WO2016047484A1

WO2016047484A1 - CASTING MOLD MATERIAL AND Cu-Cr-Zr ALLOY MATERIAL

Info

Publication number: WO2016047484A1
Application number: PCT/JP2015/075996
Authority: WO
Inventors: 翔一郎矢野; 敏夫坂本
Original assignee: 三菱マテリアル株式会社
Priority date: 2014-09-25
Filing date: 2015-09-14
Publication date: 2016-03-31
Also published as: KR20170059435A; KR102385768B1

Abstract

　This casting mold material has a composition comprising at least 0.3 mass% but less than 0.5 mass% of Cr, and 0.01-0.15 mass%, inclusive, of Zr, with the remainder being Cu and unavoidable impurities, and has needle-shaped precipitates or plate-shaped precipitates containing Cr.

Description

Mold material for casting and Cu-Cr-Zr alloy material

The present invention relates to a casting mold material used when casting a metal such as a steel material, and a Cu—Cr—Zr alloy material suitable for the casting mold material described above.
This application claims priority based on Japanese Patent Application No. 2014-195023 filed in Japan on September 25, 2014 and Japanese Patent Application No. 2015-169825 filed in Japan on August 28, 2015. The contents are incorporated herein.

Conventional molding materials used for casting steel materials, etc. have characteristics such as high-temperature strength that can withstand large thermal stress, high-temperature elongation that can withstand severe thermal fatigue environments, and wear resistance (hardness) at high temperatures. It is required to be excellent. For this reason, Cu—Cr—Zr alloys having these characteristics are used as mold materials for continuous casting. For example, Patent Document 1 discloses a casting mold material containing 0.3% to 1.2% Cr, 0.05% to 0.25% Zr, and the balance being Cu and impurities. .

In addition, it is known that Cu—Cr—Zr alloy has the above-mentioned characteristics improved by adding additional elements. For example, Patent Document 2 discloses that 0.005% to 0% in addition to Cr and Zr. .7% Ti, 0.003% to 0.1% Si, 0.005% to 1.5% of Fe, Ni, Co or one or more of Fe, Ni and Co, with the balance being Cu And a casting mold material made of impurities.

In the Cu—Cr—Zr alloys described in Patent Documents 1 and 2 described above, a supersaturated solid solution of Cr and Zr that becomes a non-equilibrium phase is formed by solution treatment, and Cr and Zr are dispersed by subsequent aging treatment. Therefore, mechanical properties such as high-temperature strength, high-temperature elongation, and wear resistance (hardness), electrical conductivity, and thermal conductivity are improved. In addition, in order to form the above-mentioned supersaturated solid solution, it is necessary to perform rapid cooling after the solution treatment.

JP 05-339688 A Japanese Patent Laid-Open No. 04-028837

By the way, the casting mold material is generally used by spraying a Ni—Cr alloy or the like excellent in heat resistance and wear resistance on the surface thereof to improve durability. When performing the above-mentioned thermal spraying treatment, for example, after performing heat treatment in a high temperature range of about 1000 ° C., it is gradually cooled without performing water cooling or the like. Hardness) and electrical conductivity are not sufficiently improved.
More specifically, after performing heat treatment in a high temperature range of about 1000 ° C., for example, when cooling is performed at a cooling rate of up to 800 ° C. at 25 ° C./min or less, granular Cr is contained during the slow cooling. Precipitates (Cr-based precipitates) and Zr-containing precipitates (Zr-based precipitates) are precipitated. Then, during the subsequent aging treatment, Cr and Zr, which have been solid-solved with these granular precipitates as nuclei, are precipitated, so that the precipitates grow and become coarse, which contributes to the precipitation strengthening mechanism. Goods cannot be secured sufficiently, and strength (hardness) cannot be improved.

The present invention has been made in view of the above-described circumstances, and even when it is gradually cooled after thermal spraying, the strength (hardness) and electrical conductivity can be sufficiently improved by subsequent aging treatment. It is an object of the present invention to provide a casting mold material and a Cu—Cr—Zr alloy material suitable for the casting mold material.

In order to solve the above problems, the casting mold material according to the first aspect of the present invention is a casting mold material used when casting a metal material, and Cr is 0.3 mass% or more and 0.0. Featuring less than 5 mass%, Zr 0.01 mass% or more and 0.15 mass% or less, the balance being composed of Cu and inevitable impurities, and having needle-like precipitates or plate-like precipitates containing Cr It is said.

In the casting mold material having this configuration, Cr is contained in a composition of 0.3 mass% or more and less than 0.5 mass%, Zr is contained in an amount of 0.01 mass% or more and 0.15 mass% or less, and the balance is composed of Cu and inevitable impurities. Therefore, strength (hardness) and electrical conductivity can be improved by depositing fine precipitates by aging treatment.
And since it has the acicular precipitate or plate-shaped precipitate containing Cr, it is suppressed that a granular precipitate is formed at the time of slow cooling after a thermal spraying process. For this reason, during the aging treatment after the thermal spraying treatment, it is possible to suppress the precipitation of Cr and Zr using the granular precipitates as nuclei, and the fine precipitates can be sufficiently dispersed, and the strength (hardness) is increased by the precipitation strengthening mechanism. ) And conductivity can be sufficiently improved.

Here, in the casting mold material according to the first aspect of the present invention, one or more elements selected from Fe, Si, Co, and P are further added in a total amount of 0.01 mass% or more and 0.0. It is preferable to contain 15 mass% or less.
In this case, since elements such as Fe, Si, Co, and P are contained within the above-described range, the formation of granular precipitates during slow cooling after thermal spraying is suppressed, and a needle containing Cr The formation of a plate-like precipitate or a plate-like precipitate is promoted. Therefore, fine Cr-based and Zr-based precipitates can be sufficiently precipitated by the aging treatment after the thermal spraying treatment, and the strength (hardness) and electrical conductivity can be reliably improved.

The Cu—Cr—Zr alloy material according to the second aspect of the present invention includes Cr of 0.3 mass% to less than 0.5 mass%, Zr of 0.01 mass% to 0.15 mass%, with the balance being Cu and It has a composition composed of inevitable impurities and is characterized in that when it is held at 800 ° C. after being subjected to a complete solution treatment, the holding time until the conductivity becomes 55% IACS is 25 sec or more.

In the Cu—Cr—Zr alloy material having this structure, when the holding time is 800 ° C. after the complete solution treatment, the holding time until the conductivity reaches 55% IACS is 25 sec or more. For example, even when it is gradually cooled after heating to a high temperature range of about 1000 ° C., unnecessary precipitation of Cr and Zr can be suppressed to ensure the solid solution amount of Cr and Zr.
Therefore, even when an aging treatment is performed after slow cooling, fine Cr-based and Zr-based precipitates can be dispersed, and strength (hardness) and electrical conductivity can be improved.

Here, in the Cu—Cr—Zr alloy material according to the second aspect of the present invention, one or more elements selected from Fe, Si, Co, and P are further added in a total amount of 0.01 mass%. It is preferable to contain 0.15 mass% or less.
In this case, since elements such as Fe, Si, Co, and P are contained within the above-mentioned range, Cr and Zr are not required even when gradually cooled after being heated to a high temperature range of about 1000 ° C., for example. It is possible to prevent solid precipitation and to secure the solid solution amount of Cr and Zr. Therefore, fine precipitates can be sufficiently precipitated by the aging treatment after slow cooling, and the strength (hardness) and electrical conductivity can be reliably improved.

In addition, in the Cu—Cr—Zr alloy material according to the second aspect of the present invention, the conductivity after cooling at 1000 ° C. to 600 ° C. after cooling at 1000 ° C. for 1 hour and cooling at 10 ° C./min. % IACS) is A, and when the conductivity (% IACS) after holding at 500 ° C. for 3 hours is B, it is preferable that B / A> 1.1.
In this case, even when the cooling rate from 1000 ° C. to 600 ° C. is gradually cooled to 10 ° C./min, the conductivity is improved by the subsequent heat treatment at 500 ° C. for 3 hours, and the strength due to precipitation hardening. It is possible to improve. For this reason, it is particularly suitable as a material for the above-mentioned casting mold material.

ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where it anneals after a thermal spraying process, intensity | strength (hardness) and electrical conductivity can fully be improved by subsequent aging treatment, and this casting mold A Cu—Cr—Zr alloy material suitable for the material can be provided.

It is a flowchart of the manufacturing method of the casting mold material which is one Embodiment of this invention. The T.V. of the Cu—Cr—Zr alloy material in the examples. T.A. T.A. It is explanatory drawing which shows a curve. It is a structure | tissue observation photograph of this invention example 2 and the comparative example 4. (A) is a structure observation photograph after the first aging treatment, (b) is after thermal spraying treatment and slow cooling, and (c) is a structure observation photograph after the second aging treatment. It is a figure which shows the structure | tissue observation photograph and element mapping result of the acicular precipitate or plate-like precipitate observed in Example 2 of this invention. (A) is a structure observation photograph, (b) is an enlarged view of a portion surrounded by a white line in (a), (c) is an element mapping result of Zr in (b), and (d) is a result of Cr in (b). It is an element mapping result. It is explanatory drawing which shows the Vickers hardness measurement position in an Example.

Hereinafter, a casting mold material and a Cu—Cr—Zr alloy material according to an embodiment of the present invention will be described.
The casting mold material according to this embodiment is used as a casting mold for continuous casting of steel materials and the like. In this embodiment, the Cu—Cr—Zr alloy material is used as a material for the above-described casting mold material.

The mold material for casting and the Cu—Cr—Zr alloy material according to the present embodiment include 0.3 mass% or more and less than 0.5 mass% of Cr, 0.01 mass% or more and 0.15 mass% or less of Zr, and the balance is Cu. And one or more elements selected from Fe, Si, Co, and P are included in a total of 0.01 mass% to 0.15 mass%.
Here, the reason why the component composition of the casting mold material and the Cu—Cr—Zr alloy material is defined as described above will be described below.

(Cr: 0.3 mass% or more and less than 0.5 mass%)
Cr is an element having an effect of improving strength (hardness) and conductivity by finely depositing Cr-based precipitates in the crystal grains of the parent phase by aging treatment.
Here, when the Cr content is less than 0.3 mass%, the amount of precipitation becomes insufficient in the aging treatment, and the effect of improving the strength (hardness) may not be sufficiently obtained. In addition, when the Cr content is 0.5 mass% or more, for example, when slow cooling is performed at a cooling rate from a high temperature range of about 1000 ° C. to a temperature of 800 ° C. or less of 25 ° C./min or less, Granular Cr-based and Zr-based precipitates are deposited, and these granular precipitates further grow in the aging treatment after slow cooling, thereby ensuring fine precipitates that contribute to the precipitation strengthening mechanism. There is a risk of disappearing.
From the above, in this embodiment, the Cr content is set within a range of 0.3 mass% or more and less than 0.5 mass%. In order to ensure that the above-described effects are achieved, the lower limit of the Cr content is preferably 0.35 mass% or more, and the upper limit of the Cr content is preferably 0.45 mass% or less. .

(Zr: 0.01 mass% or more and 0.15 mass% or less)
Zr is an element having an effect of improving strength (hardness) and electrical conductivity by finely depositing a Zr-based precipitate at a crystal grain boundary of the parent phase by aging treatment.
Here, when the content of Zr is less than 0.01 mass%, the precipitation amount becomes insufficient in the aging treatment, and there is a possibility that the effect of improving the strength (hardness) cannot be obtained sufficiently. Moreover, when content of Zr exceeds 0.15 mass%, there exists a possibility that electrical conductivity and thermal conductivity may fall. Moreover, even if it contains Zr exceeding 0.15 mass%, there exists a possibility that the effect of the further intensity | strength improvement may not be acquired.
From the above, in this embodiment, the content of Zr is set within a range of 0.01 mass% or more and 0.15 mass% or less. In order to ensure that the above-described effects are achieved, the lower limit of the Zr content is preferably 0.05 mass% or more, and the upper limit of the Zr content is preferably 0.13 mass% or less. .

(One or more elements selected from Fe, Si, Co, and P: 0.01 mass% or more and 0.15 mass% or less in total)
Elements such as Fe, Si, Co, and P, when subjected to slow cooling at a cooling rate of 25 ° C./min or less from a high temperature range of about 1000 ° C. to a temperature of 800 ° C. or less, for example, It has the effect of suppressing the precipitation of system precipitates.
Here, when the total content of one or more elements selected from Fe, Si, Co, and P is less than 0.01 mass%, the above-described effects may not be achieved. . On the other hand, when the total content of one or more elements selected from Fe, Si, Co, and P exceeds 0.15 mass%, the conductivity and thermal conductivity may be reduced. is there.
From the above, in this embodiment, the total content of one or more elements selected from Fe, Si, Co, and P is set within a range of 0.01 mass% to 0.15 mass%. ing. In order to ensure that the above-described effects can be achieved, the lower limit of the total content of one or more elements selected from Fe, Si, Co, and P is set to 0.02 mass% or more. Preferably, the upper limit of the total content of one or more elements selected from Fe, Si, Co, and P is preferably 0.1 mass% or less.

(Other inevitable impurities: 0.05 mass% or less)
Other inevitable impurities other than the above-described Cr, Zr, P, Fe, and Co include B, Ag, Sn, Al, Zn, Ti, Ca, Te, Mn, Ni, Sr, Ba, Sc, and Y. , Ti, Hf, V, Nb, Ta, Mo, W, Re, Ru, Os, Se, Rh, Ir, Pd, Pt, Au, Cd, Ga, In, Li, Ge, As, Sb, Tl, Pb , Be, N, H, Hg, Tc, Na, K, Rb, Cs, Po, Bi, lanthanoid, O, S, C and the like. Since these inevitable impurities may reduce the electrical conductivity and thermal conductivity, the total amount is preferably 0.05 mass% or less.

And the molding material for casting which is this embodiment has the acicular precipitate or plate-shaped precipitate containing Cr in the parent phase of Cu. The content of the needle-like precipitates or plate-like precipitates containing Cr is not particularly limited, but is preferably 200 to 10,000, more preferably 500 to 5,000, in an arbitrary cross section of 1 mm ² . Moreover, it is preferable that this needle-like precipitate or plate-like precipitate does not contain Zr.
Furthermore, fine Cr-based and Zr-based precipitates having a particle size of, for example, 1 μm or less are dispersed in the casting mold material according to this embodiment. The content of these fine Cr-based and Zr-based precipitates is not particularly limited, but is preferably 10 to 50000, more preferably 1000 to 30000, in an arbitrary cross section of 100 μm ² . These fine Cr-based and Zr-based precipitates are precipitated in the aging treatment after slow cooling.

The needle-like precipitates or plate-like precipitates described above are formed at the time of slow cooling after the thermal spraying process of spraying a Ni—Cr alloy having excellent heat resistance and wear resistance when manufacturing a casting mold material. More specifically, in the present embodiment, for a copper alloy containing 0.3 mass% or more and less than 0.5 mass% of Cr, 0.01 mass% or more and 0.15 mass% or less of Zr, and the balance being Cu and inevitable impurities. In addition, when heated to, for example, 1000 ° C. or higher at the time of thermal spraying, when cooling is performed so that the cooling rate from a high temperature range of about 1000 ° C. to 800 ° C. or lower is 25 ° C./min or less, Cr is contained. Needle-like precipitates or plate-like precipitates are deposited. This suppresses the precipitation of granular Cr-based and Zr-based precipitates (for example, precipitates having a particle size of 5 μm or more) during slow cooling.

Further, the Cu—Cr—Zr alloy material according to the present embodiment has the same composition as the above-mentioned casting mold material, and when it is kept at 800 ° C. after being subjected to the complete solution treatment, the conductivity is increased. Is 55 seconds or more until 55% IACS is reached.
That is, in the Cu—Cr—Zr alloy material according to the present embodiment, even if it is kept at 800 ° C. after the complete solution treatment, the precipitation of Cr-based and Zr-based precipitates is suppressed, and Cr and Zr The amount of solid solution is ensured. The upper limit value of the holding time until the conductivity reaches 55% IACS is not particularly limited, but is preferably 360 seconds and more preferably 120 seconds.

Furthermore, the Cu—Cr—Zr alloy material according to the present embodiment has an electric conductivity (% IACS) after cooling at 1000 ° C. to 600 ° C. with a cooling rate of 10 ° C./min after holding at 1000 ° C. for 1 hour. Then, when the conductivity (% IACS) after holding at 500 ° C. for 3 hours is B, the relationship is B / A> 1.1. More preferably, B / A> 1.15, and more preferably B / A> 1.2. The upper limit value of B / A is not particularly limited, but is preferably 2.0, and more preferably 1.5.
That is, in the Cu—Cr—Zr alloy material according to the present embodiment, even when the cooling rate from 1000 ° C. to 600 ° C. is 10 ° C./min after holding at 1000 ° C. for 1 hour, Conductivity is improved by heat treatment at 500 ° C. for 3 hours.

Next, a method for producing a casting mold material according to an embodiment of the present invention will be described with reference to the flowchart of FIG.

(Melting / Casting Process S01)
First, a copper raw material made of oxygen-free copper having a copper purity of 99.99 mass% or more is charged into a carbon crucible and melted using a vacuum melting furnace to obtain a molten copper. Next, the aforementioned additive elements are added to the obtained molten metal so as to have a predetermined concentration, and the components are prepared to obtain a molten copper alloy.
Here, as the raw material for the additive elements Cr and Zr, a material having a high purity is used. For example, a Cr material having a purity of 99.99 mass% or more is used, and a Zr material is having a purity of 99.95 mass% or more. Use one. Further, Fe, Si, Co, and P are added as necessary. As a raw material for Cr, Zr, Fe, Si, Co, and P, a mother alloy with Cu may be used.
And the ingot is obtained by pouring the prepared copper alloy melt into the mold.

(Homogenization step S02)
Next, heat treatment is performed to homogenize the obtained ingot.
Specifically, the ingot is homogenized in an air atmosphere at 950 ° C. or higher and 1050 ° C. or lower for 1 hour or longer.

(Hot processing step S03)
Next, hot rolling with a processing rate of 50% to 99% is performed on the ingot in a temperature range of 900 ° C. to 1000 ° C. to obtain a rolled material. The hot working method may be hot forging. Immediately after this hot working, it is cooled by water cooling.

(Solution treatment step S04)
Next, the rolled material obtained in the hot working step S03 is subjected to a heat treatment under conditions of 920 ° C. or higher and 1050 ° C. or lower and 0.5 hours or longer and 5 hours or shorter. The heat treatment is performed in, for example, air or an inert gas atmosphere, and cooling after heating is performed by water cooling.

(First temporary treatment process S05)
Next, after the solution treatment step S04, a first temporary effect treatment is performed, and precipitates such as a Cr-based precipitate and a Zr-based precipitate are finely precipitated to obtain a first temporary effect treatment material.
Here, the first temporary treatment is performed, for example, under conditions of 400 ° C. or more and 530 ° C. or less and 0.5 hours or more and 5 hours or less.
The heat treatment method during the aging treatment is not particularly limited, but it is preferably performed in an inert gas atmosphere. Further, the cooling method after the heat treatment is not particularly limited, but it is preferably performed by water cooling.
Through this process, the Cu—Cr—Zr alloy material according to this embodiment is manufactured.

(Spraying process S06)
Next, after the first temporary effect treatment step S05, Ni—Cr alloy or the like is sprayed on a predetermined portion of the surface of the Cu—Cr—Zr alloy material, and a coating layer is formed on the predetermined portion of the surface of the Cu—Cr—Zr alloy material. Form. Then, after this thermal spraying, the Cu—Cr—Zr alloy material on which the coating layer is formed is subjected to a heat treatment at 900 ° C. to 1000 ° C. for 15 minutes to 180 minutes.
This heat treatment is performed for diffusion bonding the Cu—Cr—Zr alloy material and the coating layer.
The cooling after the heat treatment after the thermal spraying is performed by slow cooling with a relatively low cooling rate such as furnace cooling. Here, the cooling rate of the slow cooling is such that the cooling rate in the range from the heat treatment temperature to 800 ° C. or less is 5 ° C./min or more and 70 ° C./min or less.

(Second aging treatment step S07)
Next, after the thermal spraying step S06, a second aging treatment is performed to precipitate fine deposits such as Cr-based precipitates and Zr-based precipitates.
Here, the aging treatment is performed under conditions of, for example, 400 ° C. or more and 530 ° C. or less and 0.5 hour or more and 5 hours or less.
The heat treatment method during the aging treatment is not particularly limited, but it is preferably performed in an inert gas atmosphere. Further, the cooling method after the heat treatment is not particularly limited, but it is preferably performed by water cooling.
Through such a process, the casting mold material according to the present embodiment is manufactured.

According to the casting mold material of the present embodiment configured as described above, Cr is 0.3 mass% or more and less than 0.5 mass%, Zr is 0.01 mass% or more and 0.15 mass% or less, and the remainder In the second aging treatment step S07, Cr (Zr) -based and Zr-based precipitates are finely precipitated to improve strength (hardness) and electrical conductivity. Can do.
And in the molding material for casting which concerns on this embodiment, since it has the acicular precipitate or plate-shaped precipitate containing Cr, a granular precipitate is formed at the time of slow cooling after the thermal spraying process step S06. The second aging treatment step S07 after the spraying treatment step S06 can sufficiently disperse fine precipitates, and the precipitation strengthening mechanism can sufficiently improve the strength (hardness). it can.

Further, the casting mold material according to the present embodiment further includes one or more elements selected from Fe, Si, Co, and P in total of 0.01 mass% or more and 0.15 mass% or less. Therefore, the formation of granular precipitates during the slow cooling after the thermal spraying process S06 is suppressed. Therefore, by the second aging treatment step S07 after the thermal spraying treatment step S06, fine precipitates can be sufficiently precipitated, and the strength (hardness) and conductivity can be improved reliably.

Furthermore, in the Cu—Cr—Zr alloy material according to the present embodiment, when it is held at 800 ° C. after being subjected to the complete solution treatment, the holding time until the conductivity becomes 55% IACS is 25 sec or more. Therefore, even if it is a case where it anneals after heating to the high temperature range of about 1000 degreeC in the thermal spraying process step S06, the solid solution amount of Cr and Zr is securable. Therefore, in the second aging treatment step S07 after slow cooling, Cr-based and Zr-based precipitates can be dispersed, and the strength (hardness) and conductivity can be improved. The “complete solution treatment” is a heat treatment for completely dissolving the alloy elements contained in the alloy material in the Cu matrix. In the case of the Cu—Cr—Zr alloy material according to the present embodiment, a heat treatment in which it is rapidly cooled after being held at a temperature of 950 to 1050 ° C. for 0.5 to 3.0 hours is given as an example.

In the Cu—Cr—Zr alloy material according to the present embodiment, the conductivity (% IACS) after cooling at 1000 ° C. to 600 ° C. after cooling at 1000 ° C. for 1 hour is 10 ° C./min. A, and when the conductivity (% IACS) after being held at 500 ° C. for 3 hours is B, since B / A> 1.1, there is a relationship of about 1000 ° C. in the thermal spraying process S06, for example. Even in the case of slow cooling after heating to a high temperature region, the electrical conductivity is improved in the second aging treatment step S07 after slow cooling, and the strength (hardness) is improved by precipitation hardening. Can do.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
In the present embodiment, it has been described that one or more elements selected from Fe, Si, Co, and P are included in total in a range of 0.01 mass% to 0.15 mass%, but the present invention is limited to this. There is no need to intentionally add these elements.

Below, the result of the confirmation experiment performed in order to confirm the effect of this invention is demonstrated.
A copper raw material made of oxygen-free copper having a purity of 99.99 mass% or more was prepared, charged into a carbon crucible, and melted in a vacuum melting furnace (vacuum degree 10 ⁻² Pa or less) to obtain a molten copper. Various additive elements were added to the obtained molten copper to prepare the component compositions shown in Table 1, and after maintaining for 5 minutes, the molten copper alloy was poured into a cast iron mold to obtain an ingot. The size of the ingot was about 80 mm in width, about 50 mm in thickness, and about 130 mm in length.
In addition, the raw material of Cr, which is an additive element, was used with a purity of 99.99 mass% or more, and the raw material of Zr was a purity of 99.95 mass% or more.

Next, after performing a homogenization process at 1000 ° C. for 1 hour in an air atmosphere, hot rolling was performed. The rolling reduction during hot rolling was 80%, and a hot rolled material having a width of about 100 mm, a thickness of about 10 mm, and a length of about 520 mm was obtained.
Using this hot-rolled material, a solution treatment was performed at 1000 ° C. for 1.5 hours, followed by water cooling.
Next, a first temporary treatment was performed at 480 (± 15) ° C. for 3 hours. Thus, a Cu—Cr—Zr alloy material was obtained.

Next, the obtained Cu—Cr—Zr alloy material was heat-treated at 1000 ° C. for 1 hour by simulating thermal spraying treatment, and then gradually cooled at a cooling rate of 10 ° C./min or less.
Thereafter, a second aging treatment was performed at 480 (± 15) ° C. for 3 hours. Thereby, a molding material for casting was obtained.

The obtained Cu—Cr—Zr alloy material is subjected to a complete solution treatment (1000 ° C., 1.5 hours) and then held at 800 ° C. until the conductivity reaches 55% IACS (T TT measurement), Vickers hardness (rolled surface), and conductivity were evaluated.
The obtained Cu—Cr—Zr alloy material was kept at 1000 ° C. for 1 hour and then cooled at a cooling rate of 1000 ° C. to 600 ° C. with a cooling rate of 10 ° C./min. The conductivity B (% IACS) after being held at 500 ° C. for 3 hours was measured, and the conductivity ratio B / A was evaluated.

Furthermore, the Vickers hardness (rolled surface) and conductivity of the casting mold material after the thermal spraying treatment and after the second aging treatment were evaluated. Furthermore, the structure was observed, and the presence or absence of needle-like precipitates or plate-like precipitates containing Cr was evaluated.

(Composition analysis)
The component composition of the obtained Cu—Cr—Zr alloy material and casting mold material was measured by ICP-MS analysis (inductively coupled plasma mass spectrometry). The measurement results are shown in Table 1.

(T.T.T. measurement)
A test piece of Cu—Cr—Zr alloy material that was completely solution-treated was held at 800 ° C., and the conductivity was measured after a predetermined time, and the time for the conductivity to reach 55% IACS was evaluated. The evaluation results are shown in Table 2.
In addition, about the example 2 of this invention and the comparative example 4, the same evaluation is performed also at temperatures other than 800 degreeC, and the time which electrical conductivity reaches 55% IACS and 60% IACS in each temperature is evaluated, and it shows in FIG. T.A. T. T. et al. T. T. et al. A curve was created.

(Tissue observation)
A sample for observation is collected from the obtained casting mold material after the thermal spraying treatment, and the structure is observed with a scanning electron microscope after the polishing treatment to confirm the presence or absence of needle-like precipitates or plate-like precipitates containing Cr. did. The observation results are shown in Table 3. In the observation field of 50 μm × 60 μm, when five or more precipitates having an aspect ratio (long side / short side) of 3 or more were observed, it was judged that needle-like precipitates or plate-like precipitates were present. Whether the observed acicular precipitate or plate-like precipitate contains Cr was determined by elemental mapping.
Moreover, about the sample of this invention example 2 and the comparative example 4, after (a) 1st temporary treatment, (b) After thermal spraying and slow cooling, (c) The result of having observed structure | tissue after 2nd aging treatment (structure | tissue observation) The photograph is shown in FIG. Furthermore, the observation results of needle-like precipitates or plate-like precipitates containing Cr observed in Invention Example 2 after the second aging treatment ((a) microstructure observation photograph, (b) surrounded by white lines in (a)) FIG. 4 shows an enlarged view of the portion, (c) the element mapping result of Zr in (b), and (d) the element mapping result of Cr in (b)).

(Vickers hardness measurement)
According to JIS Z 2244, the Vickers hardness tester manufactured by Akashi Co., Ltd. was used to measure the Vickers hardness at 9 locations on the test piece as shown in FIG. The average value of was obtained. Table 2 shows the measurement results of the Cu—Cr—Zr alloy material, and Table 3 shows the measurement results of the casting mold material after the thermal spraying treatment and after the second aging treatment.

(Conductivity measurement)
Using SIGMA TEST D2.068 (probe diameter φ6 mm) manufactured by Nippon Ferster Co., Ltd., the conductivity at the center of the cross section of the 10 × 15 mm sample was measured three times, and the average value was obtained. Table 2 shows the measurement results of the Cu—Cr—Zr alloy material, and Table 3 shows the measurement results of the casting mold material after the thermal spraying treatment and after the second aging treatment.

As shown in Tables 1 and 2, the Cu—Cr—Zr alloy material of the example of the present invention has a holding time until the conductivity becomes 55% IACS when held at 800 ° C. after the complete solution treatment. Was confirmed to be 25 sec or longer. Here, as shown in FIG. T.A. T.A. When the curve is confirmed, in Example 2 of the present invention, the time required to reach 55% IACS and 60% IACS is shifted to a longer time side compared to Comparative Example 4, and the precipitation of Cr-based and Zr-based precipitates occurs. It was confirmed that it was suppressed.

Further, as shown in Table 3, it was confirmed that the casting mold material of the present invention example had needle-like precipitates or plate-like precipitates containing Cr. And in the casting mold material of the example of the present invention, it was confirmed that the Vickers hardness and the conductivity were greatly increased by the second aging heat treatment as compared with the comparative example.

Further, as a result of the structure observation, in Comparative Example 4, as shown in FIG. 3, no acicular precipitates or plate-like precipitates containing Cr were observed in the specimen slowly cooled after the thermal spraying treatment, and granular precipitates were observed. Was observed.
On the other hand, in Example 2 of the present invention, as shown in FIG. 3, needle-like precipitates or plate-like precipitates containing Cr were observed in the test pieces that were gradually cooled after the thermal spraying treatment.
In addition, as a result of magnifying the precipitate of the test piece after the second aging heat treatment of Example 2 of the present invention, as shown in FIG. 4, Cr was detected from the acicular precipitate or the plate-like precipitate, and granular From these precipitates, Cr and Zr were detected.

According to the casting mold material of the present invention, even if it is gradually cooled after the thermal spraying treatment, the strength (hardness) and electrical conductivity can be sufficiently improved by the subsequent aging treatment. Therefore, the molding material for casting of the present invention is suitable for casting of steel materials and the like.

Claims

A casting mold material used when casting a metal material,
Cr has a composition composed of 0.3 mass% or more and less than 0.5 mass%, Zr 0.01 mass% or more and 0.15 mass% or less, and the balance consisting of Cu and inevitable impurities,
A casting mold material comprising a needle-like precipitate or a plate-like precipitate containing Cr.
The casting mold material according to claim 1, further comprising one or more elements selected from Fe, Si, Co, and P in a total amount of 0.01 mass% to 0.15 mass%. .
Cr has a composition composed of 0.3 mass% or more and less than 0.5 mass%, Zr 0.01 mass% or more and 0.15 mass% or less, and the balance consisting of Cu and inevitable impurities,
A Cu—Cr—Zr alloy material characterized in that when it is held at 800 ° C. after being subjected to a complete solution treatment, the holding time until the electric conductivity becomes 55% IACS is 25 sec or more.
The Cu—Cr— according to claim 3, further comprising one or more elements selected from Fe, Si, Co, and P in a total amount of 0.01 mass% to 0.15 mass%. Zr alloy material.
Conductivity (% IACS) after holding at 1000 ° C for 1 hour and cooling at 1000 ° C to 600 ° C at a cooling rate of 10 ° C / min, and then holding at 500 ° C for 3 hours (% IACS) 5. The Cu—Cr—Zr alloy material according to claim 3 or 4, wherein a relationship of B / A> 1.1 is satisfied when B) is B.