JP2002180158A - Chromium-zirconium base copper alloy for continuous casting mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chromium-zirconium base copper alloy for continuous casting mold and the continuous casting mold composed of this copper alloy. SOLUTION: The continuous casting mold has the composition of 0.1-1.5 mass% Cr, 0.01-0.25 mass% Zr, 0.01-0.3 mass% Si and the balance Cu with inevitable impurities, and the structure uniformly dispersing the compound of Cr and Si in the matrix.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromium-zirconium-based copper alloy for a continuous casting mold and a continuous casting mold made of the copper alloy.

[0002]

2. Description of the Related Art In general, chromium-zirconium-based copper alloys are used as materials for continuous casting molds because of their excellent heat resistance, thermal conductivity, high-temperature wear resistance, and electrical conductivity. I have. A plate made of this chromium-zirconium-based copper alloy is usually obtained by continuous casting or semi-continuous casting: Cr: 0.1-1.5% by mass, Zr: 0.01-
A chromium-zirconium-based copper alloy ingot having a composition containing 0.25% by mass is heated to 700 ° C. or higher, then hot worked, then heated to a range of 920 to 1000 ° C. and rapidly cooled with water to be subjected to a solution treatment. , Then 400-5
It is known to manufacture by performing aging treatment at a temperature of 20 ° C. for 0.5 to 5 hours.

[0003] The chromium-zirconium-based copper alloy sheet thus obtained is cut and processed to a predetermined size, and if necessary, the surface is plated with Ni or the like, and assembled into a continuous casting mold.

[0004]

However, the conventional Cr:
A chromium-zirconium-based copper alloy having a composition containing 0.1 to 1.5% by mass and Zr: 0.01 to 0.25% by mass has insufficient high-temperature strength, heat resistance and high-temperature wear resistance. The continuous casting mold made of this conventional chromium-zirconium-based copper alloy has problems such as abrasion progresses as the number of continuous casting increases, the dimensional accuracy of the continuous casting mold decreases, and it tends to be deformed. Further, a chromium-zirconium-based copper alloy having excellent high-temperature wear resistance is required.

[0005]

Means for Solving the Problems Accordingly, the present inventors have:
From such a viewpoint, a study was conducted to obtain a chromium-zirconium-based copper alloy having more excellent high-temperature strength and high-temperature wear resistance without deteriorating properties such as thermal conductivity and electric conductivity. 0.1-1.5% by mass, Z
r: 0.01 to 0.25% by mass, the balance being made of a chromium-zirconium-based copper alloy having a composition consisting of Cu and unavoidable impurities, containing Si: 0.01 to 0.3% by mass. A chromium-zirconium-based copper alloy that has a structure in which compound particles of Cr and Si are uniformly dispersed in an alloy base has high-temperature strength and high-temperature hardness without deterioration in properties such as thermal conductivity and electrical conductivity. The continuous casting mold made of a chromium-zirconium-based copper alloy that has been further improved and has excellent high-temperature strength and high-temperature hardness has better hot-temperature strength and higher-temperature hardness, so that high-temperature wear resistance is further improved. However, they have found that the life of the continuous casting mold is greatly extended.

The present invention has been made based on such findings, and (1) Cr: 0.1 to 1.5% by mass;
Zr: 0.01 to 0.25 mass%, Si: 0.01 to
A chromium-zirconium-based copper alloy for a continuous casting mold having a composition of 0.3 mass% and the balance: Cu and inevitable impurities, (2) Cr: 0.1 to 1.5 mass%, Z
r: 0.01 to 0.25% by mass, Si: 0.01 to 0.
3% by mass, the balance being: a chromium-zirconium-based copper alloy for a continuous casting mold having a composition of Cu and unavoidable impurities and having a structure in which compound particles of Cr and Si are dispersed in a base material. It has.

The chromium-zirconium-based copper alloy for a continuous casting mold of the present invention has an excellent effect particularly as a continuous casting mold. Therefore, the present invention is characterized by (3) a continuous casting mold made of the chromium-zirconium-based copper alloy according to the above (1) or (2).

In order to produce a chromium-zirconium-based copper alloy for a continuous casting mold having the component composition and structure of the present invention, electrolytic copper having a purity of 99.99% or more is dissolved to form an electrode having an oxygen concentration of 2 ppm or less. A low-oxygen pure copper melt is prepared, and a chromium-zirconium-based copper alloy melt containing these components is prepared by adding Cr, Zr and Si to this extremely low-oxygen pure copper melt, and the chromium-zirconium-based copper alloy melt is continuously produced. An ingot is produced by casting, and a chrome-zirconium-based copper alloy
C. or more, and hot working is performed at this temperature to destroy the cast structure to obtain a worked structure.
The solution can be manufactured by performing a solution treatment by heating to a temperature of 00 ° C. and then rapidly cooling with water, and then performing an aging treatment at a temperature of 400 to 520 ° C. for 0.5 to 5 hours.

In order to produce a chromium-zirconium-based copper alloy for a continuous casting mold having the component composition and structure of the present invention, electrolytic copper is melted in vacuum to produce a very low oxygen pure copper melt having an oxygen concentration of 2 ppm or less. is necessary. When the oxygen concentration exceeds 2 ppm, Si reacts with oxygen first to form silicon oxide, and the amount of the compound of Cr and Si decreases, and the amount of the particles of the compound of Cr and Si dispersed in the substrate decreases. Therefore, a continuous casting mold having sufficient high-temperature strength and high-temperature wear resistance cannot be obtained because sufficient high-temperature strength and high-temperature hardness cannot be obtained. Chrome of the present invention
The smaller the particle size of the compound particles of Cr and Si dispersed in the body of the zirconium-based copper alloy is, the higher the high-temperature strength is, the more preferable it is. The compound particles of Cr and Si dispersed in the matrix of the chromium-zirconium-based copper alloy of the present invention are mostly composed of an intermetallic compound of Cr and Si, but are formed by reacting with a trace amount of oxygen. And a complex oxide of Si and Si.

The reason why the composition of the chromium-zirconium-based copper alloy for a continuous casting mold of the present invention is limited as described above will be described.

[0011] Cr: Cr has the effect of improving the high-temperature strength by precipitation hardening, but if its content is less than 0.1% by mass, a sufficient effect cannot be obtained. As a result, the crystallized grains become coarser and increase, so that further high-temperature strength cannot be obtained, and the thermal conductivity is rather lowered, which is not preferable. Therefore, Cr: 0.1 to 1.5
% By mass. A more preferable range of the Cr content is 0.1.
3 to 1.0% by mass.

Zr: Like Cr, Zr has the effect of improving the high-temperature strength by precipitation hardening, but if its content is less than 0.01% by mass, the desired effect cannot be obtained.
If Zr exceeds 0.25% by mass, further high-temperature strength cannot be obtained, and the thermal conductivity is rather lowered, which is not preferable.
Therefore, Zr was set to 0.01 to 0.25% by mass. A more preferable range of the Zr content is 0.01 to 0.1.
5% by mass.

Si: Si forms a compound with Cr when added to improve high-temperature strength and high-temperature hardness,
Therefore, the chromium-zirconium-based copper alloy has an effect of improving the high-temperature strength and the high-temperature hardness of the alloy. However, if the content is less than 0.01% by mass, a sufficient effect cannot be obtained. %, The content of Si is reduced from 0.01 to 0.3 because the thermal conductivity is impaired.
% By mass. A more preferable range of the Si content is 0.1.
It is from 0.01 to 0.20% by mass.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Purity: An electrolytic copper cathode having a purity of 99.99% or more is vacuum-dissolved to obtain an oxygen concentration of 2 pp.
m of ultra-low oxygen pure copper melt of less than
By adding Zr and Si, the chromium-zirconium-based copper alloy of the present invention having the component composition shown in Table 1 (hereinafter, referred to as "
A molten metal comprising 1 to 10 (referred to as a copper alloy of the present invention)
The thickness of the obtained molten metal is 260 m by continuous casting.
A plate-like ingot having a dimension of mx width: 640 mm was manufactured. The obtained plate-like ingot is hot-rolled at 800 ° C. to prepare a plate having a size of thickness: 50 mm × width: 980 mm, and the plate is heated to 950 ° C. and then rapidly cooled with water to perform a solution treatment. And then at 450 ° C for 3
Aging treatment was performed by holding for a time.

Further, for comparison, purity: 99.99
% Of pure copper having a purity of not less than 5% by vacuum melting to prepare a normal low oxygen pure copper melt having an oxygen concentration of 5 ppm, and adding Cr and Zr to the melt to obtain a conventional chromium having a component composition shown in Table 1. A melt made of a zirconium-based copper alloy (hereinafter, referred to as a conventional copper alloy) is produced, and the obtained melt is continuously cast to have a thickness of 260 mm.
X Width: A plate-shaped ingot having a size of 640 mm was manufactured. The obtained plate-like ingot is hot-rolled at 800 ° C. to prepare a plate having dimensions of a thickness: 50 mm and a width: 980 mm. The plate is heated to 950 ° C., and then rapidly cooled with water to perform a solution treatment. And then aged by holding at 450 ° C. for 3 hours.

With respect to the obtained sheets of the copper alloys 1 to 10 of the present invention and the conventional copper alloy, the presence or absence of Cr and Si compound particles in the alloy body was measured by a transmission electron microscope, and the results are shown in Table 2. Further, the sheet materials of the copper alloys 1 to 10 of the present invention and the conventional copper alloy are set at room temperature (25 ° C.), 200 ° C., and 4 ° C.
Tensile tests were performed at 00 ° C. and 600 ° C., and the tensile strength, 0.2% proof stress, and Vickers hardness at each temperature were measured. The results are shown in Table 2. In addition,
The test piece used in the tensile test is cut from the plate
IS-G-0567 Type II test piece was prepared and JIS-G
A tensile test was carried out according to -0567 "Method of high-temperature tensile test of steel materials and heat-resistant alloys".

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

As is clear from the results shown in Tables 1 and 2, the copper alloys 1 to 10 of the present invention are superior in high-temperature strength and high-temperature hardness to the conventional copper alloys. Therefore, the continuous casting mold composed of the chromium-zirconium-based copper alloy of the present invention has excellent high-temperature strength and high-temperature wear resistance, greatly extends its life, and can greatly contribute to the development of the steel industry. It is.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shoji Aoki 1-297 Kitabukurocho, Omiya-shi, Saitama F-term in Mitsubishi Materials Real Research Institute (reference) 4E004 AA10

Claims (3)

[Claims] (1) Cr: 0.1 to 1.5% by mass, Zr: 0.
01 to 0.25% by mass, Si: 0.01 to 0.3% by mass
A chromium-zirconium-based copper alloy for a continuous casting mold, characterized by having a composition consisting of Cu and inevitable impurities. 2. Cr: 0.1-1.5% by mass, Zr: 0.
01 to 0.25% by mass, Si: 0.01 to 0.3% by mass
And a balance: a chromium-zirconium-based copper alloy for a continuous casting mold, characterized by having a composition comprising Cu and unavoidable impurities, and having a structure in which compound particles of Cr and Si are dispersed in a base material. 3. A continuous casting mold made of the chromium-zirconium-based copper alloy according to claim 1.