Glass-coated product

Abstract

To provide a glass-coated product capable of preventing progression of peeling from an edge portion of a glass layer.SOLUTION: A glass-coated product in which a glass layer (GL) is baked onto a surface of a metal product, wherein the metal product has a base portion (BP) made of iron-based metal and a high corrosion-resistant portion (HP) made of a highly corrosion-resistant metal with a content of at least one of nickel and chromium that is higher than that of the iron-based metal, and the surface of the metal product is provided with a high corrosion-resistant surface (SH) which is the surface of the high corrosion-resistant portion (HP), the high corrosion-resistant portion (HP) having one side that is the high corrosion-resistant surface (SH) and the other side opposite to the high corrosion-resistant surface (SH) being the bonding surface (CF) with the base portion (BP), and when cut in a plane perpendicular to the high corrosion-resistant surface (SH), a plate-like area (PA) having a cross-sectional shape that is elongated horizontally is provided, and the glass layer (GL) is baked onto the metal product so as to cover part or all of the plate-like area (PA).SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a glass-coated product in which a glass layer is baked onto the surface of a metal product. [Background technology]

[0002] Conventionally, glass-coated products, such as enamel products, in which a glass layer is baked onto the surface of metal products, have been widely used. Among enamel products, glass-lined products are widely used as components of facilities where chemical processes are carried out. Glass-lined products are required to have excellent corrosion resistance due to their applications. In addition, general-purpose enamel products other than glass-lined products (hereinafter also referred to as "general-purpose enamel products") used in building materials such as bathtubs and wall panels and cooking utensils such as pots and kettles are also required to have excellent corrosion resistance because corrosion of the underlying metal product can cause the glass layer to peel off or cause a deterioration in aesthetics due to rust.

[0003] In a glass-coated product, the surface of a metal product usually has an exposed surface that is not covered with a glass layer and is exposed to the surface of the glass-coated product, and a glass-coated surface that is covered with a glass layer. That is, in a glass-coated product, the edge of the glass layer defines the boundary between the exposed surface of the metal product and the glass-coated surface.

[0004] In this type of glass-coated product, if the metal product is made of a metal with excellent corrosion resistance, the glass-coated product will also exhibit excellent corrosion resistance. In this regard, for example, it is known that the corrosion resistance of iron-based metals can be improved by adding a large amount of chromium. Nickel-based alloys are also known to have better corrosion resistance than general iron-based metals. However, these highly corrosion-resistant metals with excellent corrosion resistance may be more expensive or less workable than general iron-based metals. Therefore, as shown in Patent Document 1 below, in conventional glass-coated products, only the part where the edge of the glass layer, which is likely to be the starting point of peeling of the glass layer, is located is made of a highly corrosion-resistant metal. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2-125729 Summary of the Invention [Problem to be solved by the invention]

[0006] There are cases where the progress of peeling from the edge of the glass layer cannot be sufficiently suppressed even by using measures such as those in Patent Document 1, and improvements are required. Therefore, an object of the present invention is to provide a glass-coated product that can prevent the progress of peeling from the edge of the glass layer. [Means for solving the problem]

[0007] As a result of extensive research into solving the above problems, the inventors discovered that in locations where the interface between a highly corrosion-resistant metal and an iron-based metal is nearly perpendicular to the surface of a metal product, excessive stress can be applied to the glass layer due to the difference in linear expansion coefficients between the highly corrosion-resistant metal and the iron-based metal, and that the presence of such an interface in a close location can create a situation in which the glass layer is prone to peeling, which led to the completion of the present invention.

[0008] In order to solve the above problems, the present invention provides: A glass-coated product in which a glass layer is baked onto the surface of a metal product, The metal product comprises a base portion made of an iron-based metal, and a highly corrosion-resistant portion made of a highly corrosion-resistant metal having a higher content of at least one of nickel and chromium than the iron-based metal, A highly corrosion-resistant surface, which is a surface of the highly corrosion-resistant portion, is provided on a surface of the metal product, The highly corrosion resistant portion includes: a plate-like region is provided, the plate-like region having a highly corrosion-resistant surface on one side and a joint surface with the base portion on the other side opposite the highly corrosion-resistant surface, the plate-like region having a cross section that is a horizontally elongated band shape when cut along a plane perpendicular to the highly corrosion-resistant surface; The glass layer is baked onto the metal product to cover part or all of the plate-like area, providing a glass-coated product. Effect of the Invention

[0009] According to the present invention, a glass coating product can be provided that can prevent the progression of peeling from the edges of a glass layer. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of a reaction vessel made of a glass-lined product. [Diagram 2] FIG. 2 is a schematic diagram showing a cover member which is a glass-lined product. [Figure 3a] FIG. 3a is a schematic perspective view showing a metal ring that serves as the base of the protection ring. [Figure 3b] FIG. 3b is a schematic diagram showing a primary part used in the manufacture of a metal ring that serves as the base of a protection ring. [Figure 4a] FIG. 4a is a schematic diagram showing a method for manufacturing a metal ring that serves as the base of a protection ring. [Figure 4b] FIG. 4b is a schematic diagram showing a method for manufacturing a metal ring that serves as the base of the protection ring. [Figure 4c] FIG. 4c is a schematic diagram showing a manufacturing method of the metal ring that serves as the base of the protection ring. [Diagram 5] FIG. 5 is a schematic perspective view showing a metal ring that serves as a base of the protection ring. [Figure 6a] FIG. 6a is a schematic plan view showing a metal ring that serves as the base of the protection ring. [Figure 6b] FIG. 6b is a schematic plan view showing the protection ring. [Figure 7a] FIG. 7a is a schematic cross-sectional view showing the cross-section of the protection ring. [Figure 7b]FIG. 7b is a schematic cross-sectional view showing the cross-section of a protection ring with a different arrangement of glass layers. [Figure 7c] FIG. 7c is a schematic cross-sectional view showing the cross-section of a protection ring with a different arrangement of glass layers. [Figure 7d] FIG. 7d is a schematic diagram showing a method for determining the flatness of a plate-like region. [Figure 7e] FIG. 7e is a schematic diagram showing a method for determining the flatness of a plate-like region having another cross-sectional shape. [Figure 8a] FIG. 8a is a schematic cross-sectional view showing the cross-section of another protection ring. [Figure 8b] FIG. 8b is a schematic diagram showing a method for determining the flatness of the plate-like region in the protection ring shown in FIG. 8a. [Figure 9] FIG. 9 is a schematic cross-sectional view showing the cross-section of another protection ring. [Figure 10] FIG. 10 is a schematic cross-sectional view showing the cross-section of the container nozzle. [Figure 11a] FIG. 11a is a schematic cross-sectional view showing a cross-section of another container nozzle. [Figure 11b] FIG. 11b is a schematic diagram showing a method for determining the flatness of the plate-like region in the container nozzle shown in FIG. 11a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to specific glass-lined products. However, the glass-coated product of the present invention may be a glass-lined product other than those exemplified below, or may be a general-purpose enamel product other than a glass-lined product, or may be other than those.

[0012] The following describes a reaction tank as an embodiment of the present invention. The reaction tank 1 illustrated in the figure is a vertical tank. The reaction tank 1 has a tank body 10 with a storage space 10c for storing reactants. The tank body 10 has an opening at the top for communicating the storage space 10c with the space outside the tank. The reaction tank 1 of this embodiment further has a cover member 20 that closes the opening of the tank body 10. The tank body 10 and the cover member 20 are each a glass-lined product. That is, the reaction tank 1 illustrated in FIG. 1 is composed of multiple glass-lined products.

[0013] 1 and 2, in this embodiment, a metal product (metal vat 100) that is machined to have a shape corresponding to the vat body 10 serves as the base of the vat body 10. The vat body 10 is composed of the metal vat 100 and a glass layer GL that is baked onto the metal vat 100. The lid member 20 also has a metal product (metal lid material 200) as its base, and is equipped with the metal lid material 200 and a glass layer GL that is baked onto the metal lid material 200.

[0014] The metal vat 100 includes a metal vat body 1100 which becomes the main body portion 110 of the vat body 10 , and a metal nozzle 1200 which constitutes the container nozzle 120 of the vat body 10 .

[0015] The metal tank body 1100 has a body portion 1110 extending in a cylindrical shape in the vertical direction. The body portion 1110 in this embodiment is cylindrical. The metal tank body 1100 is arranged so that the central axis 1110c of the cylindrical body portion 1110 extends in the vertical direction, and the central axis 1110c extends in the vertical direction. The metal tank body 1100 includes a bottom portion 1120 that closes the cylindrical body portion 1110 from the lower end side, and a ceiling portion 1130 that closes the body portion 1110 from the upper end side. The bottom portion 1120 in this embodiment is a disk shape with a portion close to the central axis 1110c bulging downward, and the ceiling portion 1130 is a disk shape with a portion close to the central axis 1110c bulging upward.

[0016] In the tank body 10, a glass layer GL is baked onto the inner peripheral surface of the trunk portion 1110, the upper surface of the bottom portion 1120, and the lower surface of the ceiling portion 1130, so that metal products are not exposed to the storage space 10c.

[0017] The ceiling portion 1130 has one or more openings penetrating in the vertical direction. The metal vat 100 further includes the metal nozzle 1200, which is thinner than the body portion 1110 and extends in a cylindrical shape. As shown in FIG. 2, the metal nozzle 1200 includes a cylindrical portion 1210 that extends in a cylindrical shape upward from the opening of the ceiling portion 1130, and a flange portion 1220 that extends radially outward from the upper end of the cylindrical portion 1210. In this embodiment, the cylindrical portion 1210 is cylindrical, and the flange portion 1220 is annular. In the main body portion 110 of the vat body 10, a glass layer GL is baked on the inner circumferential surface of the cylindrical portion 1210 and the upper surface of the flange portion 1220. The glass layer GL in these portions is continuous with the glass layer GL in the ceiling portion 1130.

[0018] In this embodiment, the glass layer GL is not baked onto the lower surface of the flange portion 1220. That is, the metal vat 100 of this embodiment has a plate-shaped portion having an annular shape, the plate-shaped portion having a first surface 1220a, a second surface 1220b opposite to the first surface 1220a, and a side surface 1220c connecting the edges of the second surface 1220b and the first surface 1220a, and the glass layer GL is baked onto only the first surface 1220a of the plate-shaped portion.

[0019] As described above, the tank body 10, which is a glass-lined product, has a main body portion 110 having a shape corresponding to the metal tank body 1100, and the main body portion 110 has a trunk portion 111 that extends cylindrically in the vertical direction.

[0020] The central axis of the main body 110 coincides with the central axis 1110c of the trunk 1110 of the metal vat 100. That is, the main body 110 is arranged so that the central axis extends in the vertical direction. The main body 110 includes a bottom 112 that closes the cylindrical trunk 111 from the lower end side, and a ceiling 113 that closes the trunk 111 from the upper end side. The bottom 112 of this embodiment is also a disk shape that bulges downward, and the ceiling 113 is also a disk shape that bulges upward like the ceiling 1130 of the metal vat main body 1100.

[0021] The tank body 10 is provided with a container nozzle 120 having a shape corresponding to the metal nozzle 1200. The tank body 10 further includes a container nozzle 120 having an opening penetrating the ceiling portion 113 in the vertical direction and extending cylindrically from the opening. The container nozzle 120 includes a cylindrical portion 121 that is thinner than the body portion 111 and extends cylindrically upward from the opening of the ceiling portion 113, and an annular plate-shaped flange portion 122 that extends radially outward from the upper end of the cylindrical portion 121, with the inside of the flange portion 122 being the upper end opening.

[0022] The cover member 20, which constitutes the reaction tank 1 together with the tank body 10, is also a glass-lined product as described above. As shown in Fig. 2, the cover member 20 includes a circular plate-shaped protection ring 210 that overlaps the flange portion 122 of the vessel nozzle 120, and a cover body 220 that is shaped to overlap the protection ring 210 with its periphery aligned.

[0023] The metal lid material 200, which is a metal product constituting the lid member 20, includes a metal ring 2100 having a shape corresponding to the protection ring 210, and a metal lid 2200 having a shape corresponding to the lid main body 220. In this embodiment, the metal lid 2200 and the metal ring 2100 are joined by a hinge at one location on the outer periphery.

[0024] The annular metal ring 2100 constituting the protection ring 210 has an upper surface (first surface 2100a) facing the metal cover 2200, and a lower surface (second surface 2100b) opposite the upper surface and facing the flange portion 122 of the tank body 10. The metal ring 2100 has side surfaces (2100c1, 2100c2) connecting the edge of the first surface 2100a and the edge of the second surface 2100b. The metal ring 2100 has an outer peripheral side surface 2100c2 connecting the radially outer edge of the first surface 2100a and the radially outer edge of the second surface 2100b, and an inner peripheral side surface 2100c1 connecting the radially inner edge of the first surface 2100a and the radially inner edge of the second surface 2100b.

[0025] The gold lid 2200 has a dome-shaped base portion 2210 with a portion closer to the center than the outer periphery bulging upward. The base portion 2210 is doughnut-shaped with an opening in the center that serves as a viewing window. The gold lid 2200 has a gold lid tubular portion 2220 that extends in a cylindrical shape from the opening of the base portion 2210, and a gold lid flange portion 2230 that extends outward from the upper edge of the gold lid tubular portion 2220.

[0026] In the lid member 20, a glass layer GL is baked onto the first surface 2100a, the second surface 2100b, and the inner side surface 2100c1 of the metal ring 2100, as well as the lower surface of the substrate portion 2210 of the gold lid 2200, the inner surface of the gold lid cylindrical portion 2220, and the upper surface of the gold lid flange portion 2230.

[0027] The lid body 220, which is based on the metal lid 2200 as described above, has a dome-shaped base portion 221 with a portion closer to the center than the outer periphery bulging upward. The base portion 221 of the lid body 220 is a doughnut plate-shaped portion with an opening serving as a viewing window in the center. The lid body 220 has a lid tubular portion 222 extending from the opening of the base portion 221 in a cylindrical shape, a lid flange portion 223 extending outward from the upper end edge of the lid tubular portion 222, a glass plate 224 abutting against the lid flange portion 223 so as to close the upper opening of the lid tubular portion 222, and an annular window frame portion 225 for sandwiching the glass plate 224 between the lid flange portion 223 and the lid flange portion 223, and the inside of the window frame portion 225 is a glass window 220w for observing the state of the storage space 10c from the outside.

[0028] The flange portion 122 of the container nozzle 120 and the protection ring 210 are laminated via a circular plate-shaped gasket S1 that is thinner than the protection ring 210 and the flange portion 122. A thin circular plate-shaped gasket S2 is also interposed between the protection ring 210 and the lid main body 220. A circular plate-shaped gasket S3 is also interposed between the lid flange portion 223 and the glass plate 224, and a circular plate-shaped gasket S4 is also interposed between the glass plate 224 and the window frame portion 225.

[0029] The metal tank 100 and the metal cover material 200 of this embodiment include a base part BP made of an iron-based metal, and a highly corrosion-resistant part HP made of a highly corrosion-resistant metal having a higher content of at least one of nickel and chromium than the iron-based metal. The highly corrosion-resistant part HP in this embodiment is made of a highly corrosion-resistant metal filled in a notch part BP1 provided in the base part BP. More specifically, the highly corrosion-resistant part HP in this embodiment is made of a highly corrosion-resistant metal welded to the base part BP at the notch part BP1.

[0030] The highly corrosion-resistant portion HP is provided so as to be exposed on the surface of the metal vat 100 or the metal lid member 200. Therefore, the surface of the metal vat 100 or the metal lid member 200 includes a base surface SB, which is the surface of the base portion BP, and a highly corrosion-resistant surface SH, which is the surface of the highly corrosion-resistant portion HP. The glass layer GL of the vat body 10 or the lid member 20 is provided so that the edge portion is located on the highly corrosion-resistant surface SH.

[0031] Glass-coated products such as glass-lined products are manufactured so that compressive stress acts on the glass layer GL. This allows the glass layer GL to exhibit high strength in glass-coated products. However, when the interface corrodes and the bonding strength between the glass layer GL and the metal product weakens, the stress distribution in the glass layer GL changes, causing excessive stress, and the glass layer GL breaks from the point where this stress occurs. The corrosion that causes such cracks progresses from the edge of the glass layer GL. As the corrosion progresses, the glass layer GL breaks into small pieces and peels off from the metal product. The peeling of the glass layer GL, called chipping, also progresses from the edge of the glass layer GL. Therefore, in metal products, the part where the edge of the glass layer GL is located is made of a highly corrosion-resistant metal, which is effective in preventing the progress of chipping.

[0032] Examples of the iron-based metal constituting the base portion BP include carbon steel and stainless steel. Examples of stainless steel include JIS SUS301, SUS301L, SUS301J1, SUS302B, SUS303, SUS304, SUS304Cu, SUS304L, SUS304N1, SUS304N2, SUS304LN, SUS304J1, SUS304J2, SUS305, SUS309S, SUS310S, SUS312L, SUS315J1, SUS315J2, SUS316, SUS316L, SUS316N, SUS316LN, SUS316Ti, SUS316J1, SUS316J1L, SUS317, SUS317L, SUS317LN, SUS317J1, SUS317J2, SUS836L, SUS890L, SUS321, SUS347, SUSXM7, SUSX Examples of the stainless steel include austenitic stainless steel such as M15J1, austenitic-ferritic stainless steel such as SUS329J1, SUS329J3L, and SUS329J4L, ferritic stainless steel such as SUS405, SUS410L, SUS429, SUS430, SUS430LX, SUS430J1L, SUS434, SUS436L, SUS436J1L, SUS443J1, SUS444, SUS445J1, SUS445J2, SUS447J1, and SUSXM27, martensitic stainless steel such as SUS403, SUS410, SUS410S, SUS420J1, SUS420J2, and SUS440A, and precipitation hardening stainless steel such as SUS630 and SUS631. The iron-based metal may be a low-carbon grade (e.g., SUS304L, SUS316L) having a carbon content of 0.030% by mass or less.

[0033] The highly corrosion-resistant metal constituting the highly corrosion-resistant portion HP preferably has a higher total content of nickel and chromium than the iron-based metal, and more preferably has a higher total content of nickel and chromium than the iron-based metal. When SUS304 (18Cr, 8Ni) or SUS304L (18Cr, 9Ni) is used as the iron-based metal, SUS316 (18Cr, 12Ni) or SUS316L (18Cr, 12Ni) may be used as the highly corrosion-resistant metal. The highly corrosion-resistant metal may be, for example, a welding material such as 308N2, 309, 309Si, 309Mo, 309L, 309LD, 309LSi, 309LMo, 309LMoD, 309LNb, 309LNbD, 310, 310S, 310L, 312, 316, 316H, 316Si, 316L, 316LSi, 316LCu, 317, 317L, 318, 318L, 320, 320LR, 329J4L, 330, 383, 385, 2209, etc., as specified in JIS Z3321. The highly corrosion-resistant metal may be a nickel-based alloy known under the trade name of Inconel or Hastelloy. The highly corrosion-resistant metal may be, for example, a corrosion-resistant and heat-resistant superalloy such as NCF600, NCF601, NCF625, NCF690, NCF718, NCF750, NCF751, NCF80A, NCF800, NCF800H, NCF825, NCF020, or NCF354 as specified in JIS G4902; or nickel or nickel-based alloys such as NW2200, NW2201, NW4400, NW4402, NW5500, NW0001, NW0665, NW0276, NW6455, NW6022, NW6210, NW6007, NW6985, or NW6002.Examples of highly corrosion-resistant metals include nickel welding materials such as Ni2061 and Ni2061J specified in JIS Z3334; nickel-copper welding materials such as Ni4060, Ni4061, and Ni5504; nickel-chromium welding materials such as Ni6072, Ni6073, Ni6076, and Ni6082; nickel-chromium-iron welding materials such as Ni6002, Ni6025, Ni6030, Ni6043, Ni6045, Ni6052, Ni6054, Ni6055, Ni6062, Ni6176, Ni6601, Ni6693, Ni6701, Ni6975, Ni6985, Ni7069, Ni7092, Ni7718, Ni8025, Ni8065, and Ni8125; The welds may be nickel-molybdenum welds such as Ni1004, Ni1008, Ni1009, Ni1024, Ni1062, Ni1066, Ni1067, and Ni1069; nickel-chromium-molybdenum welds such as Ni6012, Ni6022, Ni6035, Ni6057, Ni6058, Ni6059, Ni6200, Ni6205, Ni6276, Ni6452, Ni6455, Ni6625, Ni6650, Ni6660, Ni6686, and Ni7725; nickel-chromium-cobalt welds such as Ni6160, Ni6617, Ni7090, and Ni7263; and nickel-chromium-tungsten welds such as Ni6231.

[0034] When the highly corrosion-resistant part HP is formed by welding, it is diluted with an iron-based metal, so that the highly corrosion-resistant part HP after welding may not be made of the above-mentioned materials. Whether the corrosion resistance of the highly corrosion-resistant part HP is higher than that of the base part BP can also be determined by measuring the corrosion potential.

[0035] The base part BP and the highly corrosion-resistant part HP may be joined by a physical joining force such as screwing or shrink fitting, or may be joined by a joining material such as a welding material, or the highly corrosion-resistant metal may be used as a welding material and the welding material may be welded to the base part BP to form the highly corrosion-resistant part HP. In such a case, the welding may be fusion welding such as arc welding, gas welding, or laser welding, pressure welding such as spot welding or seam welding, or may be thermal spraying or brazing.

[0036] From the viewpoint of the robustness of the joint between the base part BP and the highly corrosion resistant part HP, the highly corrosion resistant part HP may be formed by build-up welding a highly corrosion resistant metal to the base part BP. The highly corrosion resistant part HP may be a laminate of multiple layers including a first welded layer in contact with the base part BP and a second welded layer overlapping the first welded layer. The highly corrosion resistant part HP may be welded such that beads formed by build-up welding overlap in three or more layers.

[0037] As mentioned above, the metal products used to manufacture the glass-coated products are: a) a preparation step of forming a primary member from an iron-based metal for forming the base portion BP; b) a welding step of welding a highly corrosion-resistant metal for forming the highly corrosion-resistant portion HP to the primary member to form a secondary member; c) a finishing step of machining the outer shape of the secondary part to give it a desired shape as a metal product.

[0038] In the preparation step, a primary member having a shape corresponding to the shape of the base portion BP can be formed, and a primary member 2100' having a cutout portion BP1' can be formed. In the welding step, the surface defining the cutout portion BP1' is used as the welded surface, and welding can be performed so that the cutout portion BP1' is filled with a highly corrosion-resistant metal. Since distortion or the like may occur in the primary member 2100' due to heat in the welding step, a primary member 2100' having a thickness and length that are slightly larger than those of the metal product when the cutout portion BP1' is filled with the highly corrosion-resistant metal may be used, and the entire surface of the secondary member 2100'' may be machined in the finishing step.

[0039] In the preparation step, for example, a cutting process using a lathe or the like is performed on the original member before the notch is formed, to form the notch BP1', thereby forming the primary member. More specifically, in the preparation step, a metal ring entirely made of an iron-based metal may be prepared, and the iron-based metal ring may be cut using a lathe or the like to form a notch, thereby forming the primary member. The welding step may be performed by welding a welding material to the welded surface of the primary member, and in this case, the notch BP1' may be filled with the welding material by one welding, or the notch BP1' may be filled with the welding material by multiple welding. When multiple welding steps are performed, the welding may be performed in a direction away from the welded surface. For example, when the cross-sectional shape of the notch BP1' is horizontally long, the welding may be performed so that the beads of the welding material are arranged horizontally and multiple beads are piled up in the depth direction.

[0040] In the welding process, more welding material than necessary may be welded. In the finishing process, distortion caused by welding may be corrected, or the distorted surface may be cut to be flat. In the finishing process, excess welding material may be removed by cutting.

[0041] In the preparation process, for example, taking the protection ring 210 as an example, a primary member 2100' is prepared having a recessed portion BP1' recessed from the first surface 2100a or the second surface 2100b of the metal ring 2100, as shown in Figure 3a.

[0042] 3a and 3b are provided at two locations, one on the first surface 2100a side and the other on the second surface 2100b side, and the radially outer ends of the two cutouts BP1' reach close to the outer edge of the metal ring 2100. On the other hand, the radially inner ends of the cutouts BP1' are spaced apart from the inner edge of the metal ring 2100. In other words, the cutouts BP1' are provided radially outward.

[0043] The notch portion BP1' is formed so that the cross-sectional shape of the notch portion BP1' when cut on a plane including the central axis of the metal ring 2100 is a horizontally elongated band that is long in the radial direction. The notch portion BP1' is formed so that the cross-sectional shape of the notch portion BP1' is an isosceles trapezoid that is slightly tapered from the first surface 2100a and the second surface 2100b when cut on the plane. Therefore, the notch portion BP1' is defined by three surfaces: a bottom wall surface W1 that defines the bottom surface of the notch portion BP1', and two vertical wall surfaces W2 that rise from the inner peripheral edge and the outer peripheral edge of the bottom wall surface W1.

[0044] The notch portion BP1' is provided continuously in the circumferential direction of the metal ring 2100. The bottom wall surface W1 may be formed to be parallel to the first surface 2100a or the second surface 2100b, or may not be parallel to the first surface 2100a or the second surface 2100b. The depth of the notch portion BP1' from the first surface 2100a or the second surface 2100b to the bottom wall surface W1 may be uniform or non-uniform. In this embodiment, the depth and radial dimension of the notch portion BP1' are constant in the circumferential direction of the metal ring 2100, which is the depth direction of the cross section, and the cross-sectional shape is also common in the circumferential direction. That is, the shape of the notch portion BP1' in this embodiment is a circular ring plate shape in which the thickness and radial dimension are uniform and the radial dimension is larger than the thickness.

[0045] The highly corrosion-resistant portion HP in this embodiment is formed by filling the notch portion BP1' with a highly corrosion-resistant metal by welding. Therefore, in this embodiment, the bottom wall surface W1, the inner vertical wall surface W2 (hereinafter also referred to as the "first vertical wall surface W21") rising from the inner peripheral edge of the bottom wall surface W1, and the outer vertical wall surface W2 (hereinafter also referred to as the "second vertical wall surface W22") rising from the outer peripheral edge of the bottom wall surface W1 are welded surfaces to which the highly corrosion-resistant metal is welded. In other words, the highly corrosion-resistant portion HP formed by filling the notch portion BP1' has a surface in contact with the bottom wall surface W1 and the two vertical wall surfaces W2 as a joint surface with the base portion BP. Moreover, the highly corrosion-resistant portion HP in this embodiment formed as described above has a shape corresponding to the notch portion BP1' and is an annular plate shape in which the radial dimension is larger than the thickness. That is, the highly corrosion resistant portion HP in the metal ring 2100 illustrated in FIG. 5 and the like includes a plate-like region having a horizontally elongated band-like cross section, and is constituted only by this plate-like region.

[0046] If the cutout reaches the edge of the primary member and has a vertical wall surface only on one side of the cutout, when welding is performed so that multiple beads WB are arranged side by side on the bottom wall surface, the work must be performed while being careful not to spill the welding material when the beads WB are arranged in order from the corner between the bottom wall surface and the vertical wall surface and reach the side where the vertical wall surface is not provided, which can make the work difficult, but in this embodiment, the vertical wall surface W2 is provided on both ends of the cutout, so that the welding work can be avoided while paying such attention. Also, for example, if the cutout reaches the edge of the metal ring 2100 and has a shape that is open on two sides, the first surface 2100a and the outer peripheral side surface 2100c2, the welding material will be welded so that it bulges on these two sides, but if the vertical wall surface W2 exists on both ends of the cutout and the cutout is open only on the first surface 2100a side, the welding material will bulge on only one side. Therefore, using a primary member having a notch BP1' as shown in Fig. 3b is advantageous in that the amount of welding material used to form the highly corrosion resistant portion HP can be reduced. Furthermore, the highly corrosion resistant portion HP thus formed is joined at both ends to the vertical wall surface W2 of the base portion BP, and therefore can have excellent joining strength with the base portion BP.

[0047] One or both of the first vertical wall surface W21 and the second vertical wall surface W22 may be provided so as to be perpendicular to the bottom wall surface W1, but if the corner CN where the vertical wall surface W2 and the bottom wall surface W1 intersect is recessed so as to be pointed, it becomes difficult for the highly corrosion-resistant metal to enter during welding. Therefore, the vertical wall surface W2 may be provided so as to intersect with the bottom wall surface W1 at an obtuse angle. In addition, a C-surface or an R-surface may be provided at the corner CN where the vertical wall surface W2 and the bottom wall surface W1 intersect. When the corner CN is a C-surface, the value of the corner C may be 0.5 mm or more, or may be 1.0 mm or more. When the corner CN is an R-surface, the value of the corner R may be 0.5 mm or more, or may be 1.0 mm or more. When the bottom wall surface W1 and the vertical wall surface W2 are formed at an obtuse angle, the angle may be, for example, 95 degrees or more. The angle between the bottom wall surface W1 and the vertical wall surface W2 may be 100 degrees or more, or may be 105 degrees or more. The angle between the first vertical wall surface W21 and the bottom wall surface W1 and the angle between the second vertical wall surface W22 and the bottom wall surface W1 may be the same or different. The shape (C surface, R surface, etc.) of the corner CN where the first vertical wall surface W21 and the bottom wall surface W1 intersect may be the same or different from the shape of the corner CN where the second vertical wall surface W22 and the bottom wall surface W1 intersect.

[0048] The angle between the bottom wall surface W1 and the vertical wall surface W2, and the values ​​of the corners C and R can be measured based on the cross-sectional shape when the primary member 2100' is cut on a plane along the chipping progression direction. The chipping progression direction is usually a direction perpendicular to the direction in which the edge of the glass layer GL extends, which is a radially inward direction in the protection ring 210. Therefore, when checking the angle between the bottom wall surface W1 and the vertical wall surface W2 in the protection ring 210, and the state of the corners C and R, measurements can be performed on a cross section of the protection ring 210 cut on a plane including the central axis of the protection ring 210. Note that the cross section in the direction perpendicular to the direction in which the edge GLe of the glass layer GL extends (in the case of a curved edge, the tangent direction (for example, the direction of the arrow D in FIG. 6b)) is a surface along the thickness direction of the glass layer GL, and hereinafter, the cross section is also referred to as a "thickness direction cross section TX" or the like.

[0049] The depth of the cutout portion BP1' observed in the thickness direction cross section TX (depth from the first surface 2100a to the bottom wall surface W1) may be, for example, 0.05 mm or more, 0.1 mm or more, 0.3 mm or more, or 0.5 mm or more. The depth may be, for example, 1.0 mm or more, 1.5 mm or more, 2 mm or more, or 2.5 mm or more. The depth may be, for example, 20 mm or less, 10 mm or less, 8 mm or less, or 5 mm or less. The length of the bottom wall surface W1 in the thickness direction cross section TX (the distance between the center points of the C-surface or R-surface when the corner CN is provided with the C-surface or R-surface) may be 0.8 times or more the depth of the cutout portion BP1'. The length may be 1.0 times or more, 1.2 times or more, 1.5 times or more, or 2.0 times or more the depth of the cutout portion BP1'. The length may be, for example, 5 mm or more. The length may be 8 mm or more, 10 mm or more, 15 mm or more, or 20 mm or more. The length may be, for example, 30 mm or less, 20 mm or less, or 10 mm or less.

[0050] The highly corrosion-resistant portion HP formed by filling the cutout portion BP1' with the highly corrosion-resistant metal has a cross-sectional shape that is oblong in the thickness direction from the center of the metal ring toward the edge, thereby making it possible to secure a wide highly corrosion-resistant surface SH while saving the amount of highly corrosion-resistant metal used.

[0051] The notch BP1' on the first surface 2100a side and the notch BP1' on the second surface 2100b side may have the same shape or different shapes in the thickness direction cross section TX. In this embodiment, the shape of the space in the notch BP1' is annular on both the first surface 2100a side and the second surface 2100b side. Therefore, the highly corrosion-resistant portion HP formed in this embodiment is also annular.

[0052] For example, a circular ring plate made of a highly corrosion-resistant metal may be prepared in advance to have a shape corresponding to the cutout portion BP1', and the circular ring plate may be fitted into one or both of the cutout portion BP1' on the first surface 2100a side and the cutout portion BP1' on the second surface 2100b side and fixed by spot welding or shrink fitting to form the metal ring 2100; however, in this embodiment, build-up welding is performed to provide high bonding strength between the highly corrosion-resistant portion HP and the base portion BP.

[0053] As shown in Figures 4a to 4c, build-up welding can be performed, for example, so that the beads WB are continuously formed in the circumferential direction, and can be performed so that the beads WB are arranged side by side on the bottom wall surface W1. Build-up welding can be performed so that the formation height of the beads WB is equal to or greater than the depth of the cutout portion BP1', and the beads WB do not overlap in the vertical direction. Build-up welding can be performed so that the formation height of the beads WB is less than the depth of the cutout portion BP1', and the beads WB are stacked in the vertical direction.

[0054] It is preferable to perform build-up welding so as to form a laminated structure including a first welded layer BL1 composed of one or more beads WB in contact with the bottom wall surface W1 and a second welded layer BL2 composed of one or more beads WB overlapping the first welded layer BL1 so as to be in contact with the first welded layer BL1 from the side opposite to the bottom wall surface W1. It is preferable that each of the first welded layer BL1 and the second welded layer BL2 is formed so that the multiple beads WB are arranged side by side.

[0055] The build-up welding as described above can be performed by piling up the beads WB so that they are raised higher than the first surface 2100a and the second surface 2100b, as shown in FIG. 4c.

[0056] In build-up welding, even if a bead WB is formed using a welding rod made of a highly corrosion-resistant metal, the bead WB is diluted by the iron-based metal in the area that is in direct contact with the primary component 2100' (bottom wall surface W1 and vertical wall surface W2). Therefore, by forming the above-mentioned laminated structure, the second welded layer BL2 can be made to have a higher purity than the first welded layer BL1, and the content of the iron-based metal in the second welded layer BL2 can be reduced. In addition, in this embodiment, since the highly corrosion-resistant portion HP (plate-shaped region) has a horizontally elongated cross section, the intermediate portion of the second welded layer BL2, excluding both radial ends, can be made less susceptible to dilution from the vertical wall surface W2, and the purity of the highly corrosion-resistant metal in the intermediate portion can be made high.

[0057] After the build-up welding, the excess weld material can be removed by cutting or the like to form a secondary component 2100'' as shown in Figure 5. The secondary component 2100'' may be used as the metal ring 2100 as is and a glass layer GL may be baked thereon, or it may be further treated, such as by chemical conversion treatment, to form the metal ring 2100.

[0058] The protection ring 210 is produced by a frosting process in which a green product having an unfired glass layer is produced by, for example, spraying a slurry containing glass powder onto the metal ring 2100, and a firing process in which the green product is fired in a furnace. At that time, the frosting may be performed to cover a part of the highly corrosion-resistant surface SH so that the edge of the glass layer is positioned on the highly corrosion-resistant surface SH, or may be performed to cover the entire highly corrosion-resistant surface SH so that the edge of the glass layer is positioned on the base surface SB.

[0059] The metal ring 2100 formed as described above is provided with a base surface SB, which is the surface of the base portion BP, and a highly corrosion-resistant surface SH, which is the surface of the highly corrosion-resistant portion HP. As shown in FIG. 6a, when viewed from the thickness direction of the glass layer GL to be baked, the metal ring 2100 has the base surface SB provided at the edge portion on the radially outer side, and the highly corrosion-resistant surface SH provided inside the base surface SB. As shown in FIG. 6b and FIG. 7a, the glass layer GL is baked onto the metal ring 2100 so as to cover a part or the whole of the highly corrosion-resistant surface SH. In the metal ring 2100 illustrated in the figures, the highly corrosion-resistant portion HP has a plate-shaped region PA, and the highly corrosion-resistant portion HP is composed of only the plate-shaped region PA as described above.

[0060] In the protection ring 210 of this embodiment, a glass layer GL is baked onto the first surface 2100a, the second surface 2100b, and the inner peripheral side surface 2100c1 of the metal ring 2100. The protection ring 210 is a glass-coated product in which a glass layer GL is baked onto the surface of a metal ring 2100, which is a metal product. The metal ring 2100 comprises a base portion BP made of an iron-based metal, and a highly corrosion-resistant portion HP made of a highly corrosion-resistant metal having a higher content of at least one of nickel and chromium than the iron-based metal. The surface of the metal ring 2100 is provided with a highly corrosion-resistant surface SH, which is the surface of the highly corrosion-resistant portion HP. The highly corrosion-resistant portion HP has one side which is the highly corrosion-resistant surface SH and the other side opposite the highly corrosion-resistant surface SH which is a bonding surface CF with the base portion BP. A plate-shaped region PA is provided whose cross-sectional shape when cut along a plane perpendicular to the highly corrosion-resistant surface SH is a horizontally elongated band, and the glass layer GL is baked onto the metal ring 2100 so as to cover part or all of the plate-shaped region PA.

[0061] The vertical wall surface W2 is a joint surface between the iron-based metal and the highly corrosion-resistant metal, and is nearly perpendicular to the baked surface of the glass layer GL. In such a location, the difference in the linear expansion coefficient between the iron-based metal and the highly corrosion-resistant metal may cause excessive stress in the glass layer GL after baking. In this embodiment, the plate-shaped region PA is a horizontal strip, and a certain distance or more can be secured between the first vertical wall surface W21 and the second vertical wall surface W22. Therefore, even if chipping occurs at the edge GLe of the glass layer GL, the progress of chipping can be stopped in the middle of the highly corrosion-resistant surface SH formed by the plate-shaped region PA.

[0062] As described above, the highly corrosion-resistant portion HP in this embodiment is annular plate-shaped. That is, the plate-shaped region PA extends in the circumferential direction of the protection ring 210, and the horizontally elongated cross-sectional shape is continuous not only in a cross section by one plane, but also in the depth direction (circumferential direction) of the cross section. In this embodiment, the cross-sectional shapes in all planes including the central axis of the protection ring 210 are horizontally elongated band-shaped. The plate-shaped region PA in this embodiment may be formed so that the exact same cross-sectional shape continues in the extending direction, or may be formed so that the thickness dimension, width dimension, etc. of the cross-sectional shape change in the depth direction (circumferential direction) while maintaining the cross-sectional shape as a horizontally elongated band. In glass-coated products other than the protection ring 210 illustrated in the figure, the plate-shaped region may be, for example, a polygonal frame plate shape (square frame plate shape, hexagonal frame plate shape).

[0063] In order to suppress chipping, the metal product may be formed so that most of the glass-coated surface is the highly corrosion-resistant surface SH, but it is not necessary to provide the highly corrosion-resistant portion HP over an excessively wide area. For example, the highly corrosion-resistant portion HP and its plate-shaped region PA may be provided in a disk or polygonal plate shape, but may be provided so as to extend in a strip shape along the edge of the glass layer GL in order to suppress the amount of highly corrosion-resistant metal used and reduce the labor required for welding and the like. In this case, the region whose cross-sectional shape in a plane perpendicular to the extending direction of the plate-shaped region PA is a horizontally elongated strip shape continues over the section in which the plate-shaped region PA extends, thereby suppressing the progression of chipping in the direction intersecting with the plate-shaped region PA. The plate-shaped region PA does not necessarily have to be provided over the entire section in which the edge of the glass layer GL extends, and may be provided only in a part of it. The plate-shaped region PA may be provided so as to occupy 50% or more of the length in which the edge of the glass layer GL extends, or may be provided so as to occupy 70% or more, or may be provided so as to occupy 90% or more of the length in which the edge of the glass layer GL extends. The plate-like region PA is preferably provided over the entire section (100%) of the edge portion of the glass layer GL.

[0064] Since chipping usually progresses in a direction (radial direction of the protection ring 210) perpendicular to the direction in which the edge GLe of the glass layer GL extends (direction of the arrow D in FIG. 6b), it is preferable that the highly corrosion-resistant surface SH for stopping the progress of the chipping has a certain or greater radial dimension. The radial dimension of the highly corrosion-resistant surface SH can be obtained, for example, by measuring the distance between the boundary line LL between the highly corrosion-resistant surface SH and the base surface SB in the thickness direction cross section TX. The radial dimension of the highly corrosion-resistant surface SH can be, for example, 3 mm or more. This dimension (distance between the boundary lines LL) may be 4 mm or more, 5 mm or more, 6 mm or more, 8 mm or more, or 10 mm or more. The dimension (distance between the boundary lines LL) can be, for example, 30 mm or less. It can also be 20 mm or less. The dimension (distance between the boundary lines LL) may be 15 mm or less, or 10 mm or less.

[0065] For example, as shown in FIG. 7a, the plate-shaped region PA may be formed so that at least a part of the plate-shaped region PA has a thickness of 0.05 mm or more when a virtual line segment XL perpendicular to the highly corrosion-resistant surface SH (first surface 2100a) is drawn in the thickness direction cross section TX, a first intersection point XP1 between the virtual line segment XL and the highly corrosion-resistant surface SH and a second intersection point XP2 between the virtual line segment XL and the joint surface CF (bottom wall surface W1) are obtained, and the distance between the second intersection point XP2 and the first intersection point XP1 is defined as the "thickness". The thickness of at least a part of the plate-shaped region PA may be 0.1 mm or more, 0.3 mm or more, or 0.5 mm or more. The thickness of at least a part of the plate-shaped region PA may be 1.0 mm or more, 1.5 mm or more, 2 mm or more, or 2.5 mm or more. The thickness of at least a part of the plate-shaped region PA may be 3 mm or more, or 4 mm or more. The thickness of the plate-like region PA may be, for example, 20 mm or less, or 10 mm or less. The thickness may be, for example, 8 mm or less, 6 mm or less, or 4 mm or less. The plate-like region PA may be formed such that, for example, 50% or more of the region has the above-mentioned thickness. The ratio of the region of the plate-like region PA having the above-mentioned thickness may be 60% or more, 70% or more, 80% or more, or 90% or more. The plate-like region PA may have the above-mentioned thickness in the entire region.

[0066] In this embodiment, the cross-sectional shape of the plate-like region PA in the thickness direction cross section TX is horizontally elongated. The cross-sectional shape preferably has a predetermined flatness. When the cross-sectional shape of the plate-like region PA is a horizontally elongated rectangle, the flatness can be calculated by the following formula. Flatness (%) = Short side ÷ Long side × 100% In addition, when the cross-sectional shape of the plate-shaped region PA in the thickness direction cross section TX is not rectangular and the short side and long side are not uniquely determined, the long side and short side of the rectangle having the largest area among the horizontally long rectangles that can be drawn to fit in the plate-shaped region PA can be obtained to calculate the flatness. By ensuring that the region made of highly corrosion-resistant metal in the plate-shaped region PA has such a horizontally long shape, it is possible to suppress the application of large stress to the glass layer GL. When the cross-sectional shape of the plate-shaped region PA is not rectangular and is, for example, a shape (trapezoid) as shown in FIG. 7a, the rectangle having the largest area among the horizontally long rectangles that can be drawn inside the trapezoid as shown in FIG. 7d can be obtained by obtaining the length of the short side L1 and the length of the long side L2, and the flatness (L1 / L2×100%) can be calculated.

[0067] The cross-sectional shape of the plate-like region PA is not limited to a rectangle, and may be a rounded shape as shown in FIG. 7e. In this case, the flatness can be calculated by determining the long and short sides of the rectangle with the largest area among the rectangles inscribed in the contour line that defines the plate-like region PA. In addition, if there are multiple rectangles with the largest area among the rectangles inscribed in the contour line, the flatness is calculated based on the length of the short side and the length of the long side of the rectangle with the longest side. The plate-like region PA may have a cross-sectional shape that is more rounded, or may have a shape like a horizontally long ellipse divided in half along the long side. In this case, the flatness can be calculated in the same manner as above.

[0068] The flatness is preferably 50% or less. The flatness may be 45% or less, 40% or less, 35% or less, 30% or less, or 25% or less. The flatness may be, for example, 12.5% ​​or more. The flatness may be 15% or more, or 17.5% or more.

[0069] Regarding the shape and the like of the plate-like region PA as described above, the highly corrosion-resistant portion HP on the first surface 2100a side and the highly corrosion-resistant portion HP on the second surface 2100b side may be the same or different.

[0070] The glass layer GL provided on the protection ring 210 may be a multilayer structure including an undercoat glass layer GL1 that is in direct contact with the metal ring 2100 and fired onto the metal ring 2100, and an upper glass layer GL2 that is in contact with the undercoat glass layer GL1 from the side opposite the metal ring 2100 and fired onto the metal ring 2100 via the undercoat glass layer GL1, as shown in Figure 7a, and both the undercoat glass layer GL1 and the upper glass layer GL2 may cover the entire highly corrosion-resistant surface SH, with the edge GLe located on the base surface SB.

[0071] As shown in Fig. 7b, the glass layer GL may be provided such that only the bottom glass layer GL1 entirely covers the highly corrosion-resistant surface SH, or the top glass layer GL2 has an edge positioned on the highly corrosion-resistant surface SH. As shown in Fig. 7c, the glass layer GL may be provided such that both edges of the bottom glass layer GL1 and the top glass layer GL2 are positioned on the highly corrosion-resistant surface SH.

[0072] In the embodiment shown in Fig. 7c, the edge GLe of the glass layer GL is located on the highly corrosion-resistant surface SH, so that the occurrence of chipping itself can be prevented. In order to facilitate the fulfillment of such a function, a highly corrosion-resistant portion HP as shown in Fig. 8a may be provided on the protection ring 210.

[0073] The protection ring 210 shown in Figure 8a comprises a metal ring 2100 having a base portion BP made of an iron-based metal and a highly corrosion-resistant portion HP made of a highly corrosion-resistant metal having a higher content of at least one of nickel and chromium than the iron-based metal, and the surface of the metal ring 2100 is provided with a base surface SB, which is the surface of the base portion BP, and a highly corrosion-resistant surface SH, which is the surface of the highly corrosion-resistant portion HP, and when the edge portion of the glass layer GL is viewed from the thickness direction of the glass layer GL, the highly corrosion-resistant surface SH is arranged to extend from the edge of the metal ring 2100, and the edge of the glass layer GL is located on the highly corrosion-resistant surface SH.

[0074] In the protection ring 210 shown in FIG. 8a, similarly to the protection ring shown in FIG. 7a, it is preferable that the plate-shaped region PA has a predetermined flatness (L1 / L2×100% in FIG. 8b).

[0075] As described above, in the protection ring 210 illustrated in FIG. 8a, the end of the glass layer GL, which is likely to be the starting point of chipping, is baked onto the highly corrosion-resistant surface SH, and the highly corrosion-resistant surface SH extends outward from the glass layer GL beyond the edge GLe of the glass layer GL, and reaches the edge of the metal ring 2100. The corner between the first surface 2100a and the outer peripheral side surface 2100c2 may be chamfered with R or C. Even in such a case, the range in which the glass layer GL is formed can be easily set based on the edge of the metal ring 2100 (the edge on the outer peripheral side surface 2100c2 side of the chamfered portion), making it easy to suppress chipping. If necessary, the glass layer GL may be provided so as to extend beyond the corner and wrap around the outer peripheral side surface 2100c2.

[0076] The protection ring 210 illustrated in the figure has two highly corrosion-resistant parts HP, which are separated from each other on the first surface 2100a and the second surface 2100b of the metal ring 2100. In the protection ring 210 illustrated in the figure, the two highly corrosion-resistant parts HP are laminated on the base part BP in the thickness direction cross section TX, and the highly corrosion-resistant parts HP have a joint surface CF with the base part BP, which is the opposite surface to the highly corrosion-resistant surface SH. It is also possible to form the highly corrosion-resistant parts HP to the same thickness as the metal ring 2100 and form the highly corrosion-resistant surfaces SH on the two surfaces, the first surface 2100a and the second surface 2100b, with one highly corrosion-resistant part HP, but by doing as described above, the amount of highly corrosion-resistant metal used can be reduced.

[0077] 8a includes a first surface 210a facing the lower surface of the lid body 220, a second surface 210b opposite the first surface 210a facing the flange portion 122 of the container nozzle 120, an inner peripheral side surface 210c1 connecting the inner peripheral edge of the first surface 210a and the inner peripheral edge of the second surface 210b, and an outer peripheral side surface 210c2 connecting the outer peripheral edge of the first surface 210a and the outer peripheral edge of the second surface 210b, in which the metal ring 2100 is exposed without being covered by the glass layer GL on the outer peripheral side surface 210c2. Also, at both ends of the protection ring 210 in the axial direction, the outer peripheral side surface 210c2 is a highly corrosion-resistant surface SH, but the intermediate portion is a base surface SB.

[0078] In order to prevent the base surface SB from rusting due to liquid adhering to the underside of the lid body 220 when the lid is opened or closed, the protection ring 210 may have the entire outer circumferential side surface 210c2 as a highly corrosion-resistant surface SH, as shown in Fig. 9. That is, the highly corrosion-resistant surface SH of the metal ring 2100 may be provided so as to extend beyond the corner between the first surface 2100a and the outer circumferential side surface 2100c2 to the corner between the outer circumferential side surface 2100c2 and the second surface 2100b.

[0079] In the protection ring 210 illustrated in Figure 9, the portion made of a highly corrosion-resistant metal includes a first plate-shaped region PA (first plate-shaped region PA1) that constitutes the highly corrosion-resistant surface SH on the first surface 2100a, a second plate-shaped region PA (second plate-shaped region PA2) that constitutes the highly corrosion-resistant surface SH on the second surface 2100b, and a connection portion PAC that connects the first plate-shaped region PA (first plate-shaped region PA1) that constitutes the highly corrosion-resistant surface SH on the second surface 2100b in the vertical direction at the radially outer edge portion of the metal ring 2100 to constitute the highly corrosion-resistant surface SH on the outer peripheral side surface 2100c2, and they are joined so as to form a U-shaped cross section.

[0080] In such an embodiment, all exposed surfaces of the metal ring 2100 become highly corrosion-resistant surfaces SH, so that the protection ring 210 can exhibit excellent corrosion resistance.

[0081] The container nozzle 120 may have a similar configuration to the protection ring 210, as shown in Fig. 10. That is, in the container nozzle 120, a notch is provided in the flange portion 1220 of the metal nozzle 1200 serving as the base, and a highly corrosion-resistant portion HP having a plate-shaped region PA is formed by filling the notch with a highly corrosion-resistant metal, and a highly corrosion-resistant surface SH and a base surface SB are provided on the upper surface of the flange portion 1220, and a glass layer GL is baked to cover a part or all of the plate-shaped region PA constituting the highly corrosion-resistant surface SH. In the container nozzle 120, the glass layer GL is baked on the plate-shaped region PA having a horizontally elongated belt-like shape in a cross section in the thickness direction, thereby preventing chipping from progressing.

[0082] The container nozzle 120 and the like may also adopt a spigot structure as shown in FIG. 11a. In the container nozzle 120 illustrated in FIG. 11a, the highly corrosion-resistant portion HP has a step, and the highly corrosion-resistant surface SH is provided with a low-step region SHL on the lower step side of the step, a high-step region SHH on the higher step side of the step, and a connection region SHC connecting the low-step region SHL and the high-step region SHH, and the glass layer GL is baked to the low-step region SHL, and the edge portion of the glass layer GL is baked to the connection region SHC. In this embodiment, the occurrence of chipping can be suppressed. Such a spigot structure can also be adopted in the protection ring 210 and other glass-coated products.

[0083] In the container nozzle 120 as shown in FIG. 11a, similarly to the protection ring, it is preferable that the plate-shaped area PA has a predetermined flatness (L1 / L2×100% in FIG. 11b).

[0084] In the above, the protection ring 210 and the metal cover flange portion 2230 are exemplified as having a circular shape in plan view, but the above-mentioned effects are also exhibited for those having a square shape in plan view or a polygonal shape other than a square. In addition, the above-mentioned effects are also exhibited for general-purpose enamel products other than glass-lined products. In addition, the above-mentioned effects are exhibited not only for enamel products but also for other glass-coated products.

[0085] As described above, this specification includes the following disclosures.

[0086] (1) A glass-coated product in which a glass layer is baked onto the surface of a metal product, The metal product comprises a base portion made of an iron-based metal, and a highly corrosion-resistant portion made of a highly corrosion-resistant metal having a higher content of at least one of nickel and chromium than the iron-based metal, A highly corrosion-resistant surface, which is a surface of the highly corrosion-resistant portion, is provided on a surface of the metal product, The highly corrosion resistant portion includes: a plate-like region is provided, the plate-like region having a highly corrosion-resistant surface on one side and a joint surface with the base portion on the other side opposite the highly corrosion-resistant surface, the plate-like region having a cross section that is a horizontally elongated band shape when cut along a plane perpendicular to the highly corrosion-resistant surface; A glass-coated product, wherein the glass layer is baked onto the metal product so as to cover a part or all of the plate-like region.

[0087] (2) The glass-coated product according to (1), wherein the highly corrosion-resistant portion is joined to the base portion at both ends in at least one direction along the highly corrosion-resistant surface.

[0088] (3) The glass-coated product according to (1) or (2), wherein the flatness of the plate-like region in the cross section is 12.5% ​​or more and 50% or less.

[0089] (4) The glass-coated product according to any one of (1) to (3), which is a glass-lined product.

[0090] The present invention is not limited to the above examples and various modifications can be made. [Explanation of symbols]

[0091] 1: Reactor, 10: tank body, 10c: storage space, 100: Metal tank, 110: main body, 111: trunk, 112: bottom, 113: ceiling, 120: container nozzle, 121: cylindrical portion, 122: flange portion, 1100: metal tank body, 1110: body, 1110c: central axis, 1120: bottom, 1130: ceiling, 1200: metal nozzle, 1210: cylindrical portion, 1220: flange portion, 1220a: first surface, 1220b: second surface, 1220c: side surface, 20: Lid member, 200: Metal lid material, 210: protection ring, 210c1: inner peripheral side surface, 210c2: outer peripheral side surface, 220: lid body, 220w: glass window, 221: base plate, 222: lid cylindrical part, 223: lid flange part, 224: glass plate, 225: window frame part, 2100: metal ring, 2100': primary member, 2100": secondary member, 2100a: first surface, 2100b: second surface, 2100c1: inner peripheral side surface, 2100c2: outer peripheral side surface, 2200: gold cover, 2210: base plate, 2220: gold cover cylindrical part, 2230: gold cover flange part, BP: base portion, BP1: notch portion, BP1': notch portion, CN: Corner, CF: joint surface, GL: glass layer, GL1: bottom glass layer, GL2: top glass layer, GLe: edge, HP: High corrosion resistance part, LL: Boundary line, PA: Plate-like region; S1: Gasket, S2: Gasket, S3: Gasket, S4: Gasket, SB: Base surface, SH: Highly corrosion resistant surface, SHC: Connection region, SHH: High-level region, SHL: Low-level region, W1: Bottom wall, W2: Vertical wall surface, W21: First vertical wall surface, W22: Second vertical wall surface, WB:Bead

Claims

1. A glass-coated product in which a glass layer is baked onto the surface of a metal product, The metal product comprises a base portion made of an iron-based metal, and a highly corrosion-resistant portion made of a highly corrosion-resistant metal having a higher content of at least one of nickel and chromium than the iron-based metal, A highly corrosion-resistant surface, which is a surface of the highly corrosion-resistant portion, is provided on a surface of the metal product, The highly corrosion resistant portion includes: a plate-like region is provided, the plate-like region having a highly corrosion-resistant surface on one side and a joint surface with the base portion on the other side opposite the highly corrosion-resistant surface, the plate-like region having a cross section that is a horizontally elongated band shape when cut along a plane perpendicular to the highly corrosion-resistant surface; A glass-coated product, wherein the glass layer is baked onto the metal product so as to cover a part or all of the plate-like region.

2. 2. The glass-coated product according to claim 1, wherein said highly corrosion-resistant portion is joined to said base portion at both ends in at least one direction along said highly corrosion-resistant surface.

3. 2. The glass-coated product according to claim 1, wherein the flatness of the plate-like region in the cross section is 12.5% ​​or more and 50% or less.

4. 4. The glass-coated product according to claim 1, which is a glass-lined product.

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