JP5645696B2 - VACUUM DEVICE MEMBER AND VACUUM DEVICE MANUFACTURING METHOD - Google Patents

Description

  The present invention relates to a vacuum device member having a sufficiently low gas release amount and excellent rust resistance, and a method for producing the same.

  Generally, stainless steel such as SUS304 and SUS316L is used for the vacuum device member from the viewpoint of gas release and workability. The unevenness and rust on the surface of the vacuum device member become a gas emission source, and a high vacuum cannot be obtained. For this reason, for example, electrolytic polishing or the like is performed in a stainless steel vacuum vessel to suppress gas release.

  On the other hand, since stainless steel is expensive, it has been studied to replace it with a cheaper corrosion-resistant steel material in various applications that require corrosion resistance. In recent years, steel materials have been proposed that can provide good corrosion resistance without containing a large amount of Cr as in stainless steel (see, for example, Patent Document 1). The corrosion-resistant steel material proposed by Patent Document 1 contains 4 to 9% of Cr and is a corrosion-resistant steel material having excellent bare rust resistance.

JP 2008-127653 A

Conventionally, stainless steel vacuum device members such as SUS304 are subjected to heat treatment (SR) to remove weld distortion after welding, precision processing, and electrolysis for suppressing gas release in an electrolytic solution containing copper sulfate. It was manufactured by a method of polishing.
The present inventors examined whether it is possible to manufacture a vacuum apparatus member by a conventional manufacturing method by replacing SUS304 with a corrosion-resistant steel material. As a result, it was found that the corrosion-resistant steel material having a Cr content of 4 to 9% rusts before being transferred from the electrolytic cell to the cleaning tank in the step of electrolytic polishing.

  Therefore, in order to obtain a vacuum device member made of a corrosion-resistant steel material containing 4 to 9% Cr, in order to suppress gas emission, instead of electrolytic polishing, a gas emission source is not affected without affecting rusting. It is necessary to perform the process of removing. In addition, as a process of removing the gas emission source without affecting rusting, dry cutting performed in the atmosphere such as mechanical cutting such as milling, mechanical grinding with a grindstone or grinder, mechanical polishing with an abrasive, blasting, etc. These include a dry process, pickling to remove black skin, a citric acid treatment process that does not affect rusting, and the like, and electropolishing is not included.

  In addition, in a vacuum device member used in an air-conditioning environment such as a clean room, there is a problem of gas emission from the normal pressure side into the clean room as well as the vacuum side. Conventional stainless steel vacuum device members have extremely high corrosion resistance, and no rust, which is a gas release source, is generated on the atmospheric pressure side after production. In particular, in an air-conditioning environment, the vacuum device member is unlikely to corrode. However, as a result of the study by the present inventors, when using a corrosion-resistant steel material having a reduced Cr content compared to stainless steel, the suppression of rusting on the surface on the normal pressure side of the vacuum device member may be a problem. all right.

  A conventional vacuum device member is manufactured and then incorporated into a vacuum device under an air-conditioning environment in which the vacuum device is used via a warehouse or the like that stores the vacuum device member. Air conditioning (air conditioning) of air temperature and humidity is often not performed in a factory where a vacuum device member is manufactured or in a warehouse where it is stored. In such an indoor air environment, unlike air-conditioning environment, for example, salt caused by sweating accumulates on the surface of the vacuum device member. In addition, the storage period required for the vacuum device member to be shipped from the factory and installed in the air-conditioning environment in which the vacuum device is used may be as long as six months or longer. If the storage period of the vacuum device member is long, the amount of salt deposited on the surface of the vacuum device member may increase and rust may occur. In particular, indoor air environments such as factories and warehouses in the coastal area become corrosive environments due to the arrival of sea salt particles, and are prone to rust.

  Therefore, when replacing the material of the vacuum device member from stainless steel to an inexpensive corrosion-resistant steel material, it is necessary to improve rust resistance so that rust does not occur even in an indoor atmospheric environment. When the vacuum device member is stored in a factory or warehouse in the beach area for a long period of time, the amount of salt deposited on the surface of the vacuum device member increases, and rusting may be unavoidable. However, even in such a case, it is necessary to provide a vacuum device member having rust resistance enough to clean the surface with simple care.

  As described above, in order to use a steel material having a Cr content lower than that of stainless steel as a material for a vacuum device member used in an air-conditioning environment, a process for removing a gas emission source without affecting rusting is required. By doing so, it is required to reduce the amount of gas released from the surface disposed on the vacuum side and to improve the rust resistance of the surface disposed on the normal pressure side (exposed to the indoor atmospheric environment). .

  The present invention is made of a steel material having a Cr content lower than that of stainless steel, and can be suitably used as a vacuum device member used in an air-conditioning environment. An object of the present invention is to provide a method for manufacturing a vacuum device member having excellent properties.

In order to solve the above-mentioned problems, the present inventor is to provide a vacuum device member which is made of a steel material having a Cr content lower than that of stainless steel, has a sufficiently low gas release amount and has sufficient rust resistance. Researched earnestly.
As a result, it was found that the component composition of the steel material needs to contain both Cr: 4.0 to 9.0% and Al: 0.1 to 1.50%. Moreover, in order to suppress gas emission, the surface roughness parameter Ra of the surface arrange | positioned at a vacuum side is 0.1 or less by performing the process of removing a gas emission source, without affecting rusting. And found out that In general, when the surface of the material is smoothed, the surface area in contact with the vacuum is reduced and gas emission can be suppressed, but the present inventors experimentally reduce the gas emission amount by making Ra 0.1 or less. I found out.

  Furthermore, it was found that the surface disposed on the atmospheric pressure side must be smoothed in order to prevent rusting during a period of exposure to an indoor atmospheric environment where salt is deposited on the surface. In order to smooth the surface, it is necessary to reduce the roughness parameter Ra or to control the shape of the unevenness. The reason why the rust resistance is improved by smoothing the surface of the steel material containing both Cr: 4.0 to 9.0% and Al: 0.1 to 1.50% is not necessarily clear. This is considered to be due to the form of the oxide film formed on the surface. That is, a continuous oxide film is formed on the surface by reducing the roughness parameter Ra of the steel material with optimized components or controlling the shape of the unevenness, and the rust resistance is improved. it is conceivable that.

The present inventor conducted further earnest research, and on the surface disposed on the normal pressure side of the vacuum device member, (a) the surface roughness parameter Ra was set to 0.6 or less, and (b) the surface perpendicular to the surface. The ratio of the area having the luminance distribution of 128 or less to the area of the luminance distribution from 0 to 255 per unit area of 1.5 mm ^{2 of the} image taken by irradiating light from the direction inclined by 20 ± 5 degrees with respect to the direction is 20 It was found that it is necessary to satisfy one or both of the following: If either one or both of the above (a) and (b) is satisfied, the unevenness that is likely to be the starting point of rusting will be sufficiently small, and placed on the normal pressure side of the vacuum device member used in an air-conditioned environment. Sufficient rust resistance as a surface to be obtained is obtained.

  The present invention has been completed based on the above findings, and the gist thereof is as follows.

(1) A vacuum device member used in an air-conditioning environment, and in mass%, C: 0.005% to 0.030%, Si: 0.10% to 1.00%, Mn: 0 20% or more and less than 3.00, P: 0.030% or less, S: 0.0050% or less, Cr: 4.0% or more and 9.0% or less, Al: 0.10% or more and 1.50% or less , N: 0.020% or less, the balance comprising a part made of steel made of Fe and inevitable impurities, the one side surface exposed to the atmosphere, and the other side exposed to the vacuum space and a surface, (a) roughness parameter Ra of said one side surface of 0.60 or less, was irradiated with light from 20 ± 5 degrees inclined direction with respect to the direction perpendicular to the (b) said one side surface bright in the region from the luminance distribution 0 to 255 of the unit area 1.5 mm ² per shot image Te Distribution 128 following ratio of area of 20% or less, or satisfies either or both, for vacuum apparatus member, wherein the roughness parameter Ra of the other surface-side surface is 0.10 or less of.

(2) The steel material further includes one or two of Cu: 0.05% to 0.50% and Ni: 0.05% to 0.50% by mass%. The member for a vacuum apparatus according to the above (1).
(3) The steel material is further mass%, Mo: 0.01% to 0.20%, V: 0.005% to 0.050%, Nb: 0.005% to 0.050% The vacuum device member according to (1) or (2) above, which contains one or more of Ti: 0.005% or more and less than 0.030%.

(4) The steel material is further in mass%, Ca: 0.0005% to 0.010%, Mg: 0.0005% to 0.010%, REM: 0.001% to 0.010% The vacuum device member according to any one of (1) to (3) above, which contains one or more of the following:
(5) The vacuum device member according to any one of (1) to (4), wherein a roughness parameter Ra of the other surface is 0.03 or more.
(6) The member for a vacuum apparatus according to any one of (1) to (5) above, wherein a rusting area on the one surface side surface and the other surface side surface is 3% or less.

( 7 ) It is a manufacturing method of the member for vacuum devices provided with the components which consist of steel materials which have a component composition as described in any one of said (1)-(4), and neither electropolishing nor pickling is performed. A normal pressure side treatment step for treating the one surface side surface exposed to the atmosphere of the component, and a vacuum side treatment for treating the other surface side surface exposed to the vacuum space of the component without performing any of electropolishing and pickling. The atmospheric pressure side treatment step projects spherical particles having a Mohs hardness of 5.5 to 7.5 according to a 15-step evaluation for minerals, a mechanical cutting step, a mechanical grinding step, a mechanical polishing step, A method for producing a member for a vacuum device, wherein the vacuum side treatment step is a step of polishing using a 400-th or higher abrasive.

( 8 ) The method for producing a member for a vacuum device according to ( 7 ), wherein the spherical particles are glass beads.
( 9 ) The method for producing a member for a vacuum device according to ( 7 ) or ( 8 ), wherein the normal pressure side treatment step includes a step of treating the one surface side with citric acid.
( 10 ) The method for manufacturing a member for a vacuum device according to any one of ( 7 ) to ( 9 ), wherein the vacuum side treatment step includes a step of performing citric acid treatment on the other side surface.

The vacuum device member of the present invention includes a component made of a steel material having a predetermined component composition, and has one surface side surface where the component is exposed to the atmosphere and another surface side surface exposed to the vacuum space. a) The surface area roughness parameter Ra is 0.6 or less, and (b) the unit area of an image taken by irradiating light from a direction inclined by 20 ± 5 degrees with respect to the direction perpendicular to the one surface side surface. The ratio of the area of the luminance distribution 128 or less to the area of the luminance distribution 0 to 255 per 5 mm ² satisfies 20% or less, and the roughness parameter Ra on the other surface side is 0.1. Because it is the following, even if it is stored for 6 months or more in the indoor atmospheric environment before it is installed in the air-conditioning environment where the manufactured vacuum device member is used, it is exposed to the atmosphere. The rust resistance of the surface on the one side is sufficiently obtained. , Becomes is sufficiently small outgassing amount of other side surfaces which are exposed to the vacuum space.

  Therefore, the vacuum device member of the present invention can sufficiently prevent rust from being produced after being manufactured and used in the vacuum device, and the degree of vacuum of the vacuum device using this can be reduced. It can be made sufficiently high and can be suitably used as a vacuum device member.

FIG. 1 is a perspective view showing an example of a vacuum device member of the present invention. FIG. 2 is an example of an image of the surface of a steel material that has been subjected to mechanical cutting. FIG. 3 is an example of an image of the surface of a steel material subjected to mechanical polishing. FIG. 4 is an example of an image of the surface of a steel material that has been subjected to glass bead blasting. FIG. 5 is an example of an image of the surface of a steel material from which black skin has been removed by pickling. FIG. 6 is an example of an image of the surface of a steel material that has been subjected to ceramic blasting.

"Vacuum equipment parts"
FIG. 1 is a perspective view showing an example of a vacuum device member of the present invention. A vacuum device member 10 shown in FIG. 1 is used in an air-conditioned environment as a vacuum container (chamber) of a vacuum device. The vacuum device member 10 is exposed to an indoor atmospheric environment during manufacturing and storage, and then incorporated into a vacuum device in an air-conditioned environment and used as it is in an air-conditioned environment.

  In the present invention, the air conditioning environment means an “environment in which the temperature and humidity are controlled by the air conditioning equipment”. Moreover, it is preferable that the air-conditioning environment in the present invention is an environment in which the temperature is kept within a range of 10 to 30 ° C. and the humidity is kept within a range of 80% or less. . On the other hand, in the present invention, the “indoor atmospheric environment” is an environment that is surrounded by a roof and walls and is not exposed to wind and rain, but is not adjusted for temperature and humidity and is not cleaned of air. means. In an indoor atmospheric environment, salt is deposited on the surface of the vacuum device member due to perspiration and the arrival of sea salt particles, resulting in a corrosive environment.

  A vacuum device member 10 shown in FIG. 1 is a container having a substantially rectangular parallelepiped outer shape, and a plurality of opening holes for supplying and discharging gas into the container are provided on a wall surface. However, the shape of the vacuum device member is not limited to a substantially rectangular parallelepiped shape, and may be, for example, a substantially cylindrical shape. The vacuum apparatus member 10 is formed by integrating a plurality of components such as a plate-shaped component (component) 15 constituting a wall surface and a tubular (ring-shaped) component 13 arranged around the opening hole for attaching a piping material. It will be. The components included in the vacuum device member 10 are joined to each other by welding or the like.

  A plate-like component 15 constituting the vacuum device member 10 shown in FIG. 1 is an outer surface (a surface on the normal pressure side, also referred to as one surface side) 11 exposed to an indoor atmospheric environment and an air conditioning environment, and a vacuum. It has an inner surface (vacuum side surface, also referred to as the other surface side) 12 exposed to the space. The plate-like component 15 disposed on the wall surface of the vacuum device member 10 is made of a steel material having a predetermined component composition to be described later. On the other hand, the tubular component 13 disposed around the opening hole is preferably made of a steel material having a predetermined composition described later, but may be made of stainless steel. In addition, when the tubular component 13 consists of stainless steel, it is preferable that it is what consists of SUS304 or SUS316L from a viewpoint of workability.

  In addition, although the member for vacuum devices of this invention may consist of several components like the member 10 for vacuum devices shown in FIG. 1, from the steel material which has the predetermined component composition and surface state which are mentioned later It may be a single component. In addition, when the vacuum device member of the present invention is composed of a plurality of parts, a part of the plurality of parts, such as stainless steel different from the steel material having a predetermined component composition and surface state described later, etc. It may be made of a material.

The outer surface 11 of the plate-like component 15 shown in FIG. 1 is an image obtained by irradiating light from a direction inclined by 20 ± 5 degrees with respect to a direction having a roughness parameter Ra of 0.6 or less and / or perpendicular to the outer surface 11. Of the luminance distribution 0 to 255 per unit area of 1.5 mm ² is 20% or less (hereinafter also referred to as “shadow region ratio”). Further, the roughness parameter Ra of the inner surface 12 of the plate-like component 15 shown in FIG. 1 is 0.1 or less.

  The roughness parameter Ra in the present invention means arithmetic average roughness (JIS B0601-1994). Further, in the present invention, the surface roughness parameter Ra is obtained by summing up the absolute values of deviations from the average line to the measurement curve based on the roughness parameter measurement results using the evaluation length standard value of 4.0 mm as an example. And expressed in units of μm.

The shadow area ratio is an area of luminance distribution 0 to 255 per unit area 1.5 mm ^{2 of} an image taken by irradiating light from a direction inclined by 20 ± 5 degrees with respect to a direction perpendicular to the outer surface 11. This means the ratio of the area with the luminance distribution of 128 or less. In the present invention, the unit area for calculating the shadow area ratio is set to 1 mm ² or more in order to reduce the variation of the shadow area ratio. Further, when the cutting line is formed on the outer surface 11 or the surface of the material to be the outer surface 11, the light used for calculating the shadow area ratio is irradiated from a direction orthogonal to the cutting line in plan view.

  The method for measuring the shadow area ratio will be described more specifically. FIG. 2 shows the surface of a steel material that has been machine-cut by milling, and FIG. 3 shows the surface of a steel material that has been mechanically polished using an 80th abrasive. FIG. 4 shows a blast treatment in which spherical particles (glass beads) having a Mohs hardness of 5.5 to 7.5 according to a 15-step evaluation for minerals are projected using compressed air for 1 to 5 minutes after removing the black skin. It is the surface of the steel material which performed. FIG. 5 is an image of the surface of a steel plate that has been subjected to pickling and alkali neutralization to remove the black skin, and FIG. 6 is based on a 15-step evaluation for minerals after the removal of the black skin. It is the surface of the steel material which performed the blast process which projects the particle | grains (ceramics) whose Mohs hardness is 12 using compressed air for 1 to 5 minutes. In addition, the blast process which projects ceramics, such as an alumina and SiC, is called a ceramic blast process. FIG. 6 shows an example in which alumina is projected.

2 to 6 show luminance distributions obtained by dividing the photographing luminance per unit area of 1.5 mm ² from 0 to 255 in an image photographed by irradiating light from a direction inclined by 20 degrees with respect to a direction perpendicular to the surface. The luminance area with a luminance distribution of 128 or less and the luminance area with a luminance distribution of more than 128 are separated from each other, and the area of the luminance with a value of 128 or less is extracted. The area of each visual field in FIGS. 2 to 6 corresponds to 1.5 mm ² .

  Among the images shown in FIGS. 2 to 6, the shadow area ratio is obtained by gradually deciding the area of the white portion by the entire area and evaluating the area ratio in percent. The shadow area ratio of the steel shown in FIG. 2 is 15%, the shadow area ratio of the steel shown in FIG. 3 is 4%, and the shadow area ratio of the steel shown in FIG. 4 is 12%. Moreover, the shadow area ratio of the steel shown in FIG. 5 was 7%, and the shadow area ratio of the steel shown in FIG. 6 was 29%.

In the steel material shown in FIG. 6, since the Mohs hardness of the particles used for the blast treatment is large, the shadow area ratio exceeds 20% by the ceramic blast treatment. The upper limit of the Mohs hardness of the particles used for the blast treatment needs to be 7.5 or less.
Moreover, although the shadow area ratio of the steel materials after pickling is 20% or less, rusting occurs if neutralization is not performed immediately after pickling. When the vacuum device member is small, it is possible to shorten the time from pickling to neutralization, but when the vacuum device member is large, it is difficult to sufficiently shorten the time. It is. For this reason, pickling treatment is not preferable as a normal pressure side treatment step.

  The outer surface 11 of the plate-like component 15 shown in FIG. 1 has a roughness parameter Ra of 0.6 or less and / or a shadow area ratio of 20% or less, and the occurrence of rust on the outer surface 11 is sufficiently prevented. Is. When the roughness parameter Ra of the outer surface 11 exceeds 0.6 and the shadow area ratio exceeds 20%, the outer surface 11 is disposed on the atmospheric pressure side of the vacuum device member 10 used in the air-conditioning environment and is exposed to the atmosphere. Rust resistance as the exposed surface becomes insufficient, and rust is likely to occur on the surface exposed to the atmosphere.

  Further, the inner surface 12 of the plate-like component 15 shown in FIG. 1 has a roughness parameter Ra of 0.1 or less, and a sufficient amount of gas is released from the surface disposed on the vacuum side and exposed to the vacuum space. There are few things. If the roughness parameter Ra of the inner surface 12 exceeds 0.1, the amount of gas released from the surface exposed to the vacuum space of the vacuum device cannot be sufficiently reduced, and the pressure of the vacuum space is hardly reduced. The vacuum degree of the vacuum device may be insufficient. Note that when the roughness parameter Ra of the inner surface 12 is less than 0.03, the productivity is lowered. Therefore, the roughness parameter Ra is preferably 0.03 or more.

  Next, the component composition of the steel material constituting the plate-like component (component) 15 of the vacuum device member 10 will be described. In the present invention, the steel material used for the plate-like component 15 contains the following elements in the following contents, and the balance has a component composition consisting of Fe and inevitable impurities. In the following description, “%” means “% by mass” unless otherwise specified.

“C: 0.005% or more and 0.030% or less”
C is an element that improves the strength of the steel material and needs to be contained by 0.005% or more. However, when there is too much content of C, a carbide | carbonized_material will be formed and corrosion resistance will be inhibited. For this reason, the upper limit of C content is made 0.030%. In consideration of the balance between strength, toughness, and weldability, 0.005 to 0.025% is preferable. Furthermore, if considering the production stability, 0.010% or more and 0.020% or less is preferable.

“Si: 0.10% to 1.00%”
It is effective to contain Si as a deoxidizer and a strengthening element. When the Si content is less than 0.10%, a sufficient deoxidation effect cannot be obtained. On the other hand, when the Si content exceeds 1.00%, the effects as a deoxidizer and a strengthening element are saturated. Therefore, the content of Si contained in the steel material is limited to 0.10% or more and 1.00% or less. Moreover, in order to raise the intensity | strength of steel materials, it is preferable to add Si 0.15% or more, and addition of 0.18% or more is more preferable. On the other hand, in order to ensure toughness, the upper limit of the Si content is preferably 0.80% or less, and more preferably 0.50% or less.

“Mn: 0.20% or more and less than 3.00%”
Mn is an element that improves the strength, and 0.20% or more is added. Further, since Mn acts as an austenite forming element and has an effect of suppressing the formation of coarse ferrite, 0.50% or more is preferably added. Further, when a large amount of ferrite forming elements such as Cr and Al are contained and a ferrite single phase structure is formed, cracking of the slab may occur and the productivity may be lowered, so that Mn is contained in an amount of 1.00% or more. It is more preferable. However, if Mn is contained in an amount of 3.00% or more, the ductility of the base material is remarkably lowered, so the Mn content is less than 3.00%. In view of the strength and workability of the steel material, it is preferably 1.50% or more and less than 2.80%, and more preferably 2.00% or more and 2.60% or less.

“P: 0.030% or less”
When P is present in a large amount, there is a concern that the ductility is lowered and the productivity is lowered. Therefore, it is desirable that the content of P contained in the steel material is small, and the P content is 0.030% or less.

“S: 0.0050% or less”
When S is present in a large amount, the pitting corrosion resistance is lowered. Therefore, the content of S contained in the steel material is desirably small, and the S content is set to 0.0050% or less. In consideration of the balance between pitting corrosion resistance and manufacturability, 0.0030% or less is preferable.

“Cr: 4.0% to 9.0%”
Cr needs to contain 4.0% or more in order to ensure corrosion resistance. However, even if the content of Cr exceeds 9.0%, not only the cost increases but also the toughness is impaired. Therefore, the content of Cr contained in the steel material is set to 9.0% or less. In consideration of manufacturability, weldability, and workability of the steel material, 5.0% to 7.5% is preferable. Further, considering the balance with economy, it is preferably 5.5% or more and 6.5% or less.

“Al: 0.10% or more and 1.50% or less”
Al is an important element along with Cr in order to ensure corrosion resistance. Al needs to be contained by 0.10% or more in order to ensure corrosion resistance. In order to improve corrosion resistance, it is preferable to add Al 0.20% or more, and more preferably 0.50% or more. However, if Al is contained in an amount exceeding 1.50%, the temperature range of the ferrite phase transformation is widened, which causes slab cracking in the manufacturing process. Therefore, the upper limit of the content of Al contained in the steel material is limited to 1.50% or less. Furthermore, considering the workability and production stability, the upper limit of the Al content is preferably 1.30% or less, and more preferably 1.20% or less in consideration of the balance with economy.

“N: 0.020% or less”
N, when added in a large amount, inhibits ductility and corrosion resistance due to formation of nitrides and the like. For this reason, content of N contained in steel materials shall be 0.020% or less. In consideration of corrosion resistance, economy, and workability, it is preferably 0.015% or less.

Furthermore, in the present invention, the following elements can be selected and added.
“Cu: 0.05 to 0.50%, Ni: 0.05 to 0.50%”
Both Cu and Ni are effective in improving strength and suppressing ferrite formation. Furthermore, Ni has an effect of improving ductility and toughness. In order to obtain these effects, it is preferable to contain 0.05% or more of Cu and / or Ni. However, Cu and Ni both cause embrittlement when contained over 0.50%. For this reason, it is preferable that both content of Cu and Ni contained in steel materials is 0.05 to 0.50%. Furthermore, considering corrosion resistance, manufacturability, and workability for both Cu and Ni, the content is preferably set to 0.10 to 0.30%.

“Mo: 0.01% or more and 0.20% or less”
Mo is an element in which the effect of suppressing the occurrence and growth of pitting corrosion is observed when contained in a steel material containing Cr and Al by 0.01% or more. However, when Mo is contained exceeding 0.20%, the above effect is saturated and toughness is reduced. Therefore, the content of Mo contained in the steel material is preferably 0.01% or more and 0.20% or less. Furthermore, considering the balance of corrosion resistance, manufacturability, and workability, it is preferably 0.05% or more and 0.10% or less.

“V: 0.005% to 0.050%”
V, like Nb, is an element that improves strength without impairing corrosion resistance. The said effect is recognized by making V contain 0.005% or more. However, when V is contained in a large amount, ductility is inhibited as is well known. Therefore, the content of V contained in the steel material is preferably 0.005% or more and 0.050% or less.

“Nb: 0.005% or more and 0.050% or less”
Nb is an element that improves strength and toughness without impairing corrosion resistance. The said effect is recognized by containing Nb 0.005% or more, but if it exceeds 0.050%, the effect is saturated. Therefore, the content of Nb contained in the steel material is preferably 0.005% or more and 0.050% or less.

“Ti: 0.005% or more and less than 0.030%”
Ti is an element that contributes to refinement of the crystal grain size at high temperature through the formation of nitrides, and is an element that contributes to improvement of ductility without impairing corrosion resistance. The said effect is recognized by containing Ti 0.005% or more. However, when Ti is contained in an amount of 0.030% or more, a large amount of carbide precipitates, and on the contrary, ductility is inhibited. Therefore, the content of Ti contained in the steel material is preferably 0.005% or more and less than 0.030%.

“Ca: 0.0005% to 0.010%, Mg: 0.0005% to 0.010%”
Ca and Mg are elements that can improve corrosion resistance in steels containing Cr and Al. The said effect is recognized by containing 0.0005% or more of Ca and / or Mg. However, when the content of Ca and / or Mg exceeds 0.010%, not only the effect is saturated, but also a tendency for ductility and toughness to decrease is revealed. Therefore, it is preferable that the content of Ca and Mg contained in the steel material is 0.0005% or more and 0.010% or less.

“REM (rare earth element): 0.001% to 0.010%”
Rare earth elements (REM) are elements that can improve ductility without impairing corrosion resistance. In order to acquire the said effect, it is preferable to make content of REM 0.001% or more. However, if the content of REM is large, the above effect is inhibited. Therefore, the REM (rare earth element) content contained in the steel material is preferably 0.001% or more and 0.010% or less.

"Manufacturing method for vacuum equipment components"
In the present embodiment, as an example of the method for manufacturing a vacuum device member of the present invention, a method for manufacturing the vacuum device member 10 shown in FIG. 1 will be described as an example. Normally, the vacuum device member of the present invention is manufactured in an indoor atmospheric environment. Since the vacuum device member made of the corrosion-resistant steel material of the present invention has been found to be a problem of rusting due to electrolytic polishing, unlike the conventional vacuum device member made of SUS304, the surface state is machine cutting, mechanical grinding, Adjust by mechanical polishing or blasting.

  In order to manufacture the vacuum device member 10 shown in FIG. 1, first, each component constituting the vacuum device member 10 is formed. In the present embodiment, only a method for forming a component made of a steel material having the above-described predetermined component composition and surface state will be described as a method for manufacturing the component constituting the vacuum device member 10. In addition, the parts which can use materials other than the steel material which has the predetermined component composition and surface state mentioned above, such as the tubular part 13 arrange | positioned around the opening hole, are formed by the conventional method. For example, a commercial product made of SUS304 or SUS316 may be used as the tubular part 13.

  In order to form the plate-like component 15 of the vacuum device member 10 of the present invention, first, a steel plate having the above-described component composition is prepared. The steel sheet is manufactured by heating a steel slab having the above-described composition of the steel material, followed by hot rolling, and performing a heat treatment process such as quenching, tempering, or normalizing as necessary. Steel slabs used for the production of steel sheets are manufactured by processes such as continuous casting and ingot-making / bundling after components are adjusted and melted by a converter or electric furnace.

  In addition, when the member 10 for vacuum devices contains the tubular component which consists of steel materials which have the predetermined component composition and surface state which were mentioned above, it replaces with the steel plate which has the component composition of the steel materials mentioned above, or the steel materials mentioned above In addition to the steel plate having the above component composition, a steel pipe having the above-described steel component composition is prepared. The steel pipe can be manufactured by heating a steel slab having the above-described composition of the steel material, followed by hot rolling, and performing a heat treatment step such as quenching, tempering or normalizing as necessary.

  Since a black skin is usually formed on the surface of the steel plate and / or steel pipe thus obtained, any one of mechanical cutting, mechanical grinding, and pickling is performed to remove the black skin. In order to increase productivity when removing the black skin, it is preferable to perform pickling. In the pickling in the present invention, the method using a pickling solution composed of nitric acid and hydrofluoric acid used in SUS304 or the like has a too high dissolution rate. As pickling of the steel plate and / or steel pipe in the present invention, for example, the surface is degreased and washed with an alkaline solution, then dipped in a pickling solution such as hydrochloric acid for several hours to remove the black skin, and then washed with an alkaline solution. It is preferable to use a method of sum processing.

  Next, in this embodiment, the shape processing process of the member 10 for vacuum devices is performed. In the shape processing step, first, a steel plate and / or a steel pipe is cut into a predetermined shape so as to have a shape corresponding to each component constituting the vacuum device member 10, and bending or welding is performed as necessary. And each part is formed. Next, all the parts constituting the vacuum device member 10 are joined together by welding or the like to form a shape corresponding to the vacuum device member 10. In addition, when welding is performed in the shape processing step, a stress removing step such as heat treatment is performed as necessary to remove stress such as welding strain applied to each component.

  Next, in this embodiment, precision shape processing is performed, and the shape of the member formed by the shape processing step is the shape of the vacuum device member 10 shown in FIG. By this, it becomes a member for vacuum devices provided with the plate-shaped component 15 which consists of steel materials which have the component composition mentioned above. Note that the precision shape processing may be omitted if the shape of the vacuum device member can be formed with sufficient dimensional accuracy by the shape processing step. Moreover, you may perform a precise shape process after the normal pressure side process process and / or the vacuum side process process demonstrated below. Corrosion-resistant steel materials composed of the above components are extremely susceptible to rusting when wet treatment such as electrolytic polishing and pickling is performed. Therefore, the normal pressure side treatment process and the vacuum side treatment process are performed by mechanical cutting, mechanical grinding, mechanical polishing and blasting. It is performed by dry processing such as processing.

  Next, in the present embodiment, a normal pressure side treatment process is performed for treating the surface of the plate-like component (component) 15 exposed to the atmosphere. The normal pressure side treatment step is a blast treatment for projecting spherical particles having a Mohs hardness of 5.5 to 7.5 according to a 15-step evaluation for minerals, a step of mechanically cutting the outer surface 11, a step of mechanical grinding, a step of mechanical polishing. It is a process including any one or two or more. By performing the normal pressure side processing step, the outer surface 11 of the plate-like component 15 shown in FIG. 1 has a surface roughness parameter Ra of 0.6 or less and / or a shadow area ratio of 20% or less. .

Specific examples of the process of mechanically cutting the outer surface 11 include a method of cutting the outer surface 11 using a machine tool such as a milling machine. Specific examples of the process of mechanically grinding the outer surface 11 include a method of grinding the outer surface 11 using a machine tool such as a grindstone or a grinder. The step of mechanically polishing the outer surface 11 includes a method of polishing the outer surface 11 using an abrasive. By mechanically cutting or grinding the outer surface 11, the roughness parameter Ra of the outer surface 11 can be reduced to 0.6 or less easily and efficiently.
Further, when the outer surface 11 is subjected to a blasting process for projecting spherical particles having a Mohs hardness of 5.5 to 7.5 according to a 15-step evaluation for minerals, the outer surface 11 can be easily and efficiently produced regardless of the shape of the outer surface 11. 11 shadow area ratio can be 20% or less.

  The Mohs hardness of the spherical particles used in the blasting process affects the time required for the blasting process and the shadow area ratio of the outer surface after the blasting process. When the Mohs hardness of the spherical particles is 5.5 or more, the time required for the blasting process can be shortened, and the productivity can be increased. If the Mohs hardness of the spherical particles used for the blasting process is too hard, the impact on the outer surface 11 by the blasting process becomes too strong, and the shadow area ratio of the outer surface 11 may increase. When the Mohs hardness of the spherical particles is 7.5 or less, the shadow area ratio of the outer surface 11 can be sufficiently reduced.

  The spherical particles used in the blast treatment are preferably glass beads. When the spherical particles are glass beads, even if the glass beads remain on the outer surface 11, it is difficult to cause rusting of the outer surface 11, which is preferable. The blasting process for projecting glass beads is referred to as glass bead blasting process.

  Further, in the present embodiment, the atmospheric pressure side treatment step is performed after any one or more of the step of mechanically cutting the outer surface 11, the step of mechanical grinding, the step of mechanical polishing, and the blast treatment, after the outer surface 11 is quenched. It is preferable to include a step of acid treatment. As a result, the outer surface 11 disposed on the atmospheric pressure side and exposed to the atmosphere becomes smoother, the shadow area ratio of the outer surface 11 is further reduced, and the rust resistance of the outer surface 11 is further improved. Can do.

  Next, in the present embodiment, a vacuum side processing step is performed for processing the inner surface 12 exposed to the vacuum space of the plate-like component (component) 15. Thus, the plate-like component 15 is made of the steel material having the predetermined component composition and the surface state described above, and the vacuum device member 10 of the present embodiment is obtained.

  The vacuum processing step is a step of polishing the inner surface 12 using a 400th or higher abrasive. By performing the vacuum processing step, the roughness parameter of the inner surface 12 shown in FIG. 1 is set to Ra 0.1 or less. For example, in the vacuum side processing step, the roughness parameter Ra of the inner surface 12 can be easily set to 0.03 or more and 0.1 or less by polishing using an 800-number abrasive.

  Moreover, it is preferable that a vacuum side process process is a process including the process of further citric-acid-treating the inner surface 12 after the process of grind | polishing the inner surface 12 using a 400 or more-number abrasive | polishing agent. In this case, the processing edge formed by polishing the inner surface 12 with 400 or more abrasives can be removed by citric acid treatment. As a result, the inner surface 12 arranged on the vacuum side and exposed to the vacuum space becomes smoother, and the roughness parameter Ra of the inner surface 12 becomes even smaller. As a result, the amount of gas released from the inner surface 12 can be further reduced.

  In addition to the plate-like component 15, when there is a component made of steel having the above-described predetermined component composition and surface state, the steps from the normal pressure side processing step to the next vacuum device assembly step are the same as those of the plate-like component 15. Thus, it can be performed simultaneously with the plate-like component 15. In this case, the vacuum device member 10 can be efficiently manufactured, which is preferable. In the present embodiment, the mode in which the vacuum side processing step is performed after the normal pressure side processing step has been described, but the vacuum side processing step may be performed first.

  Next, a vacuum device assembly process is performed, and the vacuum device member 10 shown in FIG. 1 is incorporated as a vacuum container of the vacuum device. Thereby, a vacuum apparatus provided with the member 10 for vacuum apparatuses of this embodiment is obtained. Moreover, the vacuum apparatus provided with the member 10 for vacuum apparatuses is installed and used in a clean room etc.

  In addition, after manufacturing the member 10 for vacuum devices obtained in the manufacturing method of this embodiment, it is normally stored in an indoor atmospheric environment. If the amount of salt deposited on the surface of the vacuum device member 10 is significantly increased, it becomes difficult to suppress rusting. Therefore, if the storage period is long, it is incorporated into the vacuum device after production and the use of the vacuum device is started. Until then, it is preferable to place it in an air-conditioned environment. This effectively prevents rust from being generated in the vacuum device member 10 after the vacuum device member 10 is manufactured and before the vacuum device including the vacuum device member 10 is actually used. Can be prevented.

In the present embodiment, the shape processing step, the normal pressure side processing step, the vacuum side processing step, and the vacuum device assembly step of the vacuum device member 10 are performed in this order. However, the present invention is not limited to this order. Can be changed as appropriate. For example, the vacuum side treatment step may be performed before the normal pressure side treatment step. Moreover, you may perform a normal pressure side process process and a vacuum side process process before a shape processing process. However, when heat treatment for removing welding distortion is performed in the shape processing step, an oxide film is generated depending on the heat treatment atmosphere. Therefore, it is preferable to perform a normal pressure side processing step and a vacuum side processing step after the shape processing step.
Also, parts that do not require corrosion resistance and slightly outgassing, such as flange surfaces of vacuum equipment members, and that require machining accuracy are preferably finished by machine cutting or machine grinding. Masking is required when blasting is performed. Preferably it is done.

  The vacuum device member 10 of the present embodiment includes a plate-like component 15 made of a steel material having a predetermined component composition, an outer surface 11 where the plate-like component 15 is exposed to the atmosphere, and an inner surface 12 exposed to the vacuum space. The roughness parameter Ra of the outer surface 11 is 0.6 or less and / or the shadow area ratio of the outer surface 11 is 20% or less, and the roughness parameter Ra of the inner surface 12 is 0.1 or less. The gas release amount is sufficiently small, and the rust resistance of the outer surface 11 is sufficiently obtained. Therefore, the vacuum device member 10 of the present embodiment can be suitably used as the vacuum device member 10.

Hereinafter, the effect of the present invention will be described in detail with reference to examples.
Steels having the composition shown in Tables 1 to 3 were melted and cast, and the obtained steel pieces were hot-rolled to produce steel plates having a thickness of 10 mm, and some of the steel plates were subjected to heat treatment (annealing). did. The annealing temperature was 550 ° C. and the holding time was 40 minutes. A test piece having a length of 200 mm, a width of 150 mm, and a thickness of 10 mm was collected from the obtained steel material. Thereafter, the test piece was pickled to remove the black skin formed on the surface. The pickling was performed by a method of neutralizing the surface after washing the surface with hydrochloric acid. Next, some test pieces shown in Tables 4 to 6 were annealed to simulate welding distortion removal.

  Next, the one side of the test piece was subjected to the normal pressure side treatment shown in Tables 4 to 6, and the other side of the test piece was subjected to the vacuum side treatment shown in Tables 4 to 6 to prepare Rust was evaluated. Moreover, the vacuum side process shown to Table 4-Table 6 was given to both surfaces and the side surface of the test piece, and gas release property was evaluated. However, as a result of conducting a tensile test and a Charpy impact test, the evaluation of rust resistance and gas release properties for a test piece having insufficient strength, ductility, and toughness was excluded.

  As the normal pressure side treatment, as shown in Tables 4 to 6, any one or more of mechanical cutting, mechanical grinding, blasting, and mechanical polishing were performed. No treatment was performed, or only blast treatment (ceramic blast treatment) for projecting alumina was performed. The blasting treatment was performed by projecting spherical particles (glass beads) having a Mohs hardness of 5.5 to 7.5 according to a 15-step evaluation for minerals using compressed air for 1 to 5 minutes to perform glass bead blasting treatment. Is indicated by “◯”, ceramic blasting using alumina having a high Mohs hardness is indicated by “×”, and those not performed are indicated by blanks. Further, as shown in Tables 4 to 6, some test pieces were subjected to citric acid treatment (indicated by “◯” in Tables 4 to 6).

After the atmospheric pressure side treatment step, the surface roughness parameter Ra and the shadow area ratio were measured. Ra is in accordance with JIS B0601-1994, and the absolute value of the deviation from the average line to the measurement curve is summed from the roughness parameter measurement results using the evaluation length standard value of 4.0 mm as an example. did. The shadow area ratio is a luminance distribution of 128 or less in an area of luminance distribution 0 to 255 per unit area 1.5 mm ^{2 of} an image taken by irradiating light from a direction inclined 20 degrees with respect to a direction perpendicular to the surface. It calculated | required by calculating the ratio which the area | region occupied.

As vacuum side treatment, “○” indicates that mechanical polishing is performed using 400 or more abrasives, “×” indicates that 200 or less abrasives are used, and blanks indicate that nothing is performed. Indicated. Furthermore, as shown in Tables 4 to 6, some of the test pieces were subjected to a citric acid treatment step (indicated by “◯” in Tables 4 to 6).
After the vacuum side treatment step, the surface roughness parameter Ra was measured in the same manner as after the normal pressure side treatment step.
Tables 4 to 6 show the measurement results of the types of normal pressure side treatment and vacuum side treatment, roughness parameter Ra, and shadow area ratio.

  For the evaluation of rust resistance, the test piece with the atmospheric pressure side treatment process on one side and the vacuum side treatment process on the other side was used to test the "indoor warehouse exposure test" and "air conditioning environment exposure test". Carried out. The indoor warehouse exposure test was evaluated by exposing to an indoor warehouse about 20m from the coast for one year. In the air conditioning environment exposure test, after exposure to a first atmosphere at a temperature of 25 ° C. and a humidity of 50% for 1 hour in a constant temperature and humidity chamber, a second atmosphere of a temperature of 50 ° C. and a humidity of 90% is gradually applied over 30 minutes. 720 cycles of a 3 hour / cycle corrosion test in which the sample was exposed to the second atmosphere for 1 hour and then gradually exposed to the first atmosphere for 30 minutes. A rusting area of 3% or less was marked with “◯”, and a rusting area exceeding 3% was marked with “x”.

Moreover, the vacuum side treatment process was given to both surfaces and the side surface of the test piece, and gas-release property evaluation was implemented using the test piece processed on the conditions of the "air-conditioning environment exposure test". The gas releasing property was evaluated by holding the test piece in vacuum (1 × 10 ⁻⁵ Pa or less), heating to 250 ° C., and performing mass analysis of the released gas. A mass spectrometer was a quadrupole mass spectrometer. As a pretreatment for the gas release test, the test piece was ultrasonically washed in acetone to degrease the surface, kept in vacuum for 2 hours, heated at 400 ° C., cooled for 60 minutes, The sample was left in the atmosphere for 5 minutes, and the moisture absorption conditions were the same. In the evaluation of gas releasing property, “◯” indicates that the amount of gas released is 1.3 times or less of the amount of gas released from SUS304 steel having a surface roughness parameter Ra of 0.06, and “×” indicates that the amount exceeds that. The results are shown in Tables 7-9.

As shown in Tables 1, 2, 4, 5, 7, and 8, the composition of the steel sheet is within the scope of the present invention, and the test piece subjected to the normal pressure side treatment step and the vacuum side treatment step under appropriate conditions, The roughness parameter Ra and the shadow area ratio were within the scope of the present invention, and the evaluation of rust resistance and gas release was evaluated as “good”.
On the other hand, as shown in Tables 3, 6, and 9, when the component composition of the steel sheet is out of the scope of the present invention or the normal pressure side treatment step and / or the vacuum side treatment step is not properly performed, the rust resistance evaluation is performed. And / or evaluation of gas releasing property was x.

  DESCRIPTION OF SYMBOLS 10 ... Vacuum apparatus member, 11 ... Outer surface (one surface side surface), 12 ... Inner surface (other surface side surface), 13 ... Tubular component, 15 ... Plate-shaped component (component).

Claims (10)

A vacuum device member used in an air-conditioning environment.
C: 0.005% or more and 0.030% or less,
Si: 0.10% or more and 1.00% or less,
Mn: 0.20% or more and less than 3.00,
P: 0.030% or less,
S: 0.0050% or less,
Cr: 4.0% or more and 9.0% or less,
Al: 0.10% or more and 1.50% or less,
N: 0.020% or less, the balance comprising a component made of a steel material consisting of Fe and inevitable impurities,
The one side surface where the part is exposed to the atmosphere, and the other side surface exposed to the vacuum space,
(A) The roughness parameter Ra of the one surface side surface is 0.60 or less,
(B) Luminance among regions from luminance distribution 0 to 255 per unit area 1.5 mm ^{2 of} an image taken by irradiating light from a direction inclined by 20 ± 5 degrees with respect to the direction perpendicular to the one surface side surface The proportion of the area of distribution 128 or less is 20% or less,
Any one or both of the above are satisfied, and the roughness parameter Ra of the surface on the other surface side is 0.10 or less. The steel material is further in mass%,
Cu: 0.05% or more and 0.50% or less,
The vacuum apparatus member according to claim 1, wherein Ni: 0.05% or more and 0.50% or less is contained. The steel material is further in mass%,
Mo: 0.01% or more and 0.20% or less,
V: 0.005% or more and 0.050% or less,
Nb: 0.005% or more and 0.050% or less,
The member for a vacuum apparatus according to claim 1 or 2, characterized by containing one or more of Ti: 0.005% or more and less than 0.030%. The steel material is further in mass%,
Ca: 0.0005% or more and 0.010% or less,
Mg: 0.0005% or more and 0.010% or less,
REM: 0.001% or more and 0.010% or less of 1 type or 2 types or more are contained, The member for vacuum devices as described in any one of Claims 1-3 characterized by the above-mentioned.   The vacuum device member according to any one of claims 1 to 4, wherein a roughness parameter Ra of the other surface is 0.03 or more. 6. The vacuum device member according to claim 1, wherein a rusting area of the one surface side surface and the other surface side surface is 3% or less. It is a manufacturing method of a member for vacuum equipment provided with parts which consist of steel materials which have the ingredient composition according to any one of claims 1 to 4.
Without performing either electropolishing or pickling, the normal pressure side treatment step for treating the surface of the part exposed to the atmosphere, and without performing electropolishing and pickling, the vacuum space of the part A vacuum side processing step for processing the exposed other surface,
The normal pressure side treatment step is any one of a mechanical cutting step, a mechanical grinding step, a mechanical polishing step, and a blast treatment for projecting spherical particles having a Mohs hardness of 5.5 to 7.5 according to a 15-step evaluation for minerals. 1 or 2 or more, The said vacuum side process process is a process of grind | polishing using the 400th or more abrasive | polishing agent, The manufacturing method of the member for vacuum devices characterized by the above-mentioned. The method of manufacturing a member for a vacuum apparatus according to claim 7 , wherein the spherical particles are glass beads. The method for manufacturing a member for a vacuum apparatus according to claim 7 or 8 , wherein the normal pressure side treatment step includes a step of citric acid treatment of the one surface side surface. The method for manufacturing a member for a vacuum apparatus according to any one of claims 7 to 9 , wherein the vacuum side treatment step includes a step of performing citric acid treatment on the other side surface.