JPS6053096B2 - Copper alloy for molten metal quenching roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling roll used in the production of a thin metal sheet directly from molten metal, as typified by the production of an amorphous alloy ribbon. The invention relates to copper alloys for use in industrial applications.

Amorphous ribbon, which exhibits excellent properties and is used in audio magnetic head materials and power transformer materials, requires precise plate thickness accuracy and surface smoothness, so it is advantageous to manufacture it using the twin roll method. It is said that there is. As shown in Fig. 1, the twin-roll amorphous ribbon manufacturing method rapidly cools molten metal 3 falling from a nozzle 2 between a pair of cooling rolls 1 and 1 rotating at high speed, and then rolls and forms the metal. This is a method for obtaining an amorphous alloy ribbon 4, and since both sides of the molten metal 3 are in contact with the cooling roll surface and the dimensions are regulated, the surface smoothness of the obtained amorphous alloy ribbon 4 is improved. in good condition,
It also has features such as high accuracy in plate thickness dimensions.

In addition, in FIG. 1, what is indicated by the symbol 5 is a high frequency heating ring for heating the molten metal 3. The material of the cooling rolls 1 and 1 is high-speed steel (SKH
), die steel (SKD), pure copper, beryllium copper, etc. were commonly used. However, subsequent research has shown that, especially in such a twin roll process, when continuous operation is carried out for long periods of time aiming at industrial production scale, disadvantageous phenomena such as those shown in 1 to 3 below may occur. It's becoming clear.

Namely, 1. While the roll is in use, the surface of the roll gradually becomes rough and the surface of the metal strip becomes dirty. 2. While the roll is in use, the thickness of the metal strip becomes noticeably variable. 3.
While the roll is in use, cracks occur on its surface, making subsequent operation impossible.These phenomena become more pronounced as the temperature of the molten metal is higher and as the amount of molten metal that is bitten by the roll increases. , other than amorphous ribbon production, such as carbon steel, stainless steel, Ni-based alloy, carbon-resistant alloy, Ti
This is also a major hindrance to the development of the so-called direct rolling method, in which strips are made directly from molten metals of high melting point materials such as molten metals.

From the above-mentioned viewpoint, the present inventors believe that when carrying out the twin-roll process, even in continuous operation on an industrial scale, an amorphous alloy ribbon with a uniform thickness and a smooth surface can be produced. In order to find a means by which crystalline metal bands can be obtained over a long period of time, we first conducted basic research to clarify the causes of the phenomena shown in 1 to 3 above, and the following 4 to 6.
The following facts were confirmed.

5 In particular, as shown in Table 1, the composition of amorphous alloys used for magnetic head materials and power transformer materials contains large amounts of Si and B, which are naturally different from Fe and Cu due to erosion. It is easy to cause

Therefore, although it is rapidly cooled, it can be concluded that due to an increase in the roll surface temperature and long-term use, a microscopic reaction occurs between the roll surface and the molten metal, leading to roughening of the roll surface. Furthermore, in the case of molten metal such as Ti, carbon steel, high alloy steel, stainless steel, Ni-based alloy, CO-based alloy, etc.
Since the casting temperature is extremely high at 1600-2000℃, B
Even if the Si content is low, the roll. It is easy to cause a reaction between the surface and the molten metal, and the variation in plate thickness during 5-roll operation is due to plastic deformation of the roll surface.In other words, the molten metal falling between the twin rolls is very rapid!
Before being cooled and pressurized at the contact point of the roll, the fluidity deteriorates and its deformability deteriorates, while the roll surface
As the temperature rises, the strength will decrease, and these two factors will combine to amplify the plastic deformation of the roll. , heat fatigue cracks will occur on the roll surface due to thermal cycles. Taking these matters into consideration, the present inventors developed a method, for example, the twin roll method, in which the molten metal is solidified and formed by contacting the molten metal. For rolls used for such purposes, the material must be one that does not easily react with molten metals containing large amounts of 4B and Si, and one that does not easily react with high-temperature molten metals such as 5Ti, Fe, Ni, etc. [Phase] It must have high thermal conductivity so that it can enhance the heat removal effect and promote the amorphization of the molten metal, and also reduce the temperature rise on the roll surface. , [Co., Ltd.] In order to prevent roll plastic deformation and cracking due to thermal fatigue, we use materials that have excellent mechanical properties (hardness, tensile strength, elongation, etc.) at high temperatures. Then, above 1~
From the perspective of eliminating the disadvantages shown in 3, further research revealed that copper alloys in which a large amount of Cr is dispersed are less likely to react with molten metals containing B and Si. In addition, it is not easily attacked by high-temperature molten metals such as T1 and steel, and when this alloy is used as a member that comes into contact with molten metal, it has an excellent heat removal effect, and even when used for a long time, the surface will not crack or deform. We have come to the conclusion that this does not occur.
Furthermore, they discovered that by adding Zr or P to this copper alloy, its resistance to thermal fatigue cracking and strength could be improved, making it a material suitable for use in molten metal quenching rolls such as those used in the twin roll process. .

Therefore, the present invention has been made based on the above-mentioned knowledge, and the alloy used in a molten metal quenching roll such as an amorphous alloy ribbon production roll, a direct rolling roll, or an immersion casting roll is made of Cr: 2.5-17.0%, P
Zr: 0.005 to 0.25%, further containing Zr: 0.02 to 1.50% as necessary, and the remainder consisting of Cu and unavoidable pure substances (the above weight %, below %) (indicates weight percent), it is characterized in that roughness, plastic deformation, and surface cracking in the roll during use are significantly reduced.

Next, in the copper alloy for a molten metal quenching roll of the present invention,
The reason why the contents of the constituent elements are limited as described above will be explained.

(a) Cr The Cr component has the effect of preventing "wetting" and erosion of the copper alloy constituting the roll against molten metal, especially "wetting" and erosion against molten metal containing a large amount of B and Si, and It also has the effect of improving the strength and hardness of copper alloys at high temperatures.
．． If the content is less than 5%, the desired effect cannot be obtained; on the other hand, if the content exceeds 17.0%, not only will the thermal conductivity and ductility of the alloy decrease, but also the Since it becomes difficult to dissolve, the content should be reduced to 2.
It was set at 5 to 17.0%.

(b) Zr The Zr component improves the high temperature ductility of the alloy, especially 200 to 60 Cf'
Since it has the effect of improving the ductility in the temperature range of C and improving the thermal fatigue cracking resistance, it is included as necessary when these characteristics are required, but if the content is 0.
If it is less than 0.02%, the desired effect of improving the above action cannot be obtained,
On the other hand, if the content exceeds 1.50%, not only will no further improvement effect appear, but on the contrary it will become difficult to melt and the plastic workability of the alloy will decrease. was set at 0.02 to 1.50%.

(c) P The P component not only has the effect of suppressing segregation in the ingot, but also has the effect of uniformly and finely dispersing Cr that crystallizes as primary crystals, thereby improving the mechanical strength of the alloy. However, if the content is less than 0.005%, the desired effect on the pre-action cannot be obtained, and on the other hand, if the content exceeds 0.250%, the thermal conductivity will deteriorate. 0.
It was set at 0.005% to 0.250%.

Furthermore, in the copper alloy of the present invention, for the purpose of improving the strength, Fe, Ni, and C are added in an amount of 0.05 to 0.50%.
One or more of O, Cd, Sn, Ag, and In, and 0.01 to 0.1% of C, each of which is 0.05%, for the purpose of further improving heat resistance. ~0.
50% of Al, Mg, Ti, Si, Be, B, Hf, and one or more of rare earth elements, and 0.01% of each as a deoxidizing agent for ingot cleaning action.
Even if one or more of Ca, Li, and Mg are contained in an amount of up to 0.20%, the above characteristics will not be impaired in any way.

Note that suitable molten metal quenching rolls to which the copper alloy of the present invention is applied include rolls for producing amorphous alloy ribbon (regardless of whether it is a one-roll method or a twin-roll method), a molten metal quenching roll that is suitable for applying the molten metal This refers to rolls for rolling, mold rolls used in immersion casting, etc., but in addition, the copper alloy of the present invention can also be applied to rolls for holding down processed materials and rolls for changing running direction in dip forming, hot-dip plating, etc. Of course, good results can be obtained even with this method.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 Using a high frequency induction heating furnace, in a vacuum atmosphere,
Each 100k9 copper alloy having the composition shown in Table 2 was melted into an ingot in a graphite crucible.

Subsequently, this was hot forged to an outer diameter of 21", length:
After processing into a Ni cylinder, it was held at a temperature of 1000°C for 1 hour, water quenched, and then heat treated at a temperature of 480°C for 2 hours, and the outer diameter was 20077E17! ，
Thickness: 30r! ! The copper alloy roll 1 of the present invention is made by machining it to a size of T, length: 20- to form a sleeve.
-10 and conventional alloy rolls 11-14 were manufactured, one pair each. The conventional alloy roll 13 was made of oxygen-free copper (0FHC), and the conventional alloy roll 14 was made of beryllium copper.

Then, using these rolls, a twin roll for manufacturing an amorphous alloy ribbon was assembled.

Next, to this, CO: 70% as an amorphous alloy,
A molten metal having a composition of 5% Fe, 12% Si, and 13% B was dropped from a nozzle and cooled to form an amorphous ribbon.

The above nozzle is made of quartz and has a nozzle diameter of 2. ``Temperature of hot water:
The conditions were 1260°C and a weight of approximately 1k9 per tap, and the nozzle and tundish were kept warm by high-frequency heating.

Further, the rotation speed of the twin rolls was 3000 rpm, and the roll gap was set so that the amorphous ribbon thickness was 30 ILm.

At this time, the width of the amorphous ribbon was about 20 wa.
For each of the above rolls, perform the molten metal drop rolling test of 1 to 1 (2), and after the test, measure the difference in plate thickness of the amorphous ribbon, visual inspection of the surface skin of the amorphous ribbon, and the amount of roll deformation. are also shown in Table 2.

The difference in thickness of the amorphous ribbon is measured by observing the cross section with a microscope, and the surface texture is 01, which is approximately the same as the skin immediately after the start of the test, and Δ, which is considerably roughened. Those that did not form a ribbon were evaluated as ×.

Further, the roll variation was expressed by actually measuring the unevenness of the roll surface using a surface roughness measuring device, and the difference between the maximum and minimum. From the results shown in Table 2, the roll made of the alloy of the present invention shows no noticeable change in the product obtained even after 10 shots, and its properties are significantly improved compared to conventional alloy/metal rolls. It turns out that it is excellent. It is clear that the alloy of the present invention is extremely useful as a material for molten metal quenching rolls for industrially producing amorphous ribbons.・Example 2 One pair each of the copper alloy rolls 1 to 10 of the present invention and the conventional alloy rolls 11 to 14 having the same dimensions and the same composition and the same process as in Example 1 were manufactured, This was installed as a water-cooled roll in a vacuum melting casting direct rolling apparatus as shown in FIG.

FIG. 2 shows a titanium melt-casting direct rolling apparatus which incorporates a shooter 13, a plasma beam torch 14, a hearth 15, a water-cooled roll 16 for quenching molten metal, a pinch roll 18, and a winding roll 19 in a vacuum vessel 11. This is a schematic configuration diagram, in which sponge titanium sent from a hopper 12 to a hearth 15 via a shooter 13 is melted with a plasma beam torch 14, and then supplied between water-cooled rolls 16 and 16 to be rapidly solidified. This is to obtain a titanium plate 17 having uniform properties by rolling at the same time.

Next, a titanium equivalent to the JIS standard was directly melted and cast using the above-mentioned apparatus.

At this time, one round of casting and rolling was about 1 kg, the rotation speed of the water-cooled rolls (twin rolls) 16 was 30 rpm, and the thickness of the obtained titanium plate was 0.5 Tns and the width was 20 m. For each of the rolls, conduct a melt casting rolling test once to once,
After the test was completed, the difference in thickness of the titanium plates, the condition of the surface texture, and the amount of deformation of the roll were measured, and the results are shown in Table 3.

Note that the plate thickness was measured with a micrometer and evaluated based on the difference between the maximum thickness and the minimum thickness in the width direction. In addition, the surface skin of the plate is as shown in Example 1.
Similarly to the skin immediately after the start of the test, those that were almost the same were evaluated as 01, those with considerably rough skin were evaluated as Δ, and those that could not be rolled were evaluated as ×.

The irregularities on the roll surface are measured using a surface roughness measuring machine. The difference between the maximum and minimum values is expressed as the difference between the maximum and minimum values.

From the results shown in Table 3, the roll made of the alloy of the present invention shows no noticeable change in the product obtained even after 10 charges, and has significantly superior properties compared to rolls made of conventional alloys. I know what you're doing.

As described above, according to the present invention, the surface will not be eroded even if it comes into contact with various molten metals repeatedly for a long time, there is no risk of plastic deformation, and the heat removal effect from the molten metal will be improved. It is possible to obtain an extremely superior alloy, and when used as a raw material for molten metal quenching rolls for manufacturing amorphous alloy ribbons or for direct rolling of high-melting point metals, it is possible to produce high-precision products for a long time. This brings about industrially useful effects such as making it possible to manufacture products over a long period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram for explaining the twin roll method for manufacturing an amorphous alloy ribbon, and FIG. 2 is a schematic diagram of a titanium vacuum melting casting direct rolling apparatus. In the drawings, 1... cooling roll, 2...
... Nozzle, 3... Molten metal, 4...
Amorphous metal ribbon, 5...high frequency heating ring, 11.
...Vacuum container, 12...Hopper, 13...
... Shooter, 14 ... Plasma beam torch, 15 ... Hearth, 16 ... Water-cooled roll for quench rolling of molten metal, 17 ... Titanium plate, 18 ...
... Zenthy roll, 19... Winding roll.

Claims (1)

[Claims] 1 Cr: 2.5 to 17%, P: 0.005 to 0.25%, and the remainder is Cu and unavoidable impurities (weight %). Copper alloy for quenching rolls for molten metal. 2 Contains Cr: 2.5 to 17%, P: 0.005 to 0.25%, and further contains Zr: 0.02 to 1.5%, with the remainder consisting of Cu and inevitable impurities. A copper alloy for a molten metal quenching roll, characterized in that it has a composition (the above weight %).