JP2845144B2 - Hot-dip metal bath immersion member and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten metal plating bath immersion member such as a sink roll and a support roll and a method for producing the same, and particularly to a molten metal plating such as molten zinc, molten aluminum, molten tin and molten zinc / aluminum alloy. The present invention relates to a hot-dip metal bath immersion member having excellent erosion resistance, foreign matter adhesion resistance and roll maintainability, and excellent thermal shock resistance to a bath, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, surface-treated steel sheets such as hot-dip metal-plated steel sheets having excellent corrosion resistance, weldability and paintability have been used in automobiles,
Demand for civil engineering, construction and home appliances is rapidly expanding. As a method for producing this surface-treated steel sheet, a continuous hot-dip galvanizing method such as a continuous hot-dip galvanizing method and a continuous hot-dip aluminum plating method is mainly used.

In the continuous hot-dip metal plating method, as shown in FIG. 1, a steel strip 1 whose mechanical properties have been adjusted in a continuous furnace and whose surface has been cleaned and activated is supplied to a hot-dip metal plating tank 3 through a snout 2. Sink roll 4 immersed in bath
The traveling direction is changed by this, and after being pulled up from the molten metal plating tank 3 via the support rolls 5 and 6, the gas is injected from the wiping nozzle 7 to remove the excess plating solution and the amount of plating applied is adjusted. Then, it is cooled to room temperature via the top roll 8.

In the continuous hot-dip metal plating method, a sink roll 4 immersed in a bath of a hot-dip metal plating tank 3
The molten metal plating bath immersion members such as the support rolls 5 and 6 are in direct contact with the molten metal, and are in contact with the high-temperature plated steel strip 1 to which the molten metal is attached. For this reason, it is required that the following required characteristics are satisfied as properties required for the hot-dip metal plating bath immersion member.

[0005] Erosion hardly occurs due to molten metal. Low wear due to contact with plated steel strip. The dross component, which is an Fe-Zn alloy floating in the bath, is unlikely to adhere and form as an alloy layer on the member surface. Excellent roll maintainability such as easy roll maintenance for peeling and removing the once adhered molten metal or alloy layer. A long service life as a plating bath immersion member, low cost, and good resistance to thermal shock when immersed in high-temperature molten metal.

[0006] As a plating bath immersion member that can meet such a requirement, there is a plating bath immersed in the surface specified by JIS H8303 (1976).
A roll sprayed with a base self-fluxing alloy, containing one or more of WC or CrC and TiC of 10% or more disclosed in Japanese Patent Publication No. 58-37386, with the balance being a hot corrosion resistant metal, its oxide or A member having a surface coating layer of 0.1 to 2.4 mm thick consisting of two or more of these and unavoidable impurities, ZrO ₂ : 20 to 60
A member provided with a ceramic coating layer consisting of weight% and the balance Al ₂ O ₃ , a member having a cermet coating layer on the surface as disclosed in Japanese Patent Publication No. 55502/1990, wherein the coating layer is made of Co: 5 to A WC-Co based cermet material containing 28%, which is a sprayed coating layer having a porosity of 1.8% or less, or a ceramic sprayed coating mainly containing an oxide or carbide disclosed in Japanese Utility Model Laid-Open No. 63565/1991. Many proposals have been made, such as a roll in which a chemically densified film is formed on the surface of a formed steel roll.

[0007]

However, such a roll sprayed with a Co-based self-fluxing alloy and a method disclosed in Japanese Patent Publication No.
The member disclosed in Japanese Patent No. 819 has a longer life as a plating bath immersion member than the previous untreated surface roll, but when used for about two weeks, some of the coating components in the thermal spray coating melt. Reacts with the plating metal to form an alloy layer on the member surface, or the molten metal penetrates into fine gaps and pores existing in the film, whereby the film on the member surface is locally peeled off, exposing the member base material. Then, it reacts with the molten metal to form an alloy layer, and as a result, the life of the roll is shortened.

Further, even in a sound film portion, a dross component, which is an Fe—Zn alloy floating in a plating bath, locally adheres and grows on the surface to form an alloy layer locally.
The plating properties of the surrounding healthy part and the plated steel strip are different, and an uneven pattern is formed on the plated steel strip and indentation flaws are generated by adhesion products, so that the surface quality of the plated steel sheet is significantly reduced.

Further, the member disclosed in Japanese Patent Publication No. 58-37386 is excellent in corrosion resistance to plating metal because it uses carbide such as WC, CrC, TiC, etc. It has poor mechanical strength such as properties, and it is essential to add a coexisting metal component. However, depending on the type of the added metal, erosion may occur due to a metallurgical / diffusion reaction with the plated metal.

[0010] Metal oxides and metal carbides have corrosion resistance to hot-dip coated metals as physical properties. However, in order to form a coating layer such as a sprayed coating for the purpose of protecting the surface of a member and put it to practical use, the coating layer itself must be used. It is necessary to have hot-dip galvanizing property, and at the same time, to have an environmental barrier property against hot-dip galvanized metal and to protect members from hot-dip galvanized metal.

However, the molten metal immersion member in the prior art contains a metal in the coating component or has pores sufficient for the hot-dip plating metal to penetrate into the coating. Even if it is excellent in hot-dip metal properties, the fact is that it is not in a state where its function can be fully exhibited.

Further, in the member disclosed in Japanese Patent Publication No. 55555/1990 which is excellent in hot-dip galvanized metal properties, there is a local adhesion of a small dross component, which is transferred to a plated steel strip, for example, for an automobile exterior. It is not sufficient for the use of plated steel sheets that require a high degree of surface uniformity as used in applications.

Further, the member disclosed in Japanese Utility Model Laid-Open No. 3-63565 is disclosed in Japanese Patent Publication No. 58-37386 by forming a chemical densification coating on a thermal spray coating on the surface of the member.
Although the adhesion of the alloy layer is improved as compared with the member disclosed in Japanese Patent Publication No. 55502/1990, in a Zn plating bath having a low aluminum content, slight adhesion of the alloy layer occurs, and the problem cannot be completely solved. Is the reality.

Here, an object of the present invention is to provide a method for immersion in a hot-dip galvanizing bath, particularly in a hot-dip galvanizing bath.
Regardless of the plating bath composition, an alloy layer on the member surface,
An object of the present invention is to provide a molten metal plating bath immersion member which can suppress the adhesion of foreign matters and has excellent thermal shock resistance such as film peeling, and a method for producing the same.

Another object of the present invention is that even if a slight alloy layer and foreign matter are attached, it is very easy to remove the attached foreign matter, and it is excellent in pickling resistance and roll maintainability. It is another object of the present invention to provide a plating bath immersion member capable of reducing the cost by extending the life and a method of manufacturing the same.

[0016]

Means for Solving the Problems The present inventors have conducted intensive studies and studies to achieve the above object. As a result, they have found that as a means of achieving these objects, the surface coating by the combination of the cermet film and the stabilized zirconia-based hard ceramic film exhibits particularly excellent characteristics, and completed the present invention.

According to the present invention, (i) the surface of a hot-dip metal plating bath immersion member such as a steel roll is coated with Co by using a spraying means such as a high-speed gas flame spraying method or a plasma spraying method. , Ni and one or more of its alloys in 5-30
Wt% wherein the balance carbide (e.g., WC, chromium carbide such as _{Cr 3 C 2, TiC, ZrC} , NbC, VC, TaC, Mo 2 C, SiC,
(Ii) spraying a cermet coating comprising one or more of HfC as a first sprayed layer to a thickness of 20 to 200 μm;
On the sprayed coating, 60 to 90% by volume of zirconia powder stabilized by the addition of at least one of yttria, magnesia and calcia by the same spraying method,
30 to 60% by weight of zirconia, 0 to 30% by weight of titania, the balance being alumina, and preferably, a titania / alumina weight ratio of 0.75 or less. Forming a second sprayed layer of a ceramic coating having a thickness of 20 to 200 μm; (iii) firing B ₂ O ₃ to seal pores and cracks present on the surface of the upper ceramic coating which is the second sprayed layer. , P ₂ O ₅ , or Si
The second sprayed layer is impregnated with a sealing liquid containing at least one substance capable of forming a glass of O ₂ , and then fired to obtain B ₂ O ₃ ,
A sealing treatment for forming a glass made of at least one oxide of P ₂ O ₅ and SiO ₂ is performed.

In this sealing treatment, the second sprayed layer is impregnated with a water-based or alcohol-based sealing solution such as an aqueous solution of boric acid or phosphoric acid, water glass, silica sol, or an alcohol solution of an alkyl silicate by applying and spraying. After letting 2
It can be carried out by firing at a temperature of 00 to 550 ° C. If necessary, the sealing process may be repeated multiple times.

[0019]

FIG. 2 is a schematic illustration of the surface coating structure of the hot-dip metal plating bath immersion member of the present invention. Immersion member that is the mother ground
Ten examples are steel rolls such as sink rolls and support rolls, or roll drive or support members such as bearings. The material of the immersion member 10 preferably has a coefficient of thermal expansion as close as possible to that of the first sprayed layer. For example, SUS403 (martensitic stainless steel).
Before the immersion member is coated by spraying according to the present invention,
Preferably, the surface is roughened by conventional means such as shot blasting.

The surface of the base immersion member 10 is provided with a first sprayed layer.
A cermet film having a thickness of 20 to 200 μm, preferably 50 to 150 μm, which is 12, is provided. The thickness of the first sprayed layer is 20μ
If it is less than 200 m, the object cannot be achieved. On the other hand, if it is more than 200 m, the peeling may occur. Preferably 50-15
0 μm.

On this first sprayed layer, a second sprayed layer 14, a ceramic coating having a thickness of 20 to 200 μm, preferably 50 to 150 μm, is provided. The second sprayed layer is also 20μm thick
If it is less than 200 μm, there is a possibility that problems such as peeling may occur. The surface of the ceramic coating has been subjected to a sealing treatment, which is shown as a sealing treatment layer 16 for convenience.

As the thermal spraying method, any method such as plasma spraying, high-speed gas flame spraying, explosive spraying, and arc spraying may be employed. The cermet coating of the first sprayed layer is composed of 5 to 30% by weight, preferably 10 to 20% by weight of one or more metal components selected from Co, Ni and alloys thereof (eg, Ni-Cr alloy).
% By weight, with the balance being carbide, preferably WC, Cr ₃ C ₂ , Ti
One or two of C, ZrC, NbC, VC, TaC, Mo ₂ C, SiC, HfC
Consists of more than species. If the metal component is out of the above range, if it is less than 5% by weight, it is easy to peel off, and if it exceeds 30% by weight, the corrosion resistance to the plated metal is deteriorated. Carbide is compounded for corrosion resistance to plated metal.
WC is preferred.

The ceramic coating of the second thermal spraying layer may comprise at least one of yttria, magnesia and calcia, preferably 60 to 90% by volume, preferably 70 to 80% by volume of zirconia powder stabilized by the addition of yttria; 30 ~
Hard ceramic powder comprising 60% by weight, preferably 40 to 50% by weight of zirconia and optionally up to 30% by weight, preferably up to 20% by weight of titania, the balance being alumina
It is formed by spraying a mixed powder of 10 to 40% by volume, preferably 20 to 30% by volume. That is, the composition of the mixed powder used for the thermal spraying of the second thermal spray layer is as follows. The ratio in parentheses is a preferable ratio.

I. Stabilized zirconia powder 60-90% by volume (70-80% by volume) II. Hard ceramic powder consisting of 10-40% by volume
(20 to 30% by volume) Zirconia 30 to 60% by weight (40 to 50% by weight) Titania 0 to 30% by weight (0 to 20% by weight) Residual alumina Yttria, magnesia and / or stabilizing element to zirconia powder The amount of calcia to be added is not particularly limited as long as it is normally added, and for example, a total of about 5 to 20% by weight based on the total amount of zirconia is sufficient.

If the zirconia in the hard ceramic powder exceeds 60% by weight, the hardness becomes insufficient, and if it is less than 30% by weight, the zirconia may be easily peeled. On the other hand, if the content of titania added as desired exceeds 30%, peeling becomes easy. Preferably 40 to 50% by weight of zirconia and 0 of titania
~ 20% by weight.

In addition, the mixing amount of the hard ceramic powder in the starting mixed powder of the second sprayed layer is out of the range of 10 to 40% by volume (therefore, the amount of zirconia powder containing the stabilizing element is 60%).
If it is out of the range of 90% by volume), the intended effect cannot be sufficiently exhibited.

In the present invention, the cermet-based coating is used for the first sprayed layer because the ceramic coating of the second sprayed layer has a relatively large number of pores in the coating by the current spraying technique and sometimes has a penetration defect. Film defects, peeling,
While there is a possibility of causing troubles such as adhesion of the alloy layer, in the case of the cermet coating, even with the current thermal spraying technology, a dense coating with relatively few pores and the like can already be obtained, which causes a trouble. Protect the roll base material at the time.

Further, the use of a ceramic coating for the second sprayed layer is because ceramic has low wettability with molten metal and does not exhibit reactivity with molten metal or dross components.
This is because it is excellent in suppressing foreign matter adhesion such as an alloy layer. In particular, the zirconia-based ceramic sprayed coating of the present invention is excellent in low wettability, erosion resistance, abrasion resistance, thermal shock resistance, and foreign matter adhesion resistance with a hot-dip metal as a hot-dip metal bath immersion member.

The reason why the surface of the second sprayed layer is subjected to the sealing treatment is that, as described above, the ceramic sprayed coating has an advantage that the wettability with the hot-dip metal is inferior. Micropores and cracks are liable to occur in the thermal spray coating, and there is a problem that the hot-dip plating metal penetrates into this portion and the coating is destroyed. Therefore, this problem is solved by sealing.

In the sealing treatment, a sealing liquid containing at least one compound (sealing agent) serving as a supply source of B ₂ O ₃ , P ₂ O ₅ , or SiO ₂ is applied to the ceramic coating of the second sprayed layer. Impregnated into
The sealing liquid is permeated into pores and cracks opened on the surface of the ceramic film, and then fired to vitrify the sealing agent through dehydration, condensation, polymerization and / or melting. Therefore, at least one oxide-based vitreous sealing layer of B ₂ O ₃ , P ₂ O ₅ , and SiO ₂ is formed after the sealing treatment. These vitreous sealing layers are characterized by having acid resistance and relatively low wettability with the plating metal.

The volume ratio of the glass present in the ceramic coating (that is, in the pores and cracks) is appropriately determined by the porosity of the coating. In the case of the present invention, preferably, the vitreous content in the ceramic coating is 0.5 to 5
% By volume. Although the thickness of the vitreous sealing layer is not particularly limited, it is usually very thin, 0.5 to 10 μm.

Examples of the sealing agent used in the present invention are not particularly limited as long as they can form SiO ₂ , P ₂ O ₅ , or B ₂ O ₃ based glass by firing. The sealing agent is used as a sealing solution in the form of a solution or a colloid solution (sol) so that fine pores and cracks on the surface of the ceramic film can be easily penetrated. Examples of sealants that can be used include:
Examples thereof include a silica-based sol (silica sol), an aqueous solution of boric acid, an aqueous solution of phosphoric acid, water glass, and an alcohol solution of an alkyl silicate or a partial hydrolyzate thereof.

When a phosphoric acid aqueous solution or boric acid aqueous solution is impregnated in pores and cracks and heated, water as a solvent evaporates, and phosphoric acid or boric acid solid remains in pores and the like. When the temperature is further increased, the glass is vitrified to produce a glass composed of P ₂ O ₅ or B ₂ O ₃ . This glass is stably present even in pores and cracks in the thermal spray coating under the conditions of use as a member immersed in a molten metal plating bath. On the other hand, examples of the sealing liquid containing a supply source of SiO ₂ include silica sol, water glass, an alkyl silicate or an alcohol solution of a partial hydrolyzate thereof.

The silica sol is obtained by dispersing colloidal particles of silica (SiO ₂ ) in water or an alcoholic dispersion medium, and the colloidal particles are extremely small (0.005 to 0.3 μm).
m), it can penetrate into pores and cracks of several μm on the surface of the thermal sprayed coating together with the liquid. Then, when the liquid is vaporized and evaporated by baking, the aggregates of the colloidal particles remain and vitrify, and the vitrified SiO ₂ closes the pores and cracks.

Water glass is obtained by dissolving an alkali silicate obtained by melting silicon dioxide and an alkali in water.
It is mainly sodium silicate using Na ₂ O for alkali. After being impregnated into the pores and cracks and then heated to remove water, fire-resistant and glassy Na ₂ O.n-SiO ₂ remains.

As the alkyl silicate, tetraalkoxysilane represented by the following general formula (1) and general formula (1)
Trialkoxysilane represented by (2) can be exemplified,
It is not limited to these. These alkyl silicates can also be used in the state of their partial hydrolysates.

Si (OR ¹ ) ₄ ... (1) R ² Si (OR ³ ) ₃ ... (2) where R ^{1 is} an alkyl group having 1 to 4 carbon atoms R ² : Hydrocarbon group having 1 to 6 carbon atoms R ³ : alkyl group having 1 to 4 carbon atoms One or more alkyl silicates can be used. Preferred alkyl silicates are tetraalkoxysilanes or partial hydrolysates thereof, co-partial hydrolysates of tetraalkoxysilanes and trialkoxysilanes, and partial hydrolysates of tetraalkoxysilanes and partial hydrolysates of trialkoxysilanes. It is a mixture. The alkyl silicate or its partial hydrolyzate can be used in the form of an alcohol (eg, ethanol) solution. This solution contains water or a hydrolysis catalyst (eg,
(Acids such as hydrochloric acid) may be added in small amounts.

After the alkyl silicate is impregnated into the pores and cracks on the surface of the second sprayed layer and then heated to remove water and alcohol generated by hydrolysis, a gel composed of siloxane bonds is formed. When vitrification is performed, dense sealing treatment with SiO ₂ glass can be performed.

The sealing liquid is not limited to the above-mentioned ones, and any other solution or sol may be used if the acid-resistant oxide seals pores and cracks after impregnation and heat curing. Should be fine. Further, in order to sufficiently impregnate the fine pores and cracks on the surface of the thermal spray coating with the sealing liquid, if necessary, a solvent such as water or alcohol can be added to adjust the viscosity and the surface tension.

As means for impregnating the pores and cracks on the surface of the second sprayed coating with the sealing liquid, immersion in a brush, application by spraying, brush coating, and the like can be considered. The member may be evacuated prior to impregnation to promote impregnation. After the impregnation with the sealing liquid, the solvent (water, alcohol, etc.) of the sealing agent remaining in the pores and cracks is evaporated, and the sealing agent is decomposed and vitrified as necessary. After drying,
Drying and baking are performed by heating. At this time, it should be noted that it is desirable to increase the temperature relatively slowly in order to avoid rapid evaporation of the solvent. The heating temperature varies depending on the type of sealing agent and its solvent, but is 200 to 550 ° C.
0.5 to several hours.

In the present invention, the sprayed coating structure is formed in two layers, and the first sprayed layer is provided with a cermet coating which is relatively resistant to formation of pores and cracks and has excellent corrosion resistance. In the event that the roll base material is destroyed, care was taken not to erode the roll base material.

The second sprayed layer is provided with an oxide ceramic film having low wettability with the hot-dip metal, excellent thermal shock resistance, and excellent environmental barrier properties against the hot-dip metal, thereby providing a plating bath immersion member. When used, the member protects the member from the hot-dip plating bath and functions so as to have excellent foreign matter adhesion preventing properties.

Further, a sealing layer is provided on the surface of the upper thermal spray coating to close pores and cracks present in the thermal spray coating. As a sealant at that time, by selecting a material that can form a glass that has low wettability with plating metal as well as ceramic sprayed coating and also has acid resistance, it improves foreign matter adhesion resistance in hot-dip metal bath In addition, it is possible to provide the immersion member after pulling up from the plating bath with excellent maintainability (adhered metal can be easily removed by pickling).

As a result, as a plating bath immersion member in the molten metal plating bath, foreign substances such as an alloy layer can be prevented from adhering. Therefore, it is possible to completely prevent surface defects of the plated steel strip caused by the plating bath immersion member. become. further,
Regarding the maintenance of the plating bath immersion member after being lifted from the plating bath, the adhered metal can be completely removed by an extremely easy means of pickling, which also has the advantage that the life can be extended and the holding quantity can be reduced. .

[0045]

Embodiments of the present invention will be described below. Percentages are by weight unless otherwise specified. The sink roll 4 and the support roll 5 of the continuous galvanizing line shown in FIG.
With regard to No. 6, after the surface of the roll was roughened using a shot blast, a cermet film containing a WC-based carbide in the first sprayed layer was formed using a high-speed gas flame spraying method [WC-20]
% (Ni-50% Cr)] was sprayed to a thickness of about 50 μm. Next, a zirconia ceramic coating [75 vol% (ZrO ₂ +8
% Y ₂ O ₃ ) +25 vol% (ZrO ₂ + 55% Al ₂ O ₃ )] was sprayed to a thickness of about 100 μm using a plasma spraying method. Roll base material is SUS
403.

Further, as a sealing treatment of the ceramic coating of the second sprayed layer, a sealing liquid containing one or more of the supply sources of SiO ₂ , P ₂ O ₅ and B ₂ O ₃ is applied, and 500 μm is applied. It was baked at a temperature of 1 ° C. for 1 hour to perform a heat curing treatment of the applied sealing agent. The source of SiO ₂ was tetraethoxysilane (= ethyl silicate), and the ethanol solution was used as the sealing liquid. The sources of P ₂ O ₅ and B ₂ O ₃ were aqueous phosphoric acid and boric acid, respectively.

An immersion test was conducted in which the rolls having been subjected to the above-mentioned surface treatment were used for a total of one month in a plating bath of a continuous galvanizing line. As the test conditions, for example,
Hot-dip plating conditions were set so as to be compatible with the WC-12% Co sprayed coating.

Table 1 shows the results. In the comparative material and the conventional WC-12% Co thermal spraying roll, despite the adhesion and wrapping of the alloy layer, there was no adhesion of the foreign matter such as the alloy layer in the material of the present invention.

Further, after lifting from the hot-dip galvanizing bath, the zinc adhered to the roll surface was removed by pickling, and the film was observed. However, no decrease in the film peeling or film abrasion was observed for the material of the present invention. In addition to maintaining a sound coating even after long-term use, it has been found that it has sufficient pickling resistance even in roll maintenance methods such as pickling, which were not conventionally performed on thermal spray rolls. did. This means that the maintenance accuracy of the plating bath immersion members, including the roll bearings, can be easily improved. The immersion member can always be managed in a healthy state. Next, the coating composition in the present invention was changed as shown in Table 2, and the same immersion test as described above was performed for each. The results are also shown in Table 2.

[0050]

[Table 1]

[0051]

[Table 2]

Second layer: Material A = [ZrO ₂ + 7% CaO] 75 vol% + [Z
rO ₂ + 55% Al ₂ O ₃ ] 25vol% B material = [ZrO ₂ + 8% MgO] 75vol% + [ZrO ₂ + 20% TiO ₂ + 35% Al
₂ O ₃ ] 25vol% ◎: No alloy layer adhered

[0053]

As described above, the molten metal plating bath immersion member subjected to the thermal spray coating and the sealing treatment of the present invention can prevent foreign matter such as an alloy layer from adhering to the surface of the immersion member. It is possible to manufacture a high-quality plated steel sheet as described above.

Further, since the surface of the immersion member can be maintained in a clean state, the occurrence of degrading of the steel sheet due to the adhesion of foreign substances can be prevented, the yield can be improved, and the thermal shock resistance such as film peeling is excellent. Long life can be achieved.

Furthermore, since it is excellent in preventing foreign matter from adhering to an alloy layer and the like, and is also excellent in acid resistance, it is extremely easy to maintain the member after being pulled up from the plating bath, and the number of spare members to be kept can be minimized. It also has benefits.
Further, since adhesion of foreign matter such as an alloy layer in the molten metal plating bath can be prevented, it is possible to achieve a chance-free schedule.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of a continuous hot-dip metal plating line.

FIG. 2 is an explanatory diagram of a surface film structure of a member immersed in a molten metal plating bath according to the present invention.

[Explanation of symbols]

1: Steel strip 2: Snout 3: Hot-dip plating metal tank 4: Sink roll 5, 6: Support roll 7: Wiping nozzle 8: Top roll 10: Member 12: First sprayed layer 14: Second sprayed layer 16: Sealing Layer 18: Pores

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-174440 (JP, A) JP-A-1-225761 (JP, A) JP-A-3-94048 (JP, A) JP-A-4- 88159 (JP, A) JP-A-5-171402 (JP, A) JP-A-6-81115 (JP, A) JP-A-7-173592 (JP, A) (58) Fields investigated (Int. ⁶ , DB name) C23C 2/00-6/00 C23C 28/00-28/04

Claims (4)

(57) [Claims] 1. A member immersed in a hot-dip metal plating bath, comprising: (i) 5 to 30% by weight of one or more of Co, Ni and an alloy thereof provided on its surface, with the balance being WC, Cr ₃ C ₂ , T
A first sprayed layer having a thickness of 20 to 200 μm, which is a cermet coating made of one or more carbides selected from the group consisting of iC, ZrC, NbC, VC, TaC, Mo ₂ C, SiC, and HfC. (Ii) 60-90% by volume of zirconia powder stabilized by addition of at least one of yttria, magnesia and calcia, and 30-60% by weight of zirconia provided as an upper layer of the first sprayed layer, and the balance being the balance A second sprayed layer having a thickness of 20 to 200 μm, which is obtained by spraying a mixed powder of 10 to 40% by volume of a hard ceramic powder made of alumina; and (iii) a surface of the second sprayed layer. A vitreous sealing layer made of at least one oxide of B ₂ O ₃ , P ₂ O ₅ , and SiO ₂ , for immersion in a hot-dip metal plating bath. 2. A member immersed in a molten metal plating bath, comprising: (i) 5 to 30% by weight of one or more of Co, Ni and an alloy thereof provided on the surface thereof, with the balance being WC, Cr ₃ C ₂ , T
A first sprayed layer having a thickness of 20 to 200 μm, which is a cermet coating made of one or more carbides selected from the group consisting of iC, ZrC, NbC, VC, TaC, Mo ₂ C, SiC, and HfC. And (ii) zirconia powder 60-90 volume% stabilized by the addition of at least one of yttria, magnesia and calcia, 30-60 weight% zirconia, titania provided as an upper layer of the first sprayed layer A ceramic coating obtained by spraying a mixed powder of 30% by weight or less and 10 to 40% by volume of a hard ceramic powder composed of a balance of alumina and having a thickness of 20 to
(Iii) a second thermal spray layer having a thickness of 200 μm; and (iii) a vitreous sealing layer for sealing the surface of the second thermal spray layer and comprising at least one oxide of B ₂ O ₃ , P ₂ O ₅ , and SiO _2. And a member immersed in a hot-dip metal plating bath. 3. (i) Applying one or more of Co, Ni and its alloys to the surface of a hot metal plating bath immersion member for 5 to 5 minutes.
30% by weight, with the balance being WC, Cr ₃ C ₂ , TiC, ZrC, NbC, VC,
A powder comprising one or more carbides selected from the group consisting of TaC, Mo ₂ C, SiC and HfC is sprayed to form a first powder.
Forming a cermet coating having a thickness of 20 to 200 μm as a sprayed layer; and (ii) forming a zirconia powder 60- stabilized on the upper layer of the first sprayed layer by adding at least one of yttria, magnesia and calcia. 90% by volume, 30 to 60% by weight of zirconia, balance of alumina 10 to 10% of hard ceramic powder
Spraying the mixed powder with 40% by volume to form a ceramic coating having a thickness of 20 to 200 μm as a second spraying layer; and (iii) firing the B _{2 on} the surface of the ceramic coating of the second spraying layer by firing. Impregnated with a sealing solution containing at least one substance that forms O ₃ , P ₂ O ₅ or SiO ₂ , and calcined at a temperature of 200 to 550 ° C. to obtain B ₂ O ₃ , P ₂ O ₅ and SiO ₂ Performing a sealing treatment for forming a glass made of at least one kind of oxide once or a plurality of times. 4. (i) Applying one or more of Co, Ni and its alloys to the surface of a hot metal plating bath immersion member for 5 to 5 minutes.
30% by weight, with the balance being WC, Cr ₃ C ₂ , TiC, ZrC, NbC, VC,
A powder comprising one or more carbides selected from the group consisting of TaC, Mo ₂ C, SiC and HfC is sprayed to form a first powder.
Forming a cermet coating having a thickness of 20 to 200 μm as a sprayed layer; and (ii) forming a zirconia powder 60- stabilized on the upper layer of the first sprayed layer by adding at least one of yttria, magnesia and calcia. A mixed powder of 90% by volume, 30 to 60% by weight of zirconia, 30% by weight or less of titania, and 10 to 40% by volume of a hard ceramic powder composed of alumina is used as a second sprayed layer having a thickness of 20 to 200%. forming a ceramic coating having a thickness of at least one substance which forms B ₂ O ₃ , P ₂ O ₅ or SiO ₂ by firing on the surface of the ceramic coating of the second sprayed layer; One or more sealing treatments for impregnating the pore liquid and firing at a temperature of 200 to 550 ° C. to form a glass comprising at least one oxide of B ₂ O ₃ , P ₂ O ₅ and SiO ₂ Performing a molten metal plating process. Manufacturing method of the immersion member for use.