JP2000064060A - Member for nonferrous molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for nonferrous molten metal having erosion resistance even in the case of being immersed in or repeatedly brought into contact with nonferrous molten metal and safely usable by using a ferrous material as a base material. SOLUTION: On the surface of a ferrous base material 1, an intermediate layer 2 of an Al-Fe alloy metallically bonded to the ferrous base material surface is formed, and, moreover, the surface of the intermediate layer 2 of the Al-Fe alloy is coated with a ceramic layer 3. The ceramic layer 3 contains flat ceramic powder, is bonded with fused glass or bonded with a ceramic bonding material essentially consisting of silicate or phosphate and is fused to cover on the Al-Fe alloy layer as the substrate. The flat ceramic powder is composed of the powder of one or >= two kinds among silicon carbide flat alumina and mica and is contained by 20 to 70 wt.% in the ceramic layer. As the nonferrous molten metal, mainly, the molten metal of an aluminum alloy, a zinc alloy, a copper alloy or the like is used as the object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melt-resistant member for melting or casting equipment for producing non-ferrous metal products, and particularly to non-ferrous metals such as aluminum alloys, zinc alloys and copper alloys. On the other hand, it relates to a suitable member for molten metal.

[0002]

2. Description of the Related Art There are two types of non-ferrous metal members for molten metal which are in contact with the molten metal and which are in contact with the molten metal without being immersed. For example, there are a thermocouple protection tube and a stalk as a member to be dipped in the molten metal, and a ladle and a gutter as a member to be repeatedly in contact with the molten metal. Conventionally, cast iron materials having a surface coated with a mold coating material have been generally used for these parts. In recent years, the application of sialon ceramics has been expanding instead of this.

Further, as an example of a molten metal member having a coating layer formed on the surface for the same purpose as that of the present invention, JP-A-49-5422 is used.
Japanese Patent Publication 9 describes a casting tool in which a complex oxide film is formed on the surface of an iron-based material containing Cr and Al. In addition, although the use is not specified, in Japanese Patent Publication No. 7-5392, a fine particle metal oxide or an organic metal binder is formed on a bonding layer formed by reacting an oxide film of an iron-based material with a silicate. A ceramic / iron member joined body is described, which has an iron oxide diffusion-preventing layer formed by quenching and is suggested to be used for exposure to high temperature corrosive exhaust gas.

[0004]

The molten metal member using the conventional cast iron material coated with the mold coating material is not only not only corroded little by little by the peeled portion of the mold coating material reacting with the molten metal, but also melted and damaged. Fe, which is the main component, melts into the molten metal and deteriorates the mechanical properties of the cast product. Sialon ceramics, which have been widely applied in recent years, do not react with the molten metal and are therefore suitable as members for molten metal. Since it has a certain degree of toughness as compared with conventional ceramics, satisfactory results are obtained depending on the application. However, since it does not essentially exceed the range of ceramic materials and is weaker than metal materials, it has a drawback that it is easily damaged and difficult to handle. In addition, since it is expensive, it cannot be applied easily.

In order to solve the above problems, the above-mentioned JP-A-4
In addition to 9-54229 and Japanese Patent Publication No. 7-5392, various heat resistances in which a coating layer is formed on the surface of an iron-based material,
Corrosion- and corrosion-resistant members are provided. Also in the present invention, in order to solve the above problems, similarly using an iron-based material, durable even after immersion contact or repeated contact with a non-ferrous metal molten metal, and to provide a member for molten metal that can be used safely To do.

[0006]

The first invention of the present invention is, as shown in the schematic cross-sectional view of the surface layer portion of the molten metal member of the present invention of FIG. 1, the iron-based material on the surface of the iron-based material substrate 1. An Al-Fe alloy layer 2 that is metallically bonded to the base material 1 is formed, and further Al-
The non-ferrous metal has a structure in which the surface of the Fe alloy layer 2 is covered with the ceramic layer 3, and the ceramic layer 3 contains flat ceramic powder, is bonded by molten glass, and is fused to the Al-Fe alloy layer 2. It is a member for molten metal.

In the research for completing the present invention, it has been found that interposing an intermediate layer of Al--Fe alloy is effective for securing the adhesion of the ceramic layer. Al
In order to form the —Fe alloy layer, it is necessary to use an iron-based material as an Fe source for the base material. Since the Al—Fe alloy layer itself is a metal and is metallically bonded to the base iron-based material substrate, cracks and peeling are unlikely to occur. And A
The Fe component contained in the l-Fe alloy layer seems to be effective in obtaining the adhesion of the ceramic layer coating the surface of the Al-Fe alloy layer. Further, the flat ceramic powder contained in the ceramic layer is laminated in a layered form and spreads in the direction of the flat surface, so that the particles are mixed in the free direction, so that the bonding property is improved.

Generally, when a member for molten metal melts,
Under the thermal load of immersion contact or repeated contact with the molten metal, fine cracks and peeling occur in the coating layer, the molten metal enters the cracks and peeling parts and begins to erode the base, and finally It is thought to cause a large amount of erosion. Even when such a situation is encountered, the non-ferrous metal melt member of the present invention is unlikely to cause cracks or peeling due to the above-described actions. Then, the non-ferrous metal melt member is less likely to be melt-damaged by the intrusion of the melt, and can be safely used.

In the second and third inventions, the flat ceramic powder contained in the ceramic layer of the first invention is composed of one or more powders of silicon carbide, flat alumina, and mica. The flat ceramic powder is 20 to 70% by weight of the ceramic layer. Then, by defining the flat ceramic in the ceramic layer to be coated as the outermost surface layer in an appropriate component and amount, a more effective molten metal member can be obtained.

In a fourth aspect of the invention, an Al-Fe alloy layer 2 that is metallically bonded to the surface of the iron-based material base material 1 is formed on the surface of the iron-based material base material 1 shown in the schematic cross-sectional view of FIG. , And Al-
The structure is the same as that of the first invention in which the surface of the Fe alloy layer 2 is covered with the ceramic layer 3 containing the flat ceramic powder. However, the ceramic layer is a member for molten non-ferrous metal, which is bonded to the Al—Fe alloy layer 2 by being bonded by a ceramic binder containing silicate or phosphate as a main component. Then, an effect equivalent to that of the first invention in which the ceramic layer 3 containing the flat ceramic powder is bonded by the molten glass is obtained.

The fifth and sixth inventions specify the components and amounts of the flattened ceramic powder in the ceramic layer of the fourth invention. The same definition as the second and third inventions makes the fourth invention more effective.

In the seventh to ninth inventions, the material of the applied non-ferrous metal melt in the first to sixth inventions is aluminum alloy,
It is specific to zinc alloys and copper alloys.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The base material of the molten metal member of the present invention is Al
-It is limited to iron-based materials such as ordinary carbon steel, alloy steel, ordinary cast iron, and alloy cast iron that serve as an Fe source for forming the Fe alloy layer, and the entire material can be used, but the material details are not specified. The Al—Fe alloy layer is formed on these iron-based material substrates by a hot dip aluminum plating method, an aluminum infiltration method, or the like. In the case of the molten aluminum plating method, in order to make the aluminum plating layer an Al-Fe alloy, for example, it is heated to 760 to 800 ° C for 1 to 3 hours to diffuse the Fe component from the iron-based material base material to the aluminum plating layer, It is an Al-Fe alloy layer. In the case of the aluminum infiltration method, the area infiltrated with aluminum itself is Al-Fe.
Since it is an alloy layer, heating for diffusing aluminum is unnecessary. The Al—Fe alloy layer prepared as described above has a thickness of 50 to 200 μm and Fe of 30 to 70% by weight.

As the flat ceramic powder, powders of silicon carbide, flat alumina, mica and the like can be used. The amount of the flat ceramic powder is preferably 20 to 70% by weight in the ceramic layer, and the size is such that the major axis is 2
˜100 μm, and the ratio of major axis to thickness is preferably 5 or more.
The powder itself of silicon carbide and mica is essentially flat, and most of the powders are in the size range described above, and can be used as they are. Alumina must be prepared as a powder within the above size range.

As the binder in the ceramic layer, a high temperature molten glass forming material, or a silicate solution or a phosphate solution is used. As the silicate solution, one or a mixture of two or more of sodium silicate, potassium silicate, and lithium silicate aqueous solution can be used, and as the phosphate solution, aluminum phosphate aqueous solution can be used. For the silicate solution or phosphate solution, MgO, Z as a curing agent
You may add oxides, such as nO, suitably. The binder in the ceramic layer is 10 to 80% by weight [excluding water]
It is preferable to include. In the ceramic layer, the balance of the total amount of the flat ceramic powder and the binder is usual oxides such as alumina, zirconia, and silica, carbides such as silicon carbide, nitrides such as silicon nitride, and unavoidable impurities.

When coating the ceramic layer, a mixed slurry of the flat ceramic powder and the binder is used as the base Al-
It is applied to the surface of the Fe alloy layer and dried. When a high temperature molten glass forming material is used as the binder, it is mixed with a solvent such as water to form a slurry. After coating and drying, the glass is heated to the melting temperature and fused to the base. When a silicate solution or a phosphate solution is used as the binder, at least the temperature at which water of crystallization disappears after coating and drying, that is, about 5
Heat to 00 ° C. or higher to fuse. The thickness of the ceramic layer thus formed is preferably 100 to 500 μm. If the thickness is less than 100 μm, the melting loss resistance against the molten metal is small, and if it exceeds 500 μm, peeling easily occurs due to thermal shock or the like.

[0017]

Example 1 The test pieces of various iron-based material substrates shown in Table 1 were examined for erosion resistance to molten aluminum alloy. First, the diameter 2
A round bar test piece material having a length of 0 mm and a length of 200 mm was subjected to hot-dip aluminum plating to form an aluminum coating layer having a thickness of 50 μm. The test piece material having this coating layer is
The aluminum coating layer was turned into an Al-Fe alloy layer by heating the aluminum coating layer for 3 hours at 0 ° C. Separately, 30% by weight of silicon carbide powder having a particle size of 10 μm, 10% by weight of flat alumina having a particle size of 80 μm, and 60% by weight of a molten glass forming material were mixed to prepare a ceramic layer forming material slurried with water. The composition of the molten glass forming material is 30% by weight of SiO ₂ ,
B ₂ O ₃ 25% by weight, CaO 20% by weight, Na ₂ O13
% By weight and K ₂ O 12% by weight. A round bar test piece material coated with an Al-Fe alloy layer was immersed in this slurry,
The slurry was applied to the entire surface. Room temperature drying, 110 ℃
After drying, the molten glass forming material was melted by heating at 650 ° C. for 1 hour, and was fused to the underlying Al—Fe alloy layer to form a coating on the ceramic layer. This coated ceramic layer has a gray color and a thickness of approximately 200 to 300 μm.
Met.

A total of 8 pieces of the test pieces coated with the present invention of the four types of iron-based base materials shown in Table 1 and the conventional test pieces prepared only for coating, which were prepared for comparison, are shown in FIG. It tested using the melt-dissipation test apparatus. Each of the test pieces 4 was attached to eight places around a circular test piece holding plate 6 having a diameter of 200 mm so that the portion from the tip to 80 mm was immersed in the molten aluminum alloy 5 as one example. Aluminum alloy [ADC12] molten metal 5 kept at 750 ° C
The test piece was immersed for a period of time to examine the melting damage state of each test piece. Table 1 shows the condition of each test piece. The numerical values in the table are values in which the diameter of the test piece decreased due to melting damage. From this result, it is clear that the coating of the present invention has excellent erosion resistance to the molten aluminum alloy.

[0019]

[Table 1]

Example 2 With respect to a test piece having the same size as the base material of the same iron-based material as in Example 1, the corrosion resistance to molten zinc alloy was examined. First, an Al—Fe alloy layer having a thickness of 100 μm was formed on the surface of each round bar test piece material by the aluminum infiltration method. Apart from
30% by weight of silicon carbide powder having a particle size of 10 μm, 20% by weight of mica, 50% by weight of an aqueous sodium silicate solution having a concentration of 30% by weight
Was mixed to prepare a slurry-forming ceramic layer forming material. A round bar test piece material coated with an Al-Fe alloy layer was immersed in this slurry to apply the slurry to the entire surface. After drying at room temperature and further at 350 ° C., it was heated to 650 ° C. and fused to the underlying Al—Fe alloy layer to form a ceramic layer as a coating. The thickness of the coated ceramic layer was approximately 300 μm.

A total of 8 pieces of the test pieces coated with the present invention of the same four types of iron-based base materials as in Example 1 and the conventional test pieces prepared only for coating, which were prepared for comparison, were prepared. As in Example 1, the test was carried out by mounting on the melting test apparatus of FIG. The zinc alloy [ZDC1] molten metal 5 kept at 650 ° C. was immersed in the molten metal 5 for 20 hours, and the erosion state of each test piece was examined. Table 2 shows the condition of each test piece. The numerical values in the table are values in which the diameter of the test piece decreased due to melting damage. From this result, it is clear that the coating of the present invention has a melt damage resistance effect on the molten zinc alloy.

[0022]

[Table 2]

Example 3 The test pieces of the stainless steel base material shown in Table 3 were examined for erosion resistance to molten copper alloy [brass]. First, the diameter 2
A round bar test piece material having a length of 0 mm and a length of 200 mm was subjected to hot-dip aluminum plating to form an aluminum coating layer having a thickness of 50 μm. The test piece material having this coating layer is
The aluminum coating layer was changed to an Al—Fe alloy layer by heating the diffusion treatment at 0 ° C. for 1 hour. Further, the ceramic layer covering the surface was formed by the same treatment with the same composition as in Example 1. The thickness of this coated ceramic layer is approximately 3
It was 00 μm.

The above-prepared stainless steel coated test pieces of the present invention and the conventional uncoated test pieces prepared for comparison without comparison were tested. Each test piece was immersed in a molten brass [YBsC3] held at 1100 ° C. for 2 hours at a portion from the tip to 80 mm, and the melt damage state was examined. The situation is shown in Table 3. It is clear that the coating of the present invention also has a melt loss resistance effect on the molten copper alloy.

[0025]

[Table 3]

Example 4 A coating of the present invention was applied to a ladle of an aluminum alloy die casting facility by test. Normal cast iron for a capacity of 2 kg [FC20
0] ladle material is subjected to hot dip aluminum plating,
Form an aluminum coating layer with a thickness of 50 μm, and
The aluminum coating layer is heated to 60 ° C. for 3 hours to form an Al layer.
-Fe alloy layer. Separately, 22% by weight of silicon carbide powder having a particle size of 10 μm, 38% by weight of flat alumina having a particle size of 80 μm, and 40% by weight of a molten glass forming material were mixed to prepare a slurry-forming ceramic layer forming material. The composition of the molten glass forming material is SiO ₂ 30% by weight, B ₂ O ₃ 25% by weight, C
aO20 _wt%, Na 2 O13 _wt%, a K 2 O12 wt%. A ladle material coated with an Al—Fe alloy layer was dipped in this slurry to apply the slurry to the entire surface.
After being dried at room temperature and further dried at 350 ° C., it was heated to 650 ° C. to melt the molten glass forming material and fuse it to the underlying Al—Fe alloy layer to form a ceramic layer as a coating. The thickness of the coated ceramic layer was approximately 300 μm.

The ladle coated with the present invention prepared as described above was roughly
It was continuously used for 60 days for drawing up the molten aluminum alloy [ADC12] at 50 ° C. With this use
After being repeatedly contacted with the molten metal for a total of 35,000 times and heated and cooled, the base material was sound, with no melting loss and no cracking or peeling on the molten metal contact surface. In addition, the molten metal contact surface was relatively smooth and there was little adhesion of slag, and the slag that adhered could be easily removed. On the other hand, a conventional cast iron ladle that has not been coated and has been used only for the conventional coating type has been maintained and coated daily, but it seems that there was a little erosion every day, even for a week. When it was used, melting damage of about 1 mm per piece had occurred on the inner surface near the pouring port. From this, it is clear that the ladle coated with the present invention has a remarkable erosion resistance effect and has no erosion loss, so that the Fe component does not melt into the molten metal and the quality of the aluminum alloy die cast product is improved.

Example 5 The coating of the present invention was applied to the stalk of an aluminum alloy low pressure casting facility. 100 μm thick on the surface of stalk material made of ordinary cast iron [FC200] with an outer diameter of 135 mm, an inner diameter of 100 mm and a length of 800 mm, by an aluminum infiltration method.
The Al-Fe alloy layer of was formed by coating. Separately, particle size 10μ
30% by weight of silicon carbide powder of m, 20% by weight of flat alumina having a particle size of 80 μm, and 50% by weight of an aqueous sodium silicate solution having a concentration of 30% by weight were mixed to prepare a slurry-forming ceramic layer forming material. The Stoke material coated with the Al—Fe alloy layer was dipped in this slurry to apply the slurry to the entire surface. After drying at room temperature and 350 ° C, 6
The ceramic layer was coated and formed by heating at 50 ° C. and fusing to the underlying Al—Fe alloy layer. The thickness of this coated ceramic layer was approximately 400 μm.

The stalk of the present invention prepared as described above was continuously immersed for 3 weeks in an aluminum alloy [AC4B] bath water at a temperature of about 750 ° C. in a molten metal holding furnace of a low pressure casting facility. As a result of removing the stalk and inspecting it, it was found that the base material was not melted and that the molten metal contact surface was not cracked or separated, and was sound. On the other hand, conventional cast iron stalks that have only been applied with a coating type that has not been used for coating have been maintained and coated daily, but after two weeks of use, the outer surface and the inner surface have a thickness of about 1 mm on each side. Melting was happening.
From this, the stalk of the coating of the present invention has a remarkable erosion resistance effect, and since there is no erosion loss, the Fe component does not melt into the molten metal and the quality of the aluminum alloy low-pressure cast product is improved.

INDUSTRIAL APPLICABILITY It is apparent that the non-ferrous metal melt member of the present invention is sound and has excellent erosion resistance when used in the melt of aluminum alloys, zinc alloys, and copper alloys according to Examples. is there. Further, since the melting resistance is good, the components of the base material do not dissolve in the molten metal, and the quality of the non-ferrous metal casting product is improved. Further, since the base material is an iron-based material, it is tough and inexpensive. These greatly contribute to the improvement of the maintenance work efficiency of the melting or casting equipment for manufacturing the non-ferrous metal products, the cost reduction, and the quality improvement of the non-ferrous metal products.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a surface layer portion of a molten metal member of the present invention.

FIG. 2 is a front explanatory view of a melting loss test apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1; Iron-based material substrate 2; Al-Fe alloy layer
3; ceramic layer 4; test piece 5; non-ferrous metal melt
6; Test piece holding plate 6a; Support shaft 7; Molten bath

Claims (9)

[Claims] 1. A structure in which an Al—Fe alloy layer that is metallically bonded to the surface of the substrate is formed on the surface of the substrate made of an iron-based material, and the surface of the Al—Fe alloy layer is covered with a ceramic layer. The ceramic layer contains flat ceramic powder, is bonded by molten glass, and is fused and bonded to the Al—Fe alloy layer. 2. The flat ceramic powder contained in the ceramic layer is one of silicon carbide, flat alumina, and mica.
The member for molten non-ferrous metal according to claim 1, characterized in that it comprises one kind or two or more kinds of powders. 3. The ceramic layer contains flat ceramic powder in an amount of 20 to 70% by weight.
Or the member for molten non-ferrous metal according to any one of 2 and 3. 4. A structure in which an Al—Fe alloy layer metallically bonded to the surface of the substrate is formed on the surface of the substrate made of an iron-based material, and the surface of the Al—Fe alloy layer is covered with a ceramic layer. The non-ferrous metal molten metal is characterized in that the ceramic layer contains flat ceramic powder, and is bonded by a ceramic binder containing silicate or phosphate as a main component and fused to the Al-Fe alloy layer. Element. 5. The flat ceramic powder contained in the ceramic layer is one of silicon carbide, flat alumina, and mica.
5. A member for molten non-ferrous metal according to claim 4, characterized in that it comprises one kind or two or more kinds of powders. 6. The ceramic layer contains flat ceramic powder in an amount of 20 to 70% by weight.
Or the member for molten non-ferrous metal according to any one of 5 and 5. 7. The non-ferrous metal melt member according to claim 1, wherein the non-ferrous metal melt is an aluminum alloy melt. 8. The member for molten non-ferrous metal according to claim 1, wherein the molten non-ferrous metal is a zinc alloy molten metal. 9. The non-ferrous metal melt member according to claim 1, wherein the non-ferrous metal melt is a copper alloy melt.