JP2004298432A - Cooking ware in which stain can be easily removed, and exterior surface of cooking equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cooking ware coping with a stainless product or a magnetic cooker having strong hardness on the front surface. <P>SOLUTION: The cooking ware is molded with austenitic stainless steel or a low carbon ferrite system stainless steel member. The front surface of the cooking ware is hardened by a diffusion treatment intrinsic to carbon, and polished. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Field of the Invention]
The present invention relates to a metal cooking utensil used for cooking and an exterior material constituting an exterior surface of the cooking equipment. The cooking utensil mainly includes a pan, a pot, a kettle, a pot, a frying pan, and the like. It is used for gas fire, electric heating, etc., and the outer surface of the cooking equipment includes an upper plate and a door surface of a sink, an upper plate of a gas stove, an electric stove, a magnetic cooker and the like. These are things that are exposed to burns, oil stains, and scratches during cooking, and also those that must be kept clean at all times for aesthetic and hygienic reasons.
[0002]
[Prior art]
Conventional metal cooking utensils include those using aluminum or stainless steel. Some aluminum alloys are anodized to harden the surface. Some of those using stainless steel have their surfaces anodized for aesthetic reasons. In addition, there are those having a surface treated with a fluororesin, and those having an enamel finish to which glass or the like is adhered. The anodized surface has low hardness and is weak against impacts due to the softness of the base material. The hardness of the anodic oxide film is a hardness that is slightly harder than that of the base material. A surface treated with a fluororesin is highly effective in preventing scorching and the like. However, if the surface is accidentally scorched at a high temperature, for example, the fluororesin will be altered or burnt. In addition, it cannot be used on the surface of a high-temperature portion that is subject to fire. Enamel-finished ones have a hard surface and are hardly stained, but are vulnerable to impacts and cracks are easily formed, so they require careful handling. The act of rubbing with a scourer or the like to reduce burning such as burning and spilling of cooking utensils on fire is repeated daily. As the exterior surface material of the cooking equipment, there are resin materials, stainless steel and enamel finishes. The resin material has a soft surface and is easily scratched. Stainless steel is generally not subjected to a surface hardening treatment. In addition, the enamel finish has hardness but is weak against impact. For example, in a cooking sink, a cutting board, a kitchen knife or the like is used, and a setware bowl or the like is placed thereon, so that the situation is apt to be scratched. Those having a low surface hardness were easily damaged, and those having a high hardness enamel finish had a weakness against impact.
[0003]
In addition, there has been a type of austenitic stainless steel used as a material for cutlery such as screws, spoons, and forks, and carbon has been inherently diffused by carbon intrinsic diffusion treatment to obtain high hardness, but cooking utensils and pots belonging to these have been obtained. There were none used for the exterior surface materials of pots, kettles, kettles, pots, frying pans, etc., and the exterior surfaces of cooking facilities and the associated kitchen sinks, gas and electric stoves, magnetic cookers, freezers, refrigerators, etc. . In addition, there were no magnetic induction type cooking utensils and those corresponding to pots, kettles, kettles, frying pans, etc. belonging thereto.
[0004]
In addition, none of low carbon ferritic stainless steels or stabilized stainless steels to which titanium, niobium, zirconium, molybdenum or a combination thereof were added in a small amount to obtain a high hardness by carbon-specific diffusion treatment. Further, there was no magnetic material effective for an electromagnetic cooker, which obtained a high hardness by performing a carbon-specific diffusion treatment.
[0005]
[Problem to be solved]
Conventional metal cooking utensils may be rubbed with scourers or the like to remove scorched sticks and the like. In addition, even ordinary dirt may be washed with a detergent containing an abrasive or the like, so that it is always in a fragile condition. In addition, the exterior surface of the cooking equipment is easily damaged by rubbing with other utensils or the action of removing dirt. In addition, if dirt adheres to the wound, it becomes difficult to remove the dirt, and if it is rubbed to remove the dirt, it is easy to fall into a vicious circle of saying that it will cause additional damage. If the hardness of the surface of the mother body is high, the mother body is hardly damaged even when dirt is removed. For this reason, the hardness of the exterior surface material of the metal cooking utensil and the cooking equipment is increased, the surface is hardly damaged, the cleaning property is improved, the sanitation is improved, and the aesthetic appearance is also maintained.
[0006]
[Means for Solving the Problems]
The present invention according to claim 1 is a cooking utensil or a cooking tool made of austenitic stainless steel, low carbon ferritic stainless steel, or stabilized stainless steel to which a small amount of titanium, niobium, zirconium, molybdenum or a combination thereof is added. In the exterior surface material of the equipment, carbon is intrinsically diffused to the surface by carbon intrinsic diffusion treatment, and the surface is polished.
[0007]
According to a second aspect of the present invention, in the first aspect, the cooking utensil is a pot, a kettle, a kettle, a pot, or a frying pan including an electromagnetic induction type.
[0008]
According to a third aspect of the present invention, in the second aspect, the shape of the cooking utensil is such that at least the bottom surface of the main body is substantially flat and the side surfaces are substantially hemispherical or conical, and two thirds or more are overlapped when they are overlapped. It is.
[0009]
According to a fourth aspect of the present invention, in the first aspect, the exterior surface material of the cooking equipment is a cooking sink, a stove, a magnetic cooker, a freezer, and a refrigerator.
[0010]
The present invention according to claims 1 to 4 above is an austenitic stainless steel whose surface is hardened by intrinsically diffusing carbon by carbon intrinsic diffusion treatment. In the conventional carburizing technique, carbon is bonded to a metal crystal to form a surface as a compound (a cementite structure or the like), so that it is brittle, and rust easily occurs due to precipitation of carbon and the like. On the other hand, the carbon-specific diffusion process is a process in which carbon enters into the gaps between crystals, there is almost no elution of carbon, and the process is excellent in wear resistance and the like. In the case of stainless steel SUS316L, the hardness (HV: 50 g load) was higher than that of the surface, and a hardness of about 10 μm was obtained at around 900. Even with stainless steel SUS304, which is inexpensive, a HV hardness of around 900 was obtained before surface polishing. As a result, an HV hardness of 600 or more was obtained even after surface polishing. It can be said that the hardness of the martensitic stainless steel is considerably higher than that of the HV hardness of about 300 to about 400. Further, the hardness gradually decreases from 20 μm to around 50 μm from the surface. The surface has a high hardness and the inside has a low hardness HV of 200 or less, and exhibits the properties of an austenitic stainless steel.
[0011]
Further, the surface is hardened by inherently diffusing carbon into low carbon ferritic stainless steel by an intrinsic carbon diffusion treatment. Conventionally, it has been said that performing carbon-specific diffusion treatment on ferritic stainless steel has no effect. However, low carbon ferritic stainless steel (eg, NAR-160 steel type of Sumitomo Metal Industries, carbon content 0.015 wt% niobium) ) (Hardness: HV: load of 50 g), a hardness around 500 was obtained. In addition, by polishing the surface, it becomes an outer material of cooking utensils and cooking equipment with increased brightness, is less likely to rust, is less likely to be damaged as a whole, and can maintain its beauty forever. Shows excellent properties in abrasion resistance. Further, low-carbon ferritic stainless steel has a magnetic material and exhibits properties that are effective for an electromagnetic cooker and also has excellent workability.
[0012]
Further, the surface is hardened by intrinsically diffusing carbon by a carbon intrinsic diffusion treatment in a stabilized stainless steel to which titanium, niobium, zirconium, molybdenum or a combination thereof is added in a small amount.
[0013]
Intergranular corrosion is mainly observed in austenitic stainless steels. When cooling below the annealing temperature, when the required cooling rate cannot be obtained, or when the quenched product is reheated to a temperature range of about 500 to 800 ° C, the grain boundary corrosion occurs. It is a phenomenon that becomes extremely susceptible to corrosion. This is considered to cause severe corrosion since Cr carbide Cr23C6 precipitates at the crystal grain boundaries and the concentration of Cr in the vicinity thereof decreases. On the other hand, the stabilized stainless steel is an austenitic stainless steel in which a small amount of titanium, niobium, zirconium, molybdenum, or a combination thereof is added, and deterioration of corrosion resistance due to precipitation of chromium carbide is improved. Similarly, a low-carbon ferritic stainless steel (eg, a steel type NAR-160 from Sumitomo Metal Industries, a stainless steel containing 0.015 wt% niobium) contains a small amount of titanium, niobium, zirconium, molybdenum or a combination thereof. However, it can be said that the stainless steel is a stabilized stainless steel in which deterioration of corrosion resistance due to precipitation of chromium carbide is improved.
[0014]
On the other hand, the carbon-specific diffusion treatment is a treatment in which the passivation film of stainless steel, O (oxide film) is replaced with F (fluoride film) and activated, and then C (carbon) is diffused solidly into the gaps of the surface crystal lattice. Generally, after the base material is inserted into the furnace, the temperature is raised to about 500 ° C., a fluorine-based gas is blown, and after the fluorine-based gas is discharged, a carburizing-based gas is blown, and the carburizing is performed at about 500 ° C. for 10 hours or more. It is. For this reason, the carbide of Cr precipitates at the crystal grain boundaries in the stainless steel, which may promote intergranular corrosion, and it is considered that such a tendency occurs partially even at 500 ° C. or less.
[0015]
From these facts, the use of stabilized stainless steel reduces the precipitation of Cr carbide at the crystal grain boundaries, increases the range of temperature rise in the carbon-specific diffusion treatment, and increases the carburization coefficient of the specific diffusion. It is possible to shorten the time and release the temperature control that is conscious of the intergranular corrosion temperature, which enables inexpensive processing.
The purpose of the present invention is to mainly use the surface hardness by the carbon-specific diffusion treatment for the exterior surface materials of cooking utensils and cooking equipment, and the scope of the claims is not determined by the difference in hardness due to treatment or post-processing. In order to reduce scratches due to contact with conventional stainless steel products and to make it hard to be damaged by scrubbing such as scourers, if the hardness is higher than stainless steel base metal (about twice or more than that of base metal) Good thing.
[0016]
The carbon-specific diffusion treatment does not show the effect of surface hardening on martensitic stainless steel containing a large amount of carbon. In general, stainless steel SUS304 is partially transformed during cold working to form martensite. Therefore, avoid work that easily causes work hardening, or use stainless steel such as SUS316L, etc., which is low carbon and contains molybdenum. It is effective to use the material. However, there was no noticeable difference in the hardness of the stainless steel SUS304 due to the cold working in the processing of a general pot or the like. Since SUS304 is cheaper than SUS316L or the like, it can be considered to be effectively used. The carbon inherently diffused by the carbon inherent diffusion treatment is less likely to crack, peel, and rust even when bent, as compared with the conventional nitriding treatment. A black film adheres to the surface of the stainless steel after the carbon-specific diffusion treatment. Since the black film has a characteristic of being relatively easily rusted, a method of removing it by electrolytic treatment is generally adopted. As the surface polishing, electrolytic polishing, barrel polishing, or the like, and a combination thereof are employed. Here, the method for removing the black film and the method for polishing the surface are not specified. Further, the black film here has a higher hardness than the original base material and also has an aesthetic appearance, so that the black film may be in an adhered state unless a use condition requiring particularly high corrosion resistance is required. Further, the corrosion resistance in the state where the black coating is adhered is improved by using a stabilized stainless steel (hereinafter, referred to as a stabilized stainless steel) in which a small amount of titanium, niobium, zirconium, molybdenum or a combination thereof is added to the base material. .
[0017]
【Example】
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a perspective view of a cooking utensil according to an embodiment of the present invention. A cooking utensil 1 includes a cooking utensil main body 2 having a processed surface 6 subjected to a carbon-specific diffusion treatment and polished surface, and a lid 4. A lid knob 5 is attached, and a handle 3 is attached to the cooking utensil main body 2. The cooking utensil body 2 is formed of austenitic stainless steel, low-carbon ferritic stainless steel, or stabilized stainless steel and a three-layer clad material in which aluminum is bonded inside.
[0018]
When the low-carbon ferritic stainless steel is used, for example, the clad material is a magnetic material, and thus can be an electromagnetic induction type cooking utensil. The clad material may be a combination of an austenitic stainless steel on the outer surface and a low carbon ferrite stainless steel on the inner surface. The clad material may have three or five layers, and the surface may be austenitic stainless steel, low-carbon ferrite stainless steel, or stabilized stainless steel.
[0019]
FIG. 2 is a plan view of a cooking utensil according to another embodiment of the present invention. The cooking utensil 1 is formed of austenitic stainless steel, low-carbon ferritic stainless steel, or stabilized stainless steel, and then subjected to carbon-specific diffusion treatment. The cooking utensil main body 2 includes a processed surface 6 that has been applied and polished, and a lid 4, and a lid knob 5 is attached to the lid 4. The cooking utensil main body 2 is formed of austenitic stainless steel, and shows a state in which a magnetic body 12 such as ferritic stainless steel is adhered to the inside.
[0020]
FIG. 3 is a perspective view of another embodiment of the present invention, in which the cooking utensil 1 is formed of austenitic stainless steel, low-carbon ferritic stainless steel, or stabilized stainless steel, and then subjected to a carbon-specific diffusion treatment and polished surface. 6 shows a cooking utensil main body 2b and a handle portion 3a. The cooking utensil main body 2b is subjected to carbon-specific diffusion treatment and surface polishing, and then the handle portion 3a is attached with rivets or the like.
[0021]
FIG. 4 is a perspective view of another embodiment of the present invention. The cooking utensil 1 is formed of austenitic stainless steel, low-carbon ferritic stainless steel, or stabilized stainless steel, and then subjected to a carbon-specific diffusion treatment and polished. The cooking utensil main body 2b is composed of the processing surface 6 and the handle portion 3b. The cooking utensil main body 2b is composed of the handle coupling portion 13, and the cooking utensil main body 2b and the handle portion 3b are easily detachable. Shows the state where it was removed. The cooking utensil main body 2b may be subjected to a carbon-specific diffusion treatment and then surface polishing after joining the handle coupling portion 13, or may be subjected to a carbon-specific diffusion treatment and surface polishing and then joined.
[0022]
FIG. 5 shows a plan view of another embodiment of the present invention, showing a state in which the cooking utensil main body 2a is overlaid. FIG. 5A shows a cooking utensil body 2a having a substantially flat bottom surface and a substantially hemispherical side surface, and shows a height portion 7 and an overlapping portion 8 when the cooking utensils 2a are overlapped. The cooking utensil body 2a is a cooking utensil having a structure formed by attaching the handle 3.
[0023]
In general, the carbon-specific diffusion treatment is carried out by inserting the base material in the furnace, raising the temperature to around 500 ° C., blowing in a fluorine-based gas, discharging the fluorine-based gas, and then injecting a carburizing-based gas and keeping the temperature at around 500 ° C. for 10 hours or more. This is the process of performing In the case of SUS-304 or low carbon ferritic stainless steel, it takes about 20 hours. For this reason, how much base material can be put in the furnace affects the price. In particular, pots and kettles tend to occupy space in the furnace, and therefore are required to have a shape that can be overlapped as efficiently as possible. By calculation from the general muffle furnace and the general pan size, it was determined that at least the overlapping portion 8 was required to be at least two-thirds of the height portion 7.
[0024]
FIG. 5B shows a state in which the cooking utensil bodies 2a having substantially flat bottom surfaces and substantially hemispherical side surfaces are superimposed, and shows a cooking utensil having a structure formed by only the cooking utensil main body 2a. FIG. 5C shows a cooking utensil body 2a having a substantially flat bottom surface and a conical side surface, and shows a state in which the cooking utensils 2a are overlapped. Further, the cooking utensil main body 2a is a cooking utensil having a structure in which a handle portion is integrally formed.
[0025]
FIG. 6 shows another embodiment of the present invention, in which (a) shows a front view and (b) shows a side view. The cooking utensil 1 is a cooking utensil having a structure integrally formed with the cooking utensil main body 2a and the handle 3c. Also, a heat dispersing hole 9 is provided near the handle portion 3c so that the handle is unlikely to be heated by heat conduction. Further, the cooking utensil of this embodiment can be used as a salad bowl or a serving dish.
[0026]
FIG. 7 shows a perspective view of another embodiment of the present invention, in which a cooking facility 10 has an outer surface 11b of a cooking table and an outer surface 11a of a gas stove, and an outer surface 11b of a door. Alternatively, it is formed of a low carbon ferrite stainless steel or a stabilized stainless steel, and is formed of an exterior surface composed of a processed surface 6 which is subjected to a carbon-specific diffusion treatment and polished. Although not shown, the exterior surface of the cooking equipment here may be a cooking sink, gas stove, electric stove, magnetic cooker, freezer, refrigerator, or the like.
[0027]
【The invention's effect】
The present invention provides a clean and hygienic exterior surface of a cooking utensil or a cooking facility with an aesthetic appearance, as described above, and has the effect of lasting beautifully and without damage, and in the case of replacement by purchase. The frequency of replacement is greatly improved, and it can also contribute to environmental conservation. In addition, pots and pots used as cooking utensils are also used only in the kitchen because they retain their aesthetic appearance.However, they can also be used on serving tables as serving plates and salad balls. It can be said that the invention is an extremely useful invention in which the range of use is expanded in addition to the function as a cooking appliance, and a new design shape appears.
[0028]
[Brief description of the drawings]
FIG. 1 is a perspective view of an embodiment of a cooking utensil according to the present invention.
FIG. 2 is a front view of another embodiment of the cooking utensil of the present invention.
FIG. 3 is a perspective view of another embodiment of the cooking utensil of the present invention.
FIG. 4 is a perspective view of another embodiment of the cooking utensil of the present invention.
FIG. 5 is a front view of another embodiment of the cooking utensil of the present invention.
FIG. 6 is a front view and a side view of another embodiment of the cooking utensil of the present invention.
FIG. 7 is a perspective view of another cooking equipment embodiment of the present invention.
[0029]
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Cookware 2 ... Cookware body 2a ... Cookware body 2b ... Cookware body 3 ... Handle part 3a ... Handle part 3b ... Handle part 3c ... Handle part 4 ... Lid 5 ... Lid knob part 6 ... Processing surface 7 ... High Depth part 8 Overlapping part 9 Heat dispersing hole 10 Cooking equipment 11 Exterior surface 11 a Exterior surface 11 b Exterior surface 12 Magnetic body 13 Attachment joint

Claims (4)

For exterior surfaces of cooking utensils and cooking equipment made of austenitic stainless steel, low-carbon ferritic stainless steel, or stabilized stainless steel containing a small amount of titanium, niobium, zirconium, molybdenum or a combination thereof The surface is polished by intrinsic diffusion hardening of carbon by carbon intrinsic diffusion treatment on the surface. The cooking utensil according to claim 1, wherein the cooking utensil is a pot, a kettle, a kettle, a pot or a frying pan including an electromagnetic induction type. 3. The cooking utensil according to claim 2, wherein at least the bottom surface of the main body is substantially flat and the side surface is substantially hemispherical or conical and at least two-thirds overlap when they are overlapped. 2. The cooking equipment according to claim 1, wherein the exterior surface material of the cooking equipment is a cooking sink, a stove, a magnetic cooker, a freezer, and a refrigerator.

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