CN111315919A

CN111315919A - Member for in-bath facility, molten metal in-bath facility, and hot-dip plated metal material production device

Info

Publication number: CN111315919A
Application number: CN201880071929.XA
Authority: CN
Inventors: 水野显; 栗栖泰; 辰巳佳宏; 松井祥司
Original assignee: Nippon Steel and Sumitomo Metal Corp
Current assignee: Nippon Steel Corp
Priority date: 2018-02-27
Filing date: 2018-02-27
Publication date: 2020-06-19
Anticipated expiration: 2038-02-27
Also published as: WO2019167149A1; CN111315919B

Abstract

The invention aims to further improve the corrosion resistance of the equipment member in the bath. The member for in-bath facilities according to the present invention is a member for in-bath facilities used for molten metal in a hot-dip metal material production apparatus, and has a coating layer containing hard particles and a matrix, the matrix containing, in mass%, C: 0.5% -3%, Cr: 15% -30%, W: 7% -21%, Si: 0-4%, B: 0% -4% and Ni: 0% to 30% of a cobalt-based alloy containing Co and impurities in the balance, a metal part, and particulate carbides containing at least one precipitated W or Cr, and the hard particles include one or both of a monomer of at least one selected from the group consisting of tungsten carbide, ditungsten carbide, chromium carbide, titanium carbide, and niobium carbide, and/or a granulated substance obtained by granulating a monomer with a binder.

Description

Member for in-bath facility, molten metal in-bath facility, and hot-dip plated metal material production device

Technical Field

The present invention relates to a member for in-bath facility, molten metal in-bath facility, and hot-dip plated metal material production apparatus.

Background

When plating the surface of a metal material such as a steel sheet with a metal such as zinc, a manufacturing method is often employed in which the metal material is continuously transferred in a tensioned state in a bath in which the metal used for plating is melted. In this case, the following steps are often employed: the metal material is charged into the molten metal bath from the furnace nose, and is pulled up from the bath by the backup rolls while being conveyed in the bath along the periphery of the sink rolls.

Such a sink roll, a shaft supporting the roll, and a bearing are often exposed to molten metal and slide, and therefore, are gradually worn out. Therefore, excellent wear resistance is required for members for equipment in a bath, such as a sink roll, a shaft of a back-up roll, a bearing, and the like. Accordingly, various techniques have been developed to improve the wear resistance of the members for facilities in the bath.

For example, patent document 1 below discloses a technique for forming a coating layer containing a cobalt (Co) -based alloy and at least one selected from tungsten carbide, chromium carbide, titanium carbide, and niobium carbide on the surface of a metal material by hot isostatic pressing.

Further, patent document 2 below discloses a tungsten carbide composite lining material for centrifugal casting, which has reduced attack (opennent attack) properties by using spherical hard tungsten carbide particles having a specific particle diameter and adopting a lining method using a centrifugal casting method.

Further, patent document 3 below discloses a corrosion-resistant and wear-resistant sliding member in which a Ni-based self-fluxing alloy is used as a matrix of tungsten carbide, and the member is covered by hot isostatic pressing, thereby improving corrosion resistance and wear resistance.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 7-268648

Patent document 2: japanese laid-open patent publication No. 7-290186

Patent document 3: japanese patent laid-open publication No. 2000-266055

Disclosure of Invention

Problems to be solved by the invention

However, the centrifugal casting method described in patent document 2 still has room for improvement in the characteristics of the produced member.

Further, the hot isostatic pressing materials used in

patent documents

1 and 3 have a dense and homogeneous structure, and therefore exhibit excellent wear resistance to members obtained by the thermal spraying method or the build-up welding method, while the addition amount of hard particles such as various carbides is limited because they cause generation of voids. Therefore, as the continuous use period for the purpose of improving productivity increases, the problem that the abrasion amount and the frictional force increase rapidly due to the falling off and protrusion of the hard particles caused by the melting loss of the matrix becomes obvious.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a member for in-bath facilities capable of further improving corrosion resistance, and molten metal in-bath facilities and a hot-dip plated metal material production apparatus provided with the member for in-bath facilities.

Means for solving the problems

The gist of the present invention is as follows.

(1) A member for in-bath facilities used for molten metal in-bath facilities in a hot-dip metal material production apparatus,

the member for in-bath equipment has a coating layer provided on at least a part of the surface of the member for in-bath equipment,

the coating layer comprises hard particles and a matrix for holding the hard particles,

the matrix contains, in mass%, C: 0.5% -3%, Cr: 15% -30%, W: 7% -21%, Si: 0-4%, B: 0% -4% and Ni: 0% to 30%, the balance comprising Co and impurities, and comprising a metal part and a particulate carbide containing at least one of precipitated W or Cr,

the hard particles include one or both of a monomer (simple substance) of at least one selected from the group consisting of tungsten carbide, ditungsten carbide, chromium carbide, titanium carbide and niobium carbide, and a granulated substance obtained by granulating the monomer using a binder.

(2) The member for an in-bath facility according to (1), wherein the base contains, in mass%, C: 1 to 2 percent.

(3) The member for in-bath equipment according to (1) or (2), wherein the base contains, in mass%, a material selected from the group consisting of

Si：0.5％～4％、

B: 0.5% -4%, and

ni: 5% to 30% of at least one of the group.

(4) The member for in-bath equipment according to any one of (1) to (3), wherein a content of W in the matrix is 21% by mass or less and a content of Ni is 5% by mass or more.

(5) The member for in-bath facilities according to any one of (1) to (4), wherein the carbide precipitated in the matrix is a carbide containing a carbide selected from the group consisting of Co and Co₃W₃C、Co₆W₆C、WC、W₂C、Cr₂₃C₆、Cr₇C₃And Cr₃C₂One or more carbides of the group consisting of.

(6) The member for in-bath equipment according to any one of (1) to (5), wherein a content of carbide precipitated in the matrix is 5% by volume to 80% by volume based on an entire volume of the coating layer.

(7) The member for in-bath equipment according to any one of (1) to (6), wherein the hard particles have a particle diameter of 0.001mm to 1 mm.

(8) The member for in-bath equipment according to any one of (1) to (7), wherein the hard particles have a particle diameter of 0.02mm to 0.5 mm.

(9) The member for in-bath equipment according to any one of (1) to (8), wherein a content of the hard particles is 15 to 70 vol% based on an entire volume of the coating layer.

(10) The member for an in-bath facility according to item (9), wherein a content of the hard particles is 25 to 55 vol% based on an entire volume of the coating layer.

(11) The member for in-bath facility according to any one of (1) to (10), wherein the thickness of the coating layer is 1mm to (the thickness dimension of the member for in-bath facility) -7 mm.

(12) The member for an in-bath facility according to any one of (1) to (11), which is a roller member of the in-bath facility.

(13) The member for an in-bath facility according to any one of (1) to (12), which is a roll support shaft or a roll bearing of the in-bath facility.

(14) A molten metal in-bath facility comprising the member for an in-bath facility according to any one of (1) to (13).

(15) A hot-dip plated metal material production apparatus comprising the member for in-bath equipment according to any one of (1) to (13).

Effects of the invention

As described above, according to the present invention, the amount of carbon contained in the cobalt-based alloy is set to a predetermined range, and granular carbides of W or Cr are precipitated in the cobalt-based alloy, whereby the corrosion resistance of the member for equipment in a bath can be further improved.

Drawings

Fig. 1 is an explanatory view schematically showing the configuration of a hot-dip plated metal material production apparatus according to an embodiment of the present invention.

Fig. 2 is a partial sectional view schematically showing the structure of a member for an in-bath facility according to an embodiment of the present invention.

Fig. 3 is an explanatory view showing an example of a cross-sectional captured image of a cover layer provided in the in-bath device member shown in fig. 2.

Fig. 4 is an explanatory diagram schematically showing an example of the HIP device.

Fig. 5 is an explanatory diagram schematically showing an example of the HIP device.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, the same reference numerals are used for the components having substantially the same functional configuration, and redundant description is omitted.

Hereinafter, a member for in-bath facilities, a molten metal in-bath facility, and a hot-dip plated metal material production apparatus according to an embodiment of the present invention will be described in detail. The member for in-bath facilities of the present embodiment is used for molten metal in-bath facilities in a hot-dip metal material production apparatus.

In addition, as an example of the hot-dip galvanized metal material, the following description focuses on a hot-dip galvanized steel sheet, and exemplifies facilities in a molten zinc bath in a continuous hot-dip galvanized material production apparatus. However, the member for in-bath facilities of the present invention is not limited to the member for in-bath facilities disposed in the molten zinc bath. That is, the member for in-bath facility according to the present invention can be used for a molten metal in-bath facility disposed in an arbitrary molten metal bath. The member for in-bath facility according to the present invention is applicable not only to a continuous hot-dip metal material producing apparatus but also to a molten metal in-bath facility of a batch type hot-dip metal material producing apparatus.

<1. Hot-dip Metal plate production apparatus >

Before the description of the in-bath facility member according to the present embodiment, the entire configuration of the hot-dip plated metal material manufacturing apparatus according to the present embodiment using the in-bath facility member will be briefly described with reference to fig. 1, taking a continuous hot-dip galvanized steel sheet manufacturing apparatus as an example. Fig. 1 is an explanatory view schematically showing the configuration of a hot-dip plated metal material production apparatus according to an embodiment of the present invention.

As schematically shown in fig. 1, the apparatus for manufacturing a continuously hot-dip galvanized steel sheet mainly includes a molten zinc bath 1, a furnace nose 2, a sink roll 3, and a pair of backup rolls 4.

In the molten zinc bath 1, zinc as the molten metal M for plating the surface of the passing steel sheet S is held in a molten state. The snout 2 is a device for continuously charging the steel sheet S into the molten zinc bath 1, and is filled with an inert gas such as nitrogen. The sink roll 3 and the backup roll 4 have support shafts 5 and 6, respectively, and the support shaft 6 is connected to a driving source (not shown) such as a motor and is rotationally driven at a constant speed in the direction of the arrow in the figure.

In addition, the apparatus for manufacturing a continuously hot-dip galvanized steel sheet as shown in fig. 1 is further provided with various devices (not shown) such as an ingot loading device, a dross collecting device, and a roll stand, as necessary.

The members for in-bath facilities of the present embodiment are used as members for in-bath facilities disposed in the molten zinc bath 1, such as the sink roll 3, the support shafts 5 and 6 for supporting the rolls 4, and bearings (not shown).

<2. Member for in-bath Equipment >

Next, the members for in-bath facility according to the present embodiment will be described in detail with reference to fig. 2 and 3. Fig. 2 is a partial sectional view schematically showing the structure of the member for in-bath facility according to the present embodiment. Fig. 3 is an explanatory view showing an example of a cross-sectional captured image of a cover layer provided in the in-bath device member shown in fig. 2.

As schematically shown in fig. 2, the in-bath facility member 10 according to the present embodiment includes a base material 11 and a coating layer 13 formed on at least a part of the surface of the base material 11.

The base material 11 is not particularly limited, and is appropriately selected from known steel materials in accordance with the properties such as strength required for the sink roll 3 and the backup roll 4. Examples of such a base material 11 include various stainless steel plates such as SUS 316L.

The coating layer 13 is formed on at least a portion of the base material 11, such as a sliding portion of a shaft or a bearing, which is required to have corrosion resistance and wear resistance as the in-bath facility member 10. The coating layer 13 may be formed on the entire surface of the base material 11. The cover layer 13 is formed on a desired portion of the base material 11 by a known method such as Hot Isostatic Pressing (HIP).

This cap layer 13, as shown in fig. 3, contains (a) a cobalt-based alloy 15 containing cobalt (Co) as a main component and (b) hard particles 17 contained in the cobalt-based alloy 15. Here, the cobalt-based alloy 15 of the present embodiment functions as a matrix for holding the hard particles 17. In the in-bath facility member 10 according to the present embodiment, carbides, which will be described later, are precipitated and dispersed in the cobalt-based alloy 15 as a matrix.

The coating layer 13 described in detail below is preferably formed on the surface of the base material 11 by HIP treatment to a thickness of 1mm to (the thickness of the device member in the bath) 7 mm. In the case where the thickness of the cover layer 13 (thickness d shown in fig. 2) is less than 1mm, there is a possibility that the durability of the cover layer 13 is insufficient and sufficient reliability cannot be obtained depending on other configurations of the cover layer 13. When the thickness of the coating layer 13 exceeds (the thickness of the device member in the bath) 7mm, the base material 11 may be deformed or broken by internal stress generated at the HIP treatment depending on the other structure of the coating layer 13. The thickness of the covering layer 13 is preferably 1.2mm to 7mm, more preferably 1.4mm to 5 mm.

The coating layer 13 will be described in detail below.

[2.1. cobalt-based alloy 15]

The cobalt-based alloy 15 containing Co as a main component functions as a matrix of the hard particles 17. The matrix, i.e., the cobalt-based alloy 15, contains the following components. In the following component expressions,% means a metal-equivalent amount expressed in mass%. The components shown below are values containing precipitates described later.

C：0.5％～3％

Cr：15％～30％

W：7％～21％

Si：0～4％

B：0％～4％

Ni：0％～30％

In addition, in the cobalt-based alloy 15, the remaining part of the above components contains Co and impurities.

C：0.5％～3％

Carbon (C) is an element used to improve the erosion resistance of the coating layer 13. By setting the C content to 0.5% to 3%, the carbide 19 can be precipitated around the vicinity of the hard particles 17, and the erosion resistance of the coating layer 13 can be improved, thereby improving the corrosion resistance. On the other hand, when the C content is less than 0.5%, the amount of carbide precipitation in the cobalt-based alloy 15 is insufficient, and it is difficult to improve the erosion resistance, which is not preferable. When the C content exceeds 3%, the toughness of the coating layer 13 is lowered, and cracking may occur during the HIP treatment, which is not preferable. The amount of C is preferably 0.6% or more, and more preferably 0.7% or more, from the viewpoint of effectively precipitating carbides of W and Cr as described later. From the viewpoint of suppressing the decrease in toughness and more reliably suppressing the embrittlement of the coating layer 13, the C content is preferably 2.2% or less, and more preferably 1.9% or less.

The amount of C contained in the cobalt-based alloy 15 is preferably 1% or more. By setting the C content to 1% or more, as shown in fig. 3, not only in the vicinity of the hard particles 17 but also throughout the cobalt-based alloy 15, the carbide 19 can be precipitated in a uniformly dispersed manner, and the erosion resistance of the coating layer 13 can be further improved, thereby further improving the corrosion resistance. In addition, since the effect of improving the melting loss resistance and corrosion resistance tends to be saturated if the C content exceeds 2%, the upper limit of the C content is preferably 2%.

Cr：15％～30％

Chromium (Cr) is an element used to improve the corrosion resistance of the coating layer 13. By setting the Cr content (Cr equivalent) to 15% or more, the corrosion resistance of the coating layer 13 can be improved, and Cr can be used₂₃C₆、Cr₇C₃、Cr₃C₂Carbide 19 as a main body precipitates. On the other hand, if the Cr content exceeds 30%, the toughness of the coating layer 13 is lowered, and cracking may occur during the HIP treatment, which is not preferable. The amount of Cr is preferably 15% or more, more preferably 18% or more. The Cr content is preferably 30% or less, and more preferably 28% or less.

W：7％～21％

Tungsten (W) is an element used to increase the strength of the coating layer 13. By setting the W content to 7% or more and 21% or less, Co can be efficiently precipitated in the cobalt-based alloy 15₃W₃C、Co₆W₆C、WC、W₂The carbide 19 mainly composed of C improves the wear resistance of the coating layer 13. On the other hand, when the W content is less than 7%, the above-described effect of improving the wear resistance cannot be sufficiently obtained, which is not preferable. When the W content exceeds 21%, the toughness of the coating layer 13 is lowered, and cracking may occur during the HIP treatment, which is not preferable. The W content is preferably 9% or more, more preferably 11% or more. The W content is preferably 19% or less, more preferably 18% or less.

In addition, the matrix may further contain, in addition to the above components, Si: 0.5% to 4% inclusive, B: 0.5% to 4% inclusive, Ni: 5% to 30% or less. Since these elements are optional components, the content of these elements may be, of course, 0% or less of the above lower limit.

Ni：5％～30％

Nickel (Ni) is an element used to improve the toughness of the coating layer 13. By setting the Ni content to 5 mass% or more, the toughness of coating layer 13 can be improved. On the other hand, if the Ni content is less than 5%, the above-described toughness-improving effect may not be sufficiently obtained. When the Ni content exceeds 30%, the corrosion resistance of the coating layer 13 to the molten metal (molten zinc) may be significantly lowered, which is not preferable. The amount of Ni is preferably 5% or more, more preferably 10% or more. The Ni content is preferably 25% or less, and more preferably 22% or less.

In particular, it is preferable to use W and Ni in combination so that the content of W in the matrix is 21% by mass or less and the content of Ni is 5% by mass or more. The coating layer 13 of the embodiment may have a reduced toughness while improving corrosion resistance by the particulate carbide described later. By setting the contents of Ni and W to the above ranges, cracking of coating layer 13 can be more reliably prevented.

Si：0.5％～4％

Silicon (Si) is an element that can reduce the melting point of the cobalt-based alloy 15 to, for example, 1100 ℃. By setting the Si content to 0.5% or more, such a melting point lowering effect can be obtained, and the denseness of the coating layer 13 can be further improved in the HIP treatment. On the other hand, if the Si content exceeds 4%, the toughness of the coating layer 13 is lowered, and cracking may occur during the HIP treatment, which is not preferable. In order to more reliably obtain the melting point lowering effect, the amount of Si is preferably 1% or more, and more preferably 1.5% or more. In order to sufficiently ensure the toughness of the coating layer 13, the Si content is preferably 3.3% or less, and more preferably 3% or less.

B：0.5％～4％

Boron (B) is an element that lowers the melting point of the cobalt-based alloy 15 to, for example, 1100 ℃ or lower by the addition thereof and improves the wear resistance of the covering layer 13 by effectively precipitating borides in the cobalt-based alloy 15. By setting the B amount to 0.5% or more, such an effect can be obtained that the denseness of the coating layer 13 can be further improved at the time of the HIP treatment and the wear resistance can be improved. On the other hand, if the amount of B exceeds 4%, the toughness of the coating layer 13 is lowered, and cracking may occur during HIP treatment, which is not preferable. In order to more reliably obtain the melting point lowering effect, the amount of B is preferably 1% or more, more preferably 1.5% or more. In order to sufficiently ensure the toughness of the covering layer 13, the B amount is preferably 3.3% or less, and more preferably 3% or less.

The rest is as follows: cobalt and impurities

Cobalt (Co) is a main component of the cobalt-based alloy 15, and is a component having the largest content in the cobalt-based alloy 15. Cobalt has relatively excellent corrosion resistance in molten metal. The content of cobalt in the cobalt-based alloy 15 is not particularly limited as long as it is larger than other components in the cobalt-based alloy 15 as described above, and is, for example, 20% to 85%, preferably 30% to 75%. By setting the cobalt content in the cobalt-based alloy 15 to 30% or more, the corrosion resistance and toughness of the coating layer 13 can be sufficiently ensured. Further, by setting the cobalt content in the cobalt-based alloy 15 to 75% or less, it is possible to sufficiently improve the corrosion resistance and wear resistance by other additive elements.

The impurities are components that can be mixed in by raw materials and other factors in the industrial production of the coating layer 13 regardless of the intention of the addition or non-addition. Such impurities may be contained in cobalt-based alloy 15 within a range that does not adversely affect overcoat layer 13.

The cobalt-based alloy 15 is described in detail above.

(constitution of the substrate)

As described above, in the member 10 for in-bath equipment according to the present embodiment, particulate carbides containing at least W or Cr are precipitated and dispersed in the cobalt-based alloy 15 (matrix), and the matrix according to the present embodiment includes a metal portion and particulate carbides 19 containing at least one type of precipitated W or Cr. More specifically, the carbide precipitated in the matrix is, for example, one selected from the group consisting of Co₃W₃C、Co₆W₆C、WC、W₂C、Cr₂₃C₆、Cr₇C₃And Cr₃C₂One or more carbides of the group consisting.

The above-described granular carbide 19 is precipitated and dispersed in the matrix, whereby the corrosion resistance of the coating layer 13 can be improved. As a result, the melting loss of the coating layer 13 can be suppressed, and the increase in the amount of wear and the frictional force can be effectively suppressed. The content of carbide precipitated in the matrix is preferably 5 to 80 vol% with respect to the entire volume of the coating layer 13. By setting the content of carbide to 5 vol% to 80 vol%, the erosion of the coating layer 13 can be further suppressed, and the increase in the amount of wear and the frictional force can be more effectively suppressed.

Since the carbide in these matrices has a chemical composition different from that of hard particles 17 described later, it can be identified by Electron Probe Microanalyzer (EPMA) analysis or the like.

The particulate carbide 19 as described above can be formed by setting the amounts of W, Cr, and C in the cobalt-based alloy 15 within the above-described ranges and performing the HIP treatment described later.

The structure of the base body of the present embodiment is explained above.

[2.2. hard particles 17]

Hard particles 17 are added to the cobalt-based alloy 15 as a matrix. The hard particles 17 include one or both of a monomer of at least one selected from the group consisting of tungsten carbide, ditungsten carbide, chromium carbide, titanium carbide, and niobium carbide, and a granulated product of a plurality of the monomers. The granulated substance is obtained by granulating the monomer using a binder such as Ni or Co.

Among the hard particles 17, tungsten carbide (WC) and ditungsten carbide (W)₂C) And titanium carbide (TiC) which is hard particles for improving the wear resistance of the coating layer 13, chromium carbide (Cr)₂₃C₆、Cr₇C₃、Cr₃C₂) The hard particles are hard particles that relax the internal stress of the coating layer 13. Among the hard particles 17, niobium carbide (NbC) is a hard particle that improves lubricity of the coating layer 13. The hard particles 17 having such characteristics may be used alone, but when used in combination, their characteristics are shown to overlap each other.

The hard particles 17 preferably have an average particle diameter of 0.001mm to 1 mm. If the average particle size is less than 0.001mm, depending on the composition of the cobalt-based alloy 15, the hard particles 17 may agglomerate and may not be uniformly mixed with the cobalt-based alloy 15 as a matrix. When the average particle diameter exceeds 1mm, pores may remain in the coating layer 13 depending on the composition of the cobalt-based alloy 15.

The average particle diameter of the hard particles 17 is more preferably 0.02mm to 0.5 mm. By setting the average particle diameter to 0.02mm to 0.5mm, the dispersibility of the hard particles 17 in the matrix can be maintained well, and the corrosion resistance and wear resistance of the coating layer 13 can be exhibited well.

The average particle diameter of the hard particles 17 may be, for example, a volume-based median diameter (D50) measured by a laser diffraction particle size distribution method after classification at a raw material stage.

In addition, the obtained manufactured hard particles may be appropriately classified, and only hard particles having a particle diameter within a predetermined range may be used as the hard particles 17 added to the coating layer 13. When fine particles are present in the cover layer 13, these particles are relatively easily detached from the cover layer 13. In addition, when relatively large particles are present, the toughness of the coating layer 13 tends to be easily lowered. By the classification, these fine particles and coarse particles can be excluded. The classification method is not particularly limited, and examples thereof include classification by sieving or an air classifier.

The content of the hard particles 17 is not particularly limited, and is preferably 15 to 70 vol% based on the entire volume of the coating layer 13. When the content of the hard particles 17 is less than 15 vol%, the area ratio of the cobalt-based alloy 15 as a matrix may be increased to lower the corrosion resistance, and the wear resistance of the coating layer 13 may be insufficient. When the content of the hard particles 17 exceeds 70 vol%, cracks may occur during the application of the coating layer 13.

The content of the hard particles 17 is more preferably 25 to 55 vol% based on the entire volume of the cover layer 13. The hard particles 17 are contained in a smaller amount, the more excellent the crack resistance, the more excellent the wear resistance, and the crack resistance and the wear resistance are in a trade-off relationship. By setting the content of the hard particles 17 to 25 vol% to 55 vol%, both the crack resistance and the wear resistance can be effectively exhibited.

When a plurality of compounds are added as the hard particles 17, the total content is preferably set within the above range.

The hard particles 17 of the present embodiment are explained in detail above.

In the member for in-bath facilities according to the present embodiment described above, the amount of carbon contained in the cobalt-based alloy is set to a predetermined range, whereby the granular carbides 19 of W or Cr are precipitated in the cobalt-based alloy, thereby improving the corrosion resistance. As a result, the melting loss of the coating layer 13 can be suppressed, and the increase in the amount of wear and the frictional force can be effectively suppressed. Therefore, the member for in-bath equipment according to the present embodiment is preferably disposed in a portion of the molten metal bath where abrasion and friction of the equipment are likely to occur. Specifically, the member for in-bath facility of the present embodiment is a roller member of the in-bath facility of the molten metal, and preferably may be a roller support shaft or a roller bearing. In addition, the in-bath facility member according to the present embodiment is suitable for a hot-dip metal material production apparatus that operates for a long time, for example, a continuous hot-dip metal material production apparatus, because an increase in the amount of wear and an increase in the frictional force accompanying a change over time are suppressed.

[2.3. method for producing Member for in-bath facility ]

Next, the method for producing the in-bath device member described above will be described mainly with respect to the method for forming the coating layer 13 in particular. Fig. 4 and 5 are explanatory views schematically showing an example of a hot isostatic pressing device (HIP device).

The in-bath device member can be obtained by forming the clad layer 13 on the base metal 11 by hot isostatic pressing (HIP treatment). The HIP treatment is performed, for example, by filling a cylindrical metal capsule (metal capsule)200 shown in fig. 4 with raw materials of the base material 11 and the coating layer 13, and then disposing and treating the metal capsule 200 in the HIP apparatus 100 shown in fig. 5.

Specifically, first, the metal capsule 200 is prepared, and as shown in fig. 4, the material powder 20 containing the cobalt-based alloy 15 as the matrix and the hard particles 17 is sealed in the space formed between the base material 11 serving as the base material and the metal capsule 200.

Next, the base material 11 and the metal jacket 200 are arranged in the HIP device 100 with the material powder 20 enclosed therein, and the HIP treatment is performed. As illustrated in fig. 5, the HIP device 100 includes a high-pressure cylinder 101, a base 103, a frame 105, a Mo heater 107, a supply pipe 109, a discharge pipe 111, and a vacuum pump (not shown).

The high-pressure cylinder 101 may be formed with a space 113 in which a plurality of metal jackets 200 can be housed in series, and the inside thereof may be set to a predetermined pressure condition. The pedestal 103 is housed in the space 113, and a rack 105 to which the Mo heater 107 is attached is disposed on the pedestal 103. The rack 105 is configured to have a plurality of shelves, and the metal wrap 200 may be disposed on each of the shelves. The Mo heater 107 is attached to the rack 105 so as to cover the periphery of the metal sheath 200 disposed on the rack 105, and heats the material powder 20 and the base material 11 together with the metal sheath 200. Thus, the Mo heater 107 functions as a heating furnace for the material powder 20 and the base material 11.

The supply pipe 109 can supply pressure medium from the outside into the space 113. As the pressure medium, an inert gas such as nitrogen gas may be used in addition to Ar gas as shown in fig. 5, and may be appropriately selected and used according to the processing conditions. The discharge pipe 111 is connected to a vacuum pump, not shown, and can discharge gas present in the space 113, for example, air and a pressure medium present before the HIP treatment, to the outside of the apparatus.

A plurality of metal capsules 200 are housed in the space 113 of the HIP device 100 as described above, and the Mo heater 107 is disposed around the metal capsules 200. Next, the space 113 is depressurized by a vacuum pump through the discharge pipe 111 so as to be in a vacuum atmosphere. Thereafter, a pressure medium, for example, Ar gas, is introduced from the supply pipe 109, and the space 113 is set to be under an Ar gas atmosphere. Then, in an Ar gas atmosphere, for example, at a pressure of 1000 to 1500kgf/cm²And carrying out HIP treatment at 1050-1250 ℃ for 1-3 hours. Further, 1kgf was about 9.8N. In the HIP process, gold is shown in FIG. 4The metal sheath 200, the base material 11 as the content, and the material powder 20 are loaded with the same pressure in each direction by the pressure medium.

Thereby, the coating layer 13 is formed on the base material 11. Here, a predetermined amount of W, Cr, and C is relatively uniformly present in the material of the cobalt-based alloy 15 of the coating layer 13, and these components relatively uniformly form nuclei in the matrix to form granular carbide. The HIP treatment described above can be performed at a relatively low temperature, and the coating layer 13 can be formed while maintaining the shape of the hard particles 17.

In contrast, when the conventionally known overlay welding method is employed, it is necessary to set the material of the coating layer to a temperature higher than the melting point of the matrix, for example, 1300 ℃ or higher, and as a result, dendrites of the cobalt-based alloy are generated in the matrix. Such dendrites are easily melted because a main portion composed of a metal phase easily melted into molten metal is thick and linear. As a result, the effect of improving corrosion resistance is insufficient when dendrites are generated, as compared with the case of generating granular carbides.

In addition, when the overlay welding method is employed, in addition to the above-described problems, selective damage (bead trace) occurs in the overlapped portion of the bead. Further, in the case of the thermal spraying method, since the obtained coating layer contains many defects, the adhesion of the coating layer is inferior to that in the case of the HIP treatment.

After the HIP treatment, the base material 11 and the coating layer 13 formed on the base material 11 may be cut out by cutting to have a desired shape. In this case, the metal jacket 200 may be cut together with the metal jacket.

By performing such a treatment, the member for in-bath facility of the present embodiment can be manufactured. The method for producing the member for in-bath facility according to the present embodiment is explained above.

Examples

Hereinafter, the members for in-bath facilities according to the embodiment of the present invention will be specifically described while showing examples and comparative examples. The examples shown below are merely examples of the member for an in-bath facility according to the embodiment of the present invention, and the member for an in-bath facility according to the embodiment of the present invention is not limited to the examples shown below.

(1. production of sleeve by HIP method)

The bushings of examples 1 to 37 and comparative examples 1 to 18 were produced according to the above-described method for producing the in-bath equipment member. The Co-based alloy and the hard particles used in the present experimental example are shown in tables 1 to 3 below. Further, the HIP treatment was carried out using the apparatus shown in FIGS. 4 and 5, using argon as a pressure medium, at 1100 ℃ under 100MPa for 2 hours.

In tables 1 to 3 below, the particle size and the 1 st order particle size of the hard particles were measured by a laser diffraction particle size distribution measurement method after classification in the raw material stage. The shape and particle size of the carbide were observed and measured by an electron microscope.

(2. production of sleeve by build-up welding method)

Next, sleeves of comparative examples 19 and 20 were produced by overlay welding. Specifically, a base material to be used as a base material is prepared, and a coating layer is formed on the base material by overlaying the base material on the outer periphery thereof in the circumferential direction by a plasma powder welding method under conditions of a welding current of 160 to 200A, a welding voltage of 20 to 25V, a welding speed of 100mm/min, and a powder amount of 25 to 30 g/min.

The configurations of the bushings of the examples and comparative examples are shown in tables 1 to 3 below.

(3. evaluation)

The bushings obtained in the examples and comparative examples were used in a continuous hot-dip metal plating apparatus, and the presence or absence of the occurrence of the slippage of the steel plate accompanying the increase in the specific wear amount and the friction coefficient was evaluated. The specific wear amount was calculated from the change in the shaft diameter of the device member in the bath before and after use. The results are shown in tables 4 and 5.

[ Table 4]

[ Table 5]

As is clear from tables 4 and 5, in the comparative examples, the specific wear amount was large, or the base material was deformed, or cracks were generated during construction, or steel plate slippage was generated, but in the examples of the present invention, the specific wear amount was small, and steel plate slippage was not generated. The results show that the embodiment of the present invention extremely well suppresses the increase in the specific friction amount and the friction coefficient, and the sleeve according to the embodiment of the present invention has excellent corrosion resistance.

In comparative examples 19 and 20 using the overlay welding method, the precipitates were not granular, and dendrites of the cobalt-based alloy were generated. Further, in comparative examples 19 and 20, since the steel plate slip occurred, it is suggested that the corrosion resistance of the sleeve is poor.

While preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention belongs can conceive various modifications and alterations within the scope of the technical idea described in the claims, and it is needless to say that these modifications and alterations are also understood as belonging to the technical scope of the present invention.

Description of the symbols:

1 molten zinc bath

2 furnace nose

3 sink roll

4 support roller

5. 6 fulcrum

11 base material

13 coating layer

15 cobalt-based alloy

17 hard particles

19 carbide

20 material powder

100 hot isostatic pressing device

101 high pressure cylinder

103 base

105 shelf

107 Mo heater

109 supply pipe

111 discharge pipe

200 metal sheath

Claims

1. A member for in-bath facilities used for molten metal in-bath facilities in a hot-dip metal material production apparatus,

the member for an in-bath device has a coating layer provided on at least a part of a surface of the member for an in-bath device,

the coating layer comprises hard particles and a matrix holding the hard particles,

the hard particles include one or both of a monomer of at least one selected from the group consisting of tungsten carbide, ditungsten carbide, chromium carbide, titanium carbide and niobium carbide, and a granulated substance obtained by granulating the monomer using a binder.

2. The member for in-bath equipment according to claim 1, wherein the base contains, in mass%, C: 1 to 2 percent.

3. The member for in-bath equipment according to claim 1 or 2, wherein the base contains, in mass%, a material selected from the group consisting of

Si：0.5％～4％

B: 0.5% -4%, and

ni: 5% to 30% of at least one of the group.

4. The member for in-bath equipment according to any one of claims 1 to 3, wherein a content of W in the matrix is 21% by mass or less, and a content of Ni is 5% or more.

5. The member for in-bath equipment according to any one of claims 1 to 4, wherein the carbide precipitated in the matrix is one containing a carbide selected from the group consisting of Co₃W₃C、Co₆W₆C、WC、W₂C、Cr₂₃C₆、Cr₇C₃And Cr₃C₂One or more carbides of the group consisting of.

6. The member for in-bath equipment according to any one of claims 1 to 5, wherein a content of carbide precipitated in the matrix is 5 to 80 vol% with respect to an entire volume of the coating layer.

7. The member for in-bath equipment according to any one of claims 1 to 6, wherein the hard particles have a particle diameter of 0.001mm to 1 mm.

8. The member for in-bath equipment according to any one of claims 1 to 7, wherein the hard particles have a particle diameter of 0.02mm to 0.5 mm.

9. The member for in-bath equipment according to any one of claims 1 to 8, wherein the content of the hard particles is 15 to 70 vol% with respect to the entire volume of the cover layer.

10. The member for an in-bath device according to claim 9, wherein a content of the hard particles is 25 to 55 vol% with respect to an entire volume of the cover layer.

11. The member for an in-bath device according to any one of claims 1 to 10, wherein the thickness of the covering layer is 1mm to (the thickness dimension of the wall of the member for an in-bath device) -7 mm.

12. The member for an in-bath device according to any one of claims 1 to 11, which is a roller member of the in-molten metal bath device.

13. The member for an in-bath apparatus according to any one of claims 1 to 12, which is a roll fulcrum or a roll bearing of the in-bath apparatus for molten metal.

14. A molten metal in-bath facility comprising the member for an in-bath facility according to any one of claims 1 to 13.

15. A hot-dip plated metal material production device provided with the member for in-bath facilities according to any one of claims 1 to 13.