the rotary strip casting machine provided at the front end of the runway, the runway through which the molten metal that has flowed out from the calming part passes, and the molten metal flowing down from the calming part. And a hot water outlet for pouring hot water,
The bottom of the runner is connected to the tap with a downward slope,
The bottom of the top end of the tap is located below the top of the casting groove is a casting rod for producing a continuous casting bar,
The casting trough is to stably reduce the height difference between the bottom of the runner and the bottom of the casting groove to a desired value, and to reduce the impact when the molten metal collides with the bottom of the casting groove. It can suppress that a crack generate | occur | produces in the manufactured continuous casting bar.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which an improved cast iron according to the present invention is installed on a cast wheel.
FIG. 2 is a perspective view showing a state in which a casting rod according to an intermediate stage of the present invention is installed on a casting wheel.
FIG. 3 is a perspective view showing a state in which a nozzle rod according to a conventional technique is installed on a casting wheel.
FIG. 4 is a schematic cross-sectional view of a continuous casting and rolling method using a rotary strip casting machine according to the prior art.
[Explanation of symbols]
2. 2. Rotary strip casting machine 3. Molten metal 4. Nozzle に according to the prior art Continuous casting bar 300. Cast iron 310 in an intermediate stage of the invention. Runway 330. Runway bottom 340. Outlet 350. Calming part 360. Rectifier 500. Improved cast bar 510. according to the present invention. Yudo 530. Runway bottom 540. Outlet 550. Calm part

Claims (7)

A molten metal flowing down from a nozzle is poured into a rotary strip casting machine having a casting groove and a steel strip, and is used for producing a continuous casting bar,
And stopper receiving a falling to come the molten metal, a calming section to calm down, the runners molten metal flowing out passes from the calming section, a rectifying section between the tap hole to be described later and the calming section, said runner A pouring gate for pouring the molten metal into a casting groove provided on a casting wheel of the rotary strip casting machine provided at the tip of the rotary strip casting machine,
The calming portion is widened and crumpled from the runner that continues to it,
The rectifying unit is widened and squeezed from the runner and the runner connected to the runway,
The bottom of the runner is connected to the tap with a downward slope,
A casting rod for producing a continuous casting bar, wherein a bottom portion at a tip of the pouring gate is located below a top portion of the casting groove. A casting rod for use in manufacturing the continuous cast bar according to claim 1,
A casting rod for producing a continuous casting bar, wherein a difference in height between the bottom of the runner and the bottom of the casting groove is 10 mm or less. A casting rod for use in producing the continuous cast bar according to claim 1 or 2,
The continuous cast bar is a cast bar for producing a continuous cast bar, which is a bar of Zn or Zn-Al alloy. A production method for producing a continuous cast bar using a rotary strip casting machine having a casting groove and a steel strip,
Using a cast iron for producing a continuous cast bar according to any one of claims 1 to 3,
The molten metal flowing down from the nozzle is received and calmed by the calming part, and the molten metal flowing out from the calming part passes through the runner and enters the rectifying part, and the rectifying part also receives the molten metal and flows out from the rectifying part. The rectified molten metal is brought to the outlet, and the molten metal is poured into a casting groove while being rectified, and is cast by being sandwiched between a casting groove bottom and a steel strip to produce a continuous casting bar. Manufacturing method of continuous casting bar. It is a manufacturing method of the continuous cast bar according to claim 4,
The molten metal poured into the casting groove from the tip of the tap is 20 mm from the tip of the tap.
A method for producing a continuous cast bar, wherein the continuous cast bar is in contact with the bottom of the cast groove at a position less than the range. It is a manufacturing method of the continuous cast bar according to claim 4 or 5,
The continuous casting bar is a bar of Zn or Zn-Al alloy, characterized in that it is a continuous casting bar manufacturing method.   A Zn wire or Zn-Al alloy wire produced by rolling a Zn or Zn-Al alloy continuous cast bar produced by the method for producing a continuous cast bar according to claim 6.

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