JPH04305339A - Method for continuously casting copper alloy - Google Patents

Abstract

PURPOSE:To present a continuous casting method of copper alloy that the continuous casting is executed without generating the surface defect on the coiling time and the annealing time for cast billet without problem. CONSTITUTION:On a horizontal continuous casting method that a molten copper alloy 2 is passed through a casting mold 3 composed of a solidifying zone 3a and a spare solidifying zone and a cast billet 4 is obtained, the obtained cast billet 4 is coiled via a natural air cooling zone 5 and a water cooling zone 6, this is the continuous casting method for the copper alloy that the surface defect caused on the intergranular crack on the time for coiling and annealing the cast billet by forcibly heating the cast billet 4 went out from the spare solidifying zone 3b of the cast mold 3 to the molten metal temperature range, keeping the temperature of copper alloy to be cast in the molten body state until just before entering to the water cooling zone 6, and reducing the hardness.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves passing an age-hardening type or spinoldal decomposition type molten copper alloy through a casting mold consisting of a solidification zone and a pre-solidification zone to obtain an ingot.
This invention relates to a horizontal continuous casting method in which the obtained ingot is rolled up via a solution temperature range heating zone and a water cooling zone.

0002

2. Description of the Related Art FIG. 2 is a diagram showing the structure of an example of an apparatus for carrying out a conventional continuous casting method for age-hardening copper alloys. In FIG. 2, 21 is a molten metal holding furnace for holding the molten metal 22, 23 is a casting mold having a solidification zone 23a and a pre-solidification zone 23b provided on the outlet side of the molten metal 22 of the molten metal holding furnace 21, and 24 is a casting mold 23. 25 is a natural air cooling zone for air cooling the ingot 24; 26 is a water cooling zone provided on the rear side of the natural air cooling zone 25; 27 is the ingot 24 pulled out from the casting mold 23. 28 is a facing device for the ingot 24, 29
3 is a cutting device for the ingot 24, and 30 is a winding device for the ingot 24.

In the conventional age-hardening copper alloy continuous casting apparatus shown in FIG. 2, the ingot 24 formed in the solidification zone 23a
After passing through the pre-coagulation zone 23b and the natural air cooling zone 25, it enters the water cooling zone 26 where it is cooled to room temperature and wound up. Here, the pre-coagulation zone 23b is the coagulation zone 2
3a and is not clearly decomposed, but if the solidification zone 23a shifts toward the exit side due to changes in the temperature of the molten metal, the flow rate and temperature of the casting mold cooling fluid, and fluctuations in the drawing speed, the molten metal will not solidify and will not solidify. This is necessary to prevent the ingot from blowing out from the outlet of the mold 23, and also has the effect of absorbing heat from the ingot solidified in the solidification zone 23a and lowering the temperature of the ingot to a certain temperature. Further, the natural air cooling zone 25 is necessary to prevent the water in the water cooling zone 26 from entering the casting mold 23 for some reason, and usually 2~
It is set to 3m. Furthermore, the water cooling zone 26 is used to prevent the deterioration of the drawing device 27 from worsening if the ingot 24 enters the drawing device 27 at high temperatures, and to make the ingot 24 easier to handle. This water cooling zone 26 may not exist.

0004

[Problems to be Solved by the Invention] Incidentally, the ingot withdrawal speed currently in practical use in continuous casting of age-hardenable copper alloys is from 0.001 m/s to 0.008 m/s.
In the slowest case, it takes 2 hours before entering the water cooling zone 26.
000 seconds, even the fastest case takes 250 seconds. On the other hand, the temperature of the ingot 24 immediately after passing through the pre-solidification zone 23b is 5
Generally, the temperature is about 00 to 700 degrees Celsius, and the temperature in the air cooling zone 25 is 350 to 600 degrees Celsius.
As a result, the age hardening type or spinoldal decomposition type copper alloy ingots harden, causing surface defects during winding and subsequent annealing.

[0005] The purpose of the present invention is to solve the above-mentioned problems,
The object of the present invention is to provide a method for continuous casting of copper alloys, which does not cause surface defects during winding and annealing of an ingot and allows good continuous casting.

[0006]

[Means for Solving the Problems] The continuous casting method for copper alloys of the present invention includes passing a molten age-hardening type or spinodal decomposition type copper alloy through a casting mold comprising a solidification zone and a pre-solidification zone to obtain an ingot. In a horizontal continuous casting method in which the obtained ingot is rolled up via a natural air-cooling zone and a water-cooled zone, the ingot is rolled up at any position after leaving the pre-solidification zone of the casting mold and just before entering the winding machine. The copper alloy is maintained in a solution temperature range specific to the copper alloy for 30 seconds or more and 20 minutes or less, and then immediately cooled with water to maintain the solutionized state and reduce surface defects in rolled products made from the ingot. That is.

[0007]

[Function] In the above-mentioned configuration, the ingot is held in the solution temperature range for a certain period of time at any position after leaving the pre-solidification zone of the casting mold and just before entering the winder, and then immediately cooled with water to melt the ingot. Since the ingot that has been made into a carbonized state has a large elongation, it is possible to efficiently prevent micro-cracks when it is bent and rolled up using a winding machine. In addition, as the yield point is lowered, the dislocation density inside the coiled ingot is also reduced, which prevents the formation of pores due to the accumulation of dislocations during annealing, thereby preventing grain boundary embrittlement or embrittlement due to pore formation. Destruction can be suppressed efficiently. In the present invention,
Although various conventionally known devices can be used as the heating device used for heating, induction heating is the most suitable heating means due to its efficiency and effectiveness. Further, the heating time is 1 minute in the air. In addition, the heating zone in the solution temperature range may be at any position before entering the winder,
Since cooling the ingot to room temperature and then reheating it involves a lot of energy loss, it is most efficient to provide it between the casting mold and the drawing device as shown in FIG. Note that holding the ingot in the solution temperature range for more than 30 seconds is insufficient because if it is held for less than 30 seconds, it is insufficient to bring the ingot to a solution state, and if it is held for more than 20 minutes, the equipment becomes large and uneconomical. This is because.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the construction of an example of an apparatus for carrying out the method for horizontal continuous casting of copper alloys of the present invention. In the example shown in FIG. 1, 1 is a molten metal holding furnace for holding molten metal 2;
3 is a casting mold having a solidification zone 3a and a pre-solidification zone 3b provided on the outlet side of the molten metal 2 of the molten metal holding furnace 1; 4 is an ingot continuously coming out from the casting mold 3; 5 is an ingot 4
a natural air cooling zone for air cooling, 6 a water cooling zone provided on the rear side of the natural air cooling zone 5, 7 a drawing device for drawing out the ingot 4 from the casting mold 3, 8 a facing device for the ingot 4, 9 is a cutting device for the ingot 4, and 10 is a winding device for the ingot 4, and these structures are the same as those of conventional devices. In the apparatus for carrying out the horizontal continuous casting method of the present invention, the ingot is heated to a solution temperature range in a part of the conventional natural air cooling zone 5 immediately before entering the water cooling zone 6 behind the pre-solidification zone 3a of the casting mold 3. A feature is that a heating device 11 is provided in a heating zone 12 for holding and heating.

In the apparatus shown in FIG. 1 as well, the basic continuous casting method is the same as that of the conventional apparatus, and its explanation will be omitted. In the case of age-hardenable copper alloys, the length of the normal solidification zone 3a is 0.05 to 0.3 m, the length of the pre-solidification zone 3b is 0.1 to 0.4 m, and the length of the natural air cooling zone 5 is 0.3 m. 3～
The length of the heating zone 11 is about 0.1 to 1.0 m. Further, a fluid such as water for cooling is flowing through the casting mold 3. In the present invention, the heating temperature of the copper alloy is set in the solution temperature range by the heating device 11, and the solution state is maintained by immediately cooling with water, and the ingot hardness is lowered, so that the copper alloy is heated at the time of winding and subsequent annealing. Eliminates surface defects.

An actual example will be explained below. EXAMPLE Beryllium copper alloys having various compositions shown in Table 1 are continuously cast using the apparatus shown in FIG. In addition to measuring the hardness of the ingots, we measured the hardness of the ingots for the inventive example in which heating was performed under the conditions shown in Table 1, the conventional example in which natural air cooling was performed without heating, and the comparative example in which the heating temperature was below the solution temperature. In order to reproduce the occurrence of surface defects that become apparent during the manufacturing process, the rolled ingot was
The number of surface defects of the plate material was measured after homogenization annealing for 4 hours at °C and rolling with a post-processing rate of 80%. The number of surface defects was calculated by visual observation per unit area (m2). Further, the ingot of the present invention was heated to a solution temperature range and then cooled in water, and the ingot that maintained the solutionized state had a soft hardness of about 150 or less. The results are shown in Table 1.

[0011]

[Table 1]

[0012] From the results in Table 1, it can be seen that the example of the present invention in which water cooling was performed after heating to the solution temperature range specific to copper alloys had a higher casting performance than the conventional example in which no heating was performed and natural air cooling was performed, and the comparative example outside the scope of the present invention. It was confirmed that the lump hardness was low and the number of surface defects after annealing was small. In addition, although the heating holding time was set to 4 minutes in the example, substantially the same tendency can be obtained as long as the heating holding time is within 30 seconds to 20 minutes.

[0013]

As is clear from the above description, according to the present invention, the ingot is forcibly melted at any position after exiting the pre-solidification zone of the casting mold and immediately before entering the winder. Immediately cooling with water after heating to a solution temperature range allows the ingot to maintain its soft state and eliminate surface defects during winding and annealing of the ingot.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an example of an apparatus for carrying out the horizontal continuous casting method of the present invention.

FIG. 2 is a diagram showing the configuration of an example of an apparatus for implementing a conventional horizontal continuous casting method.

[Explanation of symbols]

1 Molten metal holding furnace 2 Molten metal 3 Casting mold 3a Coagulation zone 3b Pre-coagulation zone 4 Ingot 5 Heating zone 6 Water cooling zone 7 Drawer device 8　Facing device 9 Cutting device 10 Winding device 11 Heating device 12 Heating zone

Claims (2)

[Claims] Claim 1: A molten age hardening or spinodal decomposition type copper alloy is passed through a casting mold consisting of a solidification zone and a pre-solidification zone to obtain an ingot, and the obtained ingot is passed through a natural air cooling zone and a water cooling zone. In the horizontal continuous casting method, the ingot is heated to a solution temperature range specific to the copper alloy for at least 30 seconds at any position after exiting the pre-solidification zone of the casting mold and just before entering the winder. 1. A continuous casting method for a copper alloy, characterized by maintaining a solutionized state by cooling with water immediately after holding the ingot for less than a minute, thereby reducing surface defects in rolled products made from the ingot. 2. The composition of the copper alloy is Be: 0.1 to 0.
6wt%, Ni+Co: 0.3-3.0wt%, Al+
2. The method for continuous casting of a copper alloy according to claim 1, wherein Si: 0 to 0.6 wt%, the balance being unavoidable impurities and copper, and the solution temperature is 750°C or higher.