Method for manufacturing cookware and cookware

Abstract

The invention provides a method for manufacturing cookware and the cookware. The manufacturing method of the cookware comprises the steps that a thermal spraying layer is formed on a cookware base body through a ceramic material; the surface layer of the thermal spraying layer is subjected to remelting treatment, so that the cookware is manufactured, the remelting area serves as the surface layer of the cookware, and the ceramic material comprises at least one of ferroferric oxide, iron nitride, iron carbide and iron carbonitride. According to the method for manufacturing the cookware provided by the embodiment of the invention, the cookware with better corrosion resistance can be manufactured.

Description

Technical Field

[0001] The present application relates to the field of cookware, and in particular, to a method for manufacturing a cookware and the cookware. Background Art

[0002] In the cookware manufacturing industry, in order to achieve corrosion resistance and wear resistance (high hardness) of the product, chemical nitriding treatment is usually performed on the surface of the substrate to form an iron nitride film, high-temperature heat treatment is performed on the iron substrate to form a ferroferric oxide film on its surface, or the coating surface of the cookware is sealed.

[0003] Specifically, chemical nitriding usually involves placing the substrate in a nitrogen-containing environment at 550°C-600°C for more than 5 hours. In this way, a dense layer with a thickness of 10μm-20μm and a hardness of about 1000HV can be formed, thereby obtaining a corrosion-resistant coating. However, this method has disadvantages such as high energy consumption and low efficiency. The iron substrate is subjected to high-temperature heat treatment to form a ferroferric oxide film layer, specifically by using a flame above 1000°C to chemically convert iron atoms and oxygen on the surface of the substrate to form a ferroferric oxide film layer. Although this film layer has a certain degree of corrosion resistance, the thickness of the film layer is limited, usually less than 5μm, so the corrosion resistance is average and the product is still prone to rust. In addition, the coating surface of the cookware is sealed to give it a certain degree of corrosion resistance, but the sealing operation usually uses an organic sealant, which is less safe and the sealant is easily detached during use, resulting in insufficient corrosion resistance.

[0004] In view of this, it is urgent to develop a new method for manufacturing corrosion-resistant cookware. Summary of the Invention

[0005] Therefore, the purpose of this application is to provide a method for manufacturing cookware and cookware, so as to develop a new way to manufacture corrosion-resistant cookware and solve the corrosion resistance problem of cookware.

[0006] According to a first aspect of the present application, a method for manufacturing a cookware is provided, wherein the method for manufacturing the cookware comprises:

[0007] forming a thermal spray coating by thermally spraying ceramic material on a cookware substrate;

[0008] Remelting the surface layer of the thermal spray coating to form a remelted region, thereby manufacturing a cookware, wherein the remelted region serves as the surface layer of the cookware;

[0009] Wherein, the ceramic material includes at least one of ferroferric oxide, iron nitride, iron carbide and iron carbide nitride.

[0010] According to the method for manufacturing cookware provided in an embodiment of the present application, a thermal spray coating is formed by thermal spraying a specific ceramic material, and then the surface of the thermal spray coating is remelted to form the surface of the thermal spray coating into a remelted area, wherein the remelted area itself has improved surface hardness, smaller internal pores and good surface properties, etc., so using it as a contact surface with cooked food can better resist erosion by corrosive media, has good corrosion resistance, and can extend the corrosion resistance life of the coating.

[0011] In some embodiments, the remelting process uses an electron beam remelting process.

[0012] In these embodiments, by performing pulsed electron beam treatment on a thermal spray coating formed of ferrosoferric oxide, iron nitride, iron carbide, or iron carbide nitride, a remelted region with improved surface properties and enhanced bonding strength can be formed, thereby improving the corrosion resistance of the overall coating. Furthermore, during the pulsed electron beam treatment, the energy of the pulsed electron beam can be controlled to ensure that only the surface layer of the thermal spray coating is treated without affecting the substrate.

[0013] In some embodiments, the parameters of the electron beam remelting process include:

[0014] The electron beam power is 25Kev-35Kev; the energy density is 3J·cm 2 -6J·cm 2 ; Pulse duration is 1μS-3μS; vacuum degree is 1×10 -3 Pa-2×10 -3 Pa; electron beam spot size 50mm-80mm.

[0015] In these embodiments, under the above parameters, the pulsed electron beam can process the surface layer of the thermal spray coating at a suitable temperature for a certain period of time, thereby facilitating the formation of a remelted layer with good performance and avoiding excessive remelting and impact on the substrate.

[0016] In some embodiments, remelting the surface layer of the thermal spray coating includes:

[0017] Electron beam remelting is performed multiple times on the surface layer of the thermal spray coating.

[0018] In these embodiments, performing electron beam remelting on the surface layer of the thermal spray coating for an appropriate number of times can enhance the density of the surface layer and improve the grain refinement and adhesion of the surface layer.

[0019] In some embodiments, the method of manufacturing a cookware does not include the step of sanding the remelted area and / or the thermal sprayed layer.

[0020] In these embodiments, the method for manufacturing the cookware does not include the step of sanding the remelted area and / or the thermal sprayed layer, thereby simplifying the cookware manufacturing process.

[0021] In some embodiments, the thermal spray coating has a thickness of 30 μm-60 μm.

[0022] In these embodiments, the thermal spray coating can have a thickness of 30 μm to 60 μm, which can, to a certain extent, avoid the risk of detachment due to high thermal stress caused by thick coating. If the thickness of the thermal spray coating is less than 30 μm, the coating will not form a film easily and will not be able to completely cover the cookware substrate. If the thickness of the thermal spray coating is greater than 60 μm, the coating will experience high thermal stress and be prone to collapse. In some embodiments, the remelting region is formed in an area corresponding to 15 μm to 25 μm inward from the surface of the thermal spray coating.

[0023] In these embodiments, if the thickness of the remelted area is greater than 25 μm, a higher temperature and a longer time are required, which may cause the ceramic layer to be overheated, resulting in overall cracking or falling off, a decrease in the strength of the remelted area, and a risk of damage to the substrate (for example, the aluminum substrate melts and deforms, the outer surface of the stainless steel substrate is severely rusted due to oxidation, etc.); if the thickness of the remelted area is less than 15 μm, the rough surface formed by thermal spraying cannot be completely flattened, resulting in the final density and roughness of the pot surface being too high, poor long-term corrosion resistance, and affecting subsequent use.

[0024] In some embodiments, the cookware substrate includes any one of an aluminum substrate, an iron substrate, a magnesium substrate, a copper alloy substrate, an alumina substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed by the above substrates.

[0025] In these embodiments, the above manufacturing method can be applied to various types of cookware bases, and the bases have a wider range of applications.

[0026] According to a second aspect of the present application, a cookware is provided, wherein the cookware includes a cookware base and a corrosion-resistant coating formed on the surface of the cookware base, the corrosion-resistant coating is formed of at least one of ferroferric oxide, iron nitride, iron carbide and nitride iron carbide, the corrosion-resistant coating includes a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area, and the remelting area serves as the surface layer of the cookware.

[0027] According to the cookware provided in the embodiment of the present application, the corrosion-resistant coating of the cookware is formed by at least one of ferroferric oxide, iron nitride, iron carbide and nitride iron carbide. Due to the inherent characteristics of the forming material, the corrosion-resistant coating itself has a certain corrosion resistance. The corrosion-resistant coating includes a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area, that is, the corrosion-resistant coating includes a thermal spraying area inside the corrosion-resistant coating and a remelting area connected to the outside of the thermal spraying area and on the surface of the corrosion-resistant coating. The remelting area itself has improved surface hardness, smaller internal pores and good surface properties. Therefore, using it as the surface layer of the corrosion-resistant coating can better resist erosion by corrosive media, has good corrosion resistance, and can extend the corrosion life of the coating. The remelting area is located outside the thermal spraying area, and can also protect the thermal spraying area, reduce the risk of erosion of the thermal spraying area by corrosive media, improve the corrosion resistance and protective effect of the entire coating, and the remelting area on the surface can enhance the adhesion of the coating and reduce the risk of peeling or falling off of the coating. Therefore, products with this corrosion-resistant coating can obtain good and lasting corrosion resistance.

[0028] In some embodiments, the remelted area is formed at an area corresponding to a preset value inward from the surface of the corrosion-resistant coating, and the preset value is 1 / 3-1 / 2 of the thickness of the corrosion-resistant coating.

[0029] In these embodiments, the remelted region is formed inwardly from the surface of the corrosion-resistant coating at a predetermined depth, thereby providing long-term corrosion protection and increasing the corrosion resistance durability of the coating. Furthermore, the remelted region has a certain thickness, which can balance the corrosion resistance of the corrosion-resistant coating with other factors, such as adhesion, surface hardness, and durability.

[0030] In some embodiments, the thickness of the corrosion-resistant coating is 30 μm-60 μm, and the preset value is 15 μm-25 μm.

[0031] In these embodiments, the thermal spray coating may have a thickness of 30 μm to 60 μm, which can, to a certain extent, avoid the risk of detachment due to high thermal stress caused by thick coatings. If the thickness of the thermal spray coating is less than 30 μm, the coating will not form easily and will not be able to completely cover the cookware substrate. If the thickness of the thermal spray coating is greater than 60 μm, the coating will suffer from high thermal stress and may be prone to collapse.

[0032] If the thickness of the remelted area is greater than 25μm, a higher temperature and longer time will be required, which may cause the ceramic layer to be overheated, resulting in overall cracking or falling off, a decrease in the strength of the remelted area, and the risk of damage to the substrate (for example, the aluminum substrate melts and deforms, the outer surface of the stainless steel substrate is severely rusted due to oxidation, etc.); if the thickness of the remelted area is less than 15μm, the rough surface formed by thermal spraying cannot be completely flattened, resulting in the final cookware surface having too high density and roughness, poor long-term corrosion resistance, and affecting later use.

[0033] When the thickness of the corrosion-resistant coating is 30μm-60μm, the thickness of the remelted area is 15μm-25μm. In this way, it can be ensured that the product with the corrosion-resistant coating has good corrosion resistance, adhesion and surface hardness.

[0034] In some embodiments, the porosity of the remelted region is 0.3%-0.5%, and the pore size is 5μm-10μm; and / or the hardness of the remelted region is 1200HV-1750HV; and / or the surface roughness of the remelted region is 0.5μm-3μm.

[0035] In these embodiments, the pore structure limited by the porosity and pore size is relatively dense, and the corrosive medium is not easy to enter, and the channel for the corrosive medium to contact the cookware substrate can be blocked, thereby further improving the corrosion resistance. The remelted area has improved hardness, so it has good wear resistance and scratch resistance, so it can extend the service life of the corrosion-resistant coating. Appropriate surface roughness can improve the lubrication properties of the coating and reduce friction and wear. The surface roughness of the remelted area according to the present application is relatively small. Smaller surface roughness can avoid the accumulation of corrosive media and reduce the possibility of corrosive media invading the coating, thereby improving the corrosion resistance of the coating. And smaller surface roughness helps to improve the flatness and smoothness of the coating surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or other features and aspects of the present invention will become clear and easily understood through the description of the embodiments in conjunction with the accompanying drawings.

[0037] Figure 1 A schematic structural diagram of a cookware according to an embodiment of the present application is shown;

[0038] Figure 2 A schematic structural diagram of a coating layer of a cookware according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0039] The specific implementation methods of the present application are described in detail below. Although some embodiments have been shown and described, it should be understood by those skilled in the art that these embodiments can be modified and improved without departing from the principles and spirit of the present application, the scope of which is defined by the claims and their equivalents.

[0040] Amorphous alloy, also known as metallic glass, is a special alloy with a disordered atomic structure similar to glass at room temperature. In the prior art, an amorphous alloy material can be used to form an amorphous alloy coating. By partially remelting the amorphous alloy coating, the pores on the surface of the amorphous alloy coating can be reduced or closed, thereby achieving the effect of isolating the corrosive medium. In this solution, the remelting of the amorphous alloy coating requires precise control of parameter conditions (e.g., controlling temperature, time, single spray thickness), etc., to ensure that the pores on the coating surface are effectively closed while also ensuring that the coating has sufficient amorphous structure. If handled improperly, remelting will cause the thermal spray coating to over-crystallize, which will reduce the volume fraction of the amorphous phase of the final coating, that is, the amorphous structure that exerts corrosion resistance will be destroyed, thereby affecting the corrosion resistance and mechanical properties of the material. In addition, complete closure of the pores is an ideal state, while reduced pores are normal. In this case, the corrosive medium can still reach between the amorphous alloy material forming the pot coating and the pot substrate, so there will be a potential difference between the two, so there will be galvanic corrosion between the coating and the pot substrate. The above two points will cause the corrosion resistance of the cookware coating to decay rapidly. In addition, the precise parameter conditions will increase the difficulty of manufacturing cookware accordingly. Moreover, the thermal spray coating formed by the amorphous alloy material will have an extremely high surface roughness due to the properties of the amorphous alloy material itself. Therefore, the amorphous alloy coating formed by thermal spraying cannot be directly remelted and requires a sanding step in advance. Only in this way can it be ensured that the surface layer of the cookware obtained by subsequent remelting has good corrosion resistance. This also means the importance of sanding the thermal spray coating in the step of manufacturing the cookware coating. If sanding is not performed, the surface roughness of the cookware coating is high and there will be more defects, such as pits, cracks and scratches. These defects can easily become the accumulation of corrosive media and the embedding points of abrasive particles, thereby accelerating the wear and corrosion process. In addition, there are many peaks and valleys on the rough surface, which makes the contact area large and prone to wear by shovels.

[0041] The inventors discovered that by thermally spraying a specific ceramic material to form a thermal spray coating, and then remelting the surface of the thermal spray coating to form the surface of the thermal spray coating into a remelting area, a cookware can be manufactured, wherein the remelting area serves as the surface layer of the cookware and has a contact surface for cooking food. The remelting area itself has improved surface hardness, smaller internal pores, and good surface properties. Therefore, using it as the surface layer of the corrosion-resistant coating can better resist erosion by corrosive media, has good corrosion resistance, and can extend the corrosion life of the coating. In addition, the surface roughness of the remelting area is suitable and can be directly used as the surface layer of the cookware (the surface layer refers to the area corresponding to the preset depth inward from the surface of the inner side of the cookware that contacts the food), thereby eliminating the subsequent sanding step. According to the method for manufacturing cookware of the present application, there is no need to precisely control the remelting process, and it is possible to achieve better corrosion resistance than the technical solution of remelting the amorphous alloy coating, and the manufacturing difficulty is greatly reduced. In addition, the appropriate roughness of the cookware surface can reduce friction noise during cooking, ensure that food does not stick, and is easy to clean, thereby providing a good user experience.

[0042] According to a first aspect of the present application, a method for manufacturing cookware is provided, wherein the method for manufacturing cookware includes forming a thermal spray coating on a cookware substrate by thermally spraying a ceramic material, and remelting the surface layer of the thermal spray coating to form a remelted area, thereby manufacturing the cookware, wherein the remelted area serves as the surface layer of the cookware, and wherein the ceramic material includes at least one of ferrosoferric oxide, iron nitride, iron carbide, and iron carbide nitrogen.

[0043] According to the method for manufacturing cookware provided in an embodiment of the present application, a thermal spray coating is formed by thermal spraying a specific ceramic material, and then the surface of the thermal spray coating is remelted to form the surface of the thermal spray coating into a remelted area, wherein the remelted area itself has improved surface hardness, smaller internal pores and good surface properties, etc., so using it as a contact surface with cooked food can better resist erosion by corrosive media, has good corrosion resistance, and can extend the corrosion resistance life of the coating.

[0044] In an embodiment of the present application, the formed pot includes a pot substrate and a corrosion-resistant coating formed on the surface of the pot substrate. The corrosion-resistant coating can be a ferroferric oxide layer, an iron nitride layer, an iron carbide layer, or a nitride iron carbide layer, or can be a composite coating formed of at least two materials selected from ferroferric oxide, iron nitride, iron carbide, and nitride iron carbide. The corrosion-resistant coating includes a thermally sprayed region and a remelted region stacked outside the thermally sprayed region, that is, the corrosion-resistant coating includes an internal thermally sprayed region and a remelted region on the surface. The remelted region serves as the surface layer of the pot.

[0045] In these embodiments, the remelted area is located on the outside and can also protect the thermal spraying area, reduce the risk of erosion of the thermal spraying area by corrosive media, improve the corrosion resistance and protective effect of the entire coating, and the remelted area on the surface can enhance the adhesion of the coating and reduce the risk of peeling or falling off of the coating. Therefore, products with this corrosion-resistant coating can obtain good and lasting corrosion resistance.

[0046] In an embodiment of the present application, a local area of ​​the thermal spray coating can be remelted. As an example, the surface area of ​​the thermal spray coating can be remelted. The local remelting treatment of the thermal spray coating can avoid the brittleness and increased thermal stress caused by the film layer being too dense, and can ensure the overall performance of the cookware coating. In this way, the quality of the cookware coating can be further improved to meet the user's usage needs. In this case, the formed cookware includes a cookware base and a corrosion-resistant coating located on the surface of the cookware base, wherein the corrosion-resistant coating includes a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area, and the remelting area serves as the surface layer of the corrosion-resistant coating. Among them, the thermal spraying area inside the corrosion-resistant coating is the remaining thermal spraying layer, and the remaining thermal spraying layer is the thermal spraying layer of the portion that has not been remelted, or in other words, before the remelting process, the internal area of ​​the thermal spraying layer still retains a porous structure. The porous structure can play a shock-absorbing role, so that the impact energy of the pot during use can be buffered and the stress can be dispersed, thereby reducing the possibility of stress concentration, reducing the risk of damage to the coating and the substrate (for example, cracks, peeling and wear, etc.), and increasing the durability and performance stability of the pot. The remelting area located on the surface of the corrosion-resistant coating is the thermal spraying layer of the portion that has been remelted. In this area, this part of the thermal spraying layer has been remelted, so that it melts to a certain extent and forms a denser structure. The presence of the remelting area can further improve the compactness and corrosion resistance of the corrosion-resistant coating. As above, the structure of the corrosion-resistant coating combines the thermal spraying area and the remelting area so that the pot can take into account both corrosion resistance and shock absorption function.

[0047] It should be noted that the “thermal spray coating” and “thermal spray area” mentioned in this application are both layers formed by thermal spraying, and the distinction here is only made in terms to distinguish the layers at different stages of cookware manufacturing.

[0048] Hereinafter, the method for manufacturing a cookware according to the present application will be described in detail.

[0049] Prepare the cookware base

[0050] In the prior art, chemical nitriding and high-temperature oxidation corrosion protection methods have certain limitations on the choice of substrates and are usually only applicable to iron-based substrates, and cannot be applied to aluminum-based substrates, titanium-based substrates, etc.

[0051] According to the present application, the base of the cookware can adopt the base of the prior art for manufacturing cookware. In an embodiment, the base of the cookware can include an aluminum base, an iron base, a magnesium base, a copper alloy base, an alumina base, a stainless steel base, a titanium base, and a composite base formed by the above various bases. Among them, the composite base is a structure in which multiple bases are stacked, for example, it can include a three-layer composite base such as titanium-aluminum-stainless steel. It should be noted that in the case where the base of the cookware is an aluminum base, a magnesium base, an iron base, and a composite base formed by at least two metals of aluminum, magnesium, and iron, since aluminum, magnesium, and iron are all materials that are easily oxidized, when the base of the cookware includes a surface formed by aluminum, magnesium, or iron, corrosion will easily occur, which limits the materials for manufacturing the cookware.

[0052] To this end, the method for manufacturing cookware according to the present application includes remelting a thermal spray coating formed of a ceramic material. In this way, after the remelting process, the surface layer of the thermal spray coating can be transformed into a structural layer that is denser than its interior. In this case, the pores in the interior and the surface layer are blocked, so that the corrosive medium is not easy to penetrate into the base area of ​​the cookware, thereby ensuring the corrosion resistance and bonding strength of the cookware as a whole. In this case, the corrosive medium during cooking does not easily contact the base, which can ensure a longer corrosion resistance life. In addition, the method for manufacturing cookware can also be applied without any special restrictions on the type of base. Therefore, the method according to the present application can be applied to a wider variety of bases, thereby expanding the range of bases that can be adapted to cookware manufacturing and having better versatility.

[0053] In addition, when the cookware base is a composite matrix formed by at least two metals among an aluminum matrix, a magnesium matrix and an iron matrix, the weight of the formed cookware can be greatly reduced due to the inclusion of relatively light aluminum and magnesium, which is extremely beneficial for the elderly and others with less strength.

[0054] According to the present application, after selecting the cookware substrate, the method for manufacturing the cookware further includes performing alkaline washing, degreasing, and drying operations on the surface of the cookware substrate to avoid affecting the bonding strength between the subsequent coating and the cookware substrate.

[0055] Prepare ceramic materials

[0056] Corrosion can be caused by rust and galvanic corrosion. According to the present application, ceramics are typically non-metallic materials. Due to their inherent properties, the conditions necessary for galvanic corrosion to form between the ceramic material and the cookware base are lacking (for example, there is a lack of good electron and ion conduction between them, which is not conducive to the formation of a potential difference between the ceramic and metal base). Therefore, the layer formed by thermal spraying the ceramic material will not undergo galvanic corrosion with the metal base, thereby further ensuring the corrosion resistance of the resulting cookware.

[0057] It should be noted that the ceramic material of the present application includes at least one of ferroferric oxide, iron nitride, iron carbide, and nitrided iron carbide, which can be obtained commercially and is a pure ceramic material. It does not contain metal powder or alloy powder. This is because the introduction of metal powder will easily generate a potential difference between the formed layer and the cookware substrate, which may cause galvanic corrosion, which will accelerate the corrosion and shedding of the cookware coating. It should be noted that when the ceramic material includes a mixture of two or more of ferroferric oxide, iron nitride, iron carbide, and nitrided iron carbide, the present application does not intentionally limit the mixing ratio of the mixture.

[0058] In some embodiments, the ceramic material is in granular form and includes at least one of ferroferric oxide, iron nitride, iron carbide, and iron carbide nitride. These materials have good corrosion resistance and are black in color, resulting in a thermal spray coating with a certain degree of corrosion resistance and anti-fouling properties. Specifically, ferroferric oxide easily forms a ferroferric oxide film during use that effectively isolates the cookware from moisture and oxygen, preventing the cookware substrate from contacting these corrosive media, thereby improving the cookware's corrosion resistance. Iron nitride easily forms an iron nitride layer, which provides high hardness and good wear and corrosion resistance. After treatment under certain conditions, this coating can also improve the cookware's wear resistance. Iron carbide is commonly found in the microstructure of steel and can increase the material's hardness and strength. Therefore, in cookware, an appropriate amount of carbide can help improve corrosion resistance and provide a certain degree of heat resistance. In addition, iron carbide nitride can combine the advantages of carbides and nitrides to provide additional hardness and stability. Therefore, the thermal spray coating formed of the above materials can itself have certain durability and corrosion resistance.

[0059] In some embodiments of the present application, when the ceramic material is granular, the particle size of the ceramic material is in the range of 200-300 mesh. If the particle size of the ceramic material is greater than 200 mesh, the pores of the thermal spray coating formed may be too large and the surface may be rougher due to the excessively large material particles, thereby increasing the time for subsequent remelting treatment and weakening the corrosion resistance of the formed pot. In addition, if the particles are too large, the particles will rebound after hitting the surface of the substrate, thereby reducing the deposition efficiency of the material and wasting raw materials. In addition, if the material particles are too large, the spraying construction performance is poor, which can easily cause uneven film thickness of the thermal spray coating. If the particle size of the corrosion-resistant material is less than 300 mesh, the particles may be too small, resulting in construction difficulties during the plasma spraying process (for example, the powder is easy to agglomerate, resulting in uneven powder feeding due to poor powder fluidity; the powder is too small and the weight is too light, resulting in insufficient flight speed, reducing deposition efficiency, and wasting raw materials).

[0060] In other embodiments of the present application, when the ceramic material is granular, the ceramic particles exist in the form of multiple particle sizes. By selecting a powder of a combination of large and small particles as the ceramic material of the present application, a thermal spray coating in which the particles are closely packed together can be obtained, thereby reducing the porosity of the coating.

[0061] Specifically, the particle size R of the ceramic granular material has multiple distribution ranges, wherein the multiple distribution ranges include a first distribution range, a second distribution range and a third distribution range. The first distribution range is 200 mesh ≤ R < 300 mesh, the second distribution range is R > 200 mesh, and the third distribution range is R ≤ 300 mesh. Among them, based on the total volume of the ceramic material in the mixture as 100%, the volume of the ceramic material with a particle size in the first distribution range accounts for 93%-95%, the volume of the ceramic material with a particle size in the second distribution range accounts for 1%-2%, and the volume of the ceramic material with a particle size in the third distribution range accounts for 3%-5%. It should be noted that particles in multiple distribution ranges can be obtained by grinding and screening.

[0062] Forming thermal spray coating

[0063] According to the present application, the thermal spray coating can be at least partially formed on the inner and / or outer surfaces of the cookware base. In other words, the thermal spray coating can cover part or all of the surface of the cookware base, where the surface can be the inner and / or outer surface. The thermal spray coating is formed by thermally spraying the ceramic material provided in the embodiments of the present application, thereby having non-stick properties and improved hardness.

[0064] According to some embodiments of the present application, a ceramic material is thermally sprayed onto the surface of a cookware substrate to form a thermal spray coating on the surface of the cookware substrate. During the thermal spraying process, powdered ceramic particles are heated to a molten or semi-molten state and sprayed onto the surface of the cookware substrate at an extremely high speed, and a strong thermal spray coating is formed after cooling. Thermal spraying can be performed by plasma spraying. Specifically, the ceramic material is placed in a powder feeder of a plasma spraying device, the ceramic tank is evacuated to 3Pa-5Pa, and argon gas is injected to 5×10 3 -10×10 3 Pa. Using plasma arc ignition, the ceramic material melts and adheres to the surface of the cookware substrate, forming a thermal spray coating. The plasma arc power is set to 30kW-55kW, the arc current is set to 300A-700A, the spraying distance is set to 100mm-150mm, the spraying angle is set to 60°-80°, the powder feeding rate is set to 25g / min-45g / min, the hydrogen pressure is set to 0.3MPa-0.5MPa, and the hydrogen flow rate is set to 3L / min-8L / min. The cookware substrate is preheated to 200°C-250°C before spraying and cooled with a 5°C-15°C cold air gun after spraying.

[0065] According to the present application, by performing thermal spraying on a ceramic material within the above-mentioned process parameter range, a corrosion-resistant coating having a suitable thickness and a smooth surface obtained only by remelting can be formed on the surface of the substrate. The corrosion-resistant coating has properties similar to those of the ceramic material and can therefore have excellent properties such as high hardness, thermal stability, wear resistance, and resistance to chemical corrosion. In other words, the corrosion-resistant coating conceived according to the present invention can retain the various properties of the ceramic material therein, and the surface layer is formed into a remelted area with low porosity, pores, and roughness, which, as the surface layer of the cookware, can ensure the corrosion resistance of the cookware.

[0066] In existing technologies, amorphous alloy coatings can cause galvanic corrosion with the cookware substrate due to the potential difference, so a thickness of 200μm-500μm is required to ensure corrosion resistance. However, if the thickness is thicker than conventional coatings, the coating is prone to peeling.

[0067] According to the present application, there is no potential difference between the ceramic material and the substrate, and galvanic corrosion will not occur. In addition, the present application can adopt a thickness that is not easy to peel off, thereby achieving better corrosion resistance and bonding strength than the aforementioned. According to the present application, the thermal spray coating can have a thickness of 30μm-60μm, which can, to a certain extent, avoid the risk of detachment due to the thick coating and high thermal stress. If the thickness of the thermal spray coating is less than 30μm, the coating is not easy to form a film and cannot completely cover the cookware substrate. If the thickness of the thermal spray coating is higher than 60μm, the thermal stress of the coating is high and it is easy to collapse.

[0068] In some embodiments, the formed thermal spray coating has a certain porosity and pore size, which makes it easier for the corrosive medium to penetrate into the substrate. As an example, the porosity of the thermal spray coating is 3-8%, and the pore size is in the range of 15μm-25μm. In addition, due to the influence of the spraying process, the surface of the thermal spray coating has a certain rough structure. As an example, the surface roughness of the thermal spray coating is 5μm-7μm. Such a rough surface will weaken the corrosion resistance and is not suitable for being directly used as the surface of the cookware in contact with the food. The hardness is 1200HV-1750HV, and the durability is average. In this case, the corrosion resistance of the thermal spray coating directly used as the cookware coating is extremely poor. Therefore, it is extremely necessary to perform certain treatments on the thermal spray coating.

[0069] Formation of remelting area on the surface of thermal spray coating

[0070] According to the present application, the surface layer of the thermal spray coating is remelted to form a remelting area, wherein the remelting process refers to melting the surface layer of the thermal spray coating that has been solidified and formed again, and then rapidly cooling it in a certain way to form a new organizational structure and properties. Through appropriate remelting treatment, defects and internal stresses in the thermal spraying process, such as pores, inclusions and cracks, etc., can be eliminated, and grains can be refined to obtain a remelting area with a higher density, so that the surface density of the final coating (i.e., the corrosion-resistant coating to be described below) is higher. Electron beam remelting can promote better bonding between the coating and the substrate, enhance the adhesion and stability of the coating, and avoid the situation where the corrosion resistance is too poor due to shedding of the coating. In addition, the surface properties, improved hardness and wear resistance of the final coating can also be improved through remelting treatment.

[0071] In the prior art, remelting treatments can include electron beam remelting (EBM) or laser remelting. Currently, laser remelting methods have a small laser spot size, high material surface reflectivity, and only a 5-10% utilization rate. Furthermore, the processing power is too high, making it suitable for amorphous materials but not for ceramic materials. Therefore, in this application, a pulsed electron beam remelting method is used to perform remelting treatment on thermal spray coatings formed from ceramic materials. The pulsed electron beam has highly concentrated energy. By using the electron beam for rapid heating, a high-energy-density heat treatment can be provided in a very short time, instantly melting the surface layer of the thermal spray coating. This is then cooled and rapidly solidified, forming a new surface area, i.e., the remelted area. In this process, the pulsed electron beam method can reduce the heat-affected zone (HAZ), thereby controlling the thermal effects during coating processing and avoiding structural damage caused by excessive thermal effects, the generation of large amounts of thermal stress and residual stress, and the occurrence of defects such as poor melting, pores, and inclusions. Furthermore, pulsed electron beams can instantly heat thermal spray coatings in a very short time, achieving a localized remelting effect and reducing heat conduction and thermal impact on the substrate. This helps the coating be applied to a wider range of substrates while maintaining the substrate's original performance and dimensional stability. Overall, electron beam remelting makes it easier to control coating quality.

[0072] According to the present application, a more uniform microstructure can be obtained by electron beam remelting treatment, so that the coating surface of the cookware forms a smoother and more uniform structure, reducing defects such as cracks and pores, and improving wear resistance. In addition, there will be large internal stress in the thermal spray coating during the formation process, which will also affect the corrosion resistance and mechanical properties of the cookware coating. These stresses can be released and redistributed through remelting treatment, thereby improving the performance of the cookware coating. In addition, remelting of the thermal spray coating formed by a variety of ceramic materials can cause the microstructure of the coating to change, from an amorphous or crystalline state to a more stable form, which may lead to increased hardness, wear resistance and enhanced antioxidant properties. In addition, the surface layer of the thermal spray coating is remelted, and the remelted area obtained has good heat resistance, which can ensure the thermal stability of the coating.

[0073] In the present application, the remelted region itself has improved surface hardness, smaller internal pores, and good surface properties. The remelted region serves as the surface layer of the cookware, that is, the surface layer of the cookware has improved properties. Such a cookware can resist erosion by corrosive media, thereby extending the corrosion life of the cookware. In addition, the density of the pores on the surface and inside the cookware coating (i.e., the corrosion-resistant coating to be described below) is different, which will inevitably greatly reduce the number of pores that directly pass from the outside to the cookware substrate. In this way, it is possible to block external corrosive conditions from entering the cookware substrate, avoid the situation where the corrosion resistance is too poor due to coating shedding, and ensure the corrosion resistance of the entire cookware. In this case, there is no need to limit the material of the cookware substrate, making the method of manufacturing cookware of the present application applicable to a wider variety of cookware substrates.

[0074] Traditional coatings may require a transition layer or a primer layer to improve the adhesion between the coating and the substrate. According to the present application, the substrate surface can be partially melted during the remelting process, so that the thermal spray coating and the substrate are mixed at the molecular level, strengthening their adhesion, thereby improving the overall mechanical strength of the coating. Therefore, the method of manufacturing cookware in the present application can eliminate the step of setting a transition layer (priming layer) and simplify the production process.

[0075] In the prior art, in the process of remelting the amorphous alloy coating, it is necessary to precisely control parameters (for example, temperature and time) to ensure the effective closure of the pores on the coating surface and to ensure that the coating still maintains a certain amorphous structure. However, according to the present application, the thermal spray coating formed of ceramic materials is remelted without the need to precisely control the various parameters, which can reduce the difficulty of production control to a certain extent. According to the present application, the remelting process can be performed by using a pulsed electron beam. Before the pulsed electron beam treatment, only key parameters such as pulse duration, energy density and number of repetitions need to be roughly determined. These parameters can ensure that the thermal spray coating obtains sufficient energy for remelting while avoiding overheating or damage, and there is no need to precisely control the various parameters. In some embodiments, the specific process parameters of the electron beam remelting process include: electron beam power of 25Kev-35Kev; energy density of 3J.cm 2 -6J.cm 2 ; Pulse duration is 1μS-3μS; vacuum degree is 1×10 -3 Pa-2×10 -3 Pa; electron beam spot size 50mm-80mm. Under the above parameters, the pulsed electron beam can treat the surface layer of the thermal spray coating at an appropriate temperature for a certain period of time, for example, a temperature of approximately 2000℃-2500℃ for a time of 1μs-3μs, thereby forming a remelted layer with good performance while avoiding excessive remelting and affecting the substrate.

[0076] Compared to laser treatment, pulsed electron beam treatment has lower power and is less likely to cause excessive surface remelting during treatment. Therefore, multiple treatments are required to achieve the desired effect. However, it should be noted that more treatments are not necessarily better. The number of treatments can be set based on the surface defects of the thermal spray coating, such as the degree of roughness. As an example, the number of repetitions of electron beam remelting in the cookware manufacturing method according to the present application can be 10-20 times.

[0077] According to the present application, performing an appropriate number of electron beam remelting on the surface layer of the thermal spray coating can enhance the density of the surface layer, improve the grain refinement and adhesion of the surface layer. Specifically, after multiple remelting treatments, the surface layer of the thermal spray coating becomes denser, which can prevent corrosive substances from penetrating into the interior of the remelting area, thereby improving the corrosion resistance of the coating. In addition, multiple remelting treatments can eliminate defects in the surface layer, make the surface smoother, reduce surface flaws and unevenness, and thus improve the surface quality of the coating. In addition, multiple remelting treatments can reduce the grain size of the surface layer, make the surface layer denser, and improve the adhesion of the surface layer, improve the bonding between the surface layer and the substrate, and increase the thermal conductivity of the coating, thereby improving the heating efficiency of the cookware. In summary, multiple electron beam remelting treatments help to improve the quality of the thermal spray coating and improve the performance of the cookware.

[0078] According to the present application, the remelted region is formed in the surface layer of the thermal spray coating, where the surface layer of the thermal spray coating refers to the area corresponding to a certain thickness from the surface to the inside of the thermal spray coating. As an example, the thickness of the thermal spray coating is 30μm-60μm, and the preset value is 1 / 3-1 / 2 of the thickness of the thermal spray coating. Here, the thickness is determined by the pulse duration, energy density, and number of repetitions. As an example, the thickness can be 15μm-25μm.

[0079] According to the present application, the porosity of the remelted area is 0.3%-0.5%; the pore size is 5μm-10μm, and / or the hardness of the remelted area is 1200HV-1750HV; and / or the surface roughness of the remelted area is 0.5μm-3μm.

[0080] According to the cookware manufacturing method of the present application, sanding of the remelted area after the remelting process is not required. This is because the remelting process has already sufficiently improved the surface quality of the coating, ensuring that the cookware surface meets corrosion resistance requirements and making the cookware surface smoother and more uniform. This simplifies the process steps, reduces manufacturing costs by eliminating the need for sanding, and improves production efficiency.

[0081] Ceramic coatings and amorphous alloy coatings have different physical and chemical properties, and these differences lead to different requirements for their surface treatment after thermal spraying. Although amorphous alloy coatings generally have better wear and corrosion resistance, they may form irregular connections between larger particles and the coating substrate, as well as tiny defects, during the thermal spraying process. Without sanding, these defects can easily become embedding points for abrasive particles and accumulation points for corrosive media, thereby accelerating the wear and corrosion process. Furthermore, rough surfaces have more peaks and valleys, resulting in a larger actual contact area and more severe wear. Therefore, sanding is extremely necessary before remelting the amorphous alloy coating; otherwise, it is difficult to ensure corrosion resistance and durability.

[0082] However, thermal spray coatings made of ceramic materials have strong adhesion and good coating smoothness, so sanding is not required after coating to achieve the desired surface roughness and quality. Therefore, according to the method for manufacturing cookware of the present application, sanding of the thermal spray coating is not required before the remelting process, while ensuring corrosion resistance and durability. This can shorten the steps in manufacturing the cookware and simplify the manufacturing process.

[0083] According to the present application, ceramic materials with lower costs than amorphous materials are used to obtain corrosion resistance comparable to that of amorphous alloy coatings, and steps in the manufacturing process are reduced, production efficiency is improved, and better economic benefits are achieved.

[0084] According to the present application, the remelted coating forms the final surface layer of the cookware (i.e., the corrosion-resistant coating). The surface of the surface layer can serve as the inner surface of the cookware that comes into contact with food during use, while the surface opposite the inner surface serves as the outer surface of the cookware. The inner surface and outer surface herein are generally understood by those skilled in the art as inner and outer surfaces.

[0085] According to a second aspect of the present application, a cookware is provided, wherein the cookware includes a cookware substrate and the corrosion-resistant coating provided in the above-mentioned embodiments formed on the surface of the cookware substrate, wherein the corrosion-resistant coating is formed of at least one of ferroferric oxide, iron nitride, iron carbide and nitrided iron carbide, that is, the corrosion-resistant coating can be a ferroferric oxide layer, an iron nitride layer, an iron carbide layer or a nitrided iron carbide layer, or it can be a composite layer formed of at least two materials of ferroferric oxide, iron nitride, iron carbide and nitrided iron carbide, and the corrosion-resistant coating includes a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area.

[0086] According to the corrosion-resistant coating provided in the embodiment of the present application, the corrosion-resistant coating is a ferroferric oxide layer, an iron nitride layer, an iron carbide layer or a nitride iron carbide layer. Due to the inherent characteristics of the forming material, the corrosion-resistant coating itself has a certain corrosion resistance. The corrosion-resistant coating includes a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area, that is, the corrosion-resistant coating includes a thermal spraying area inside the corrosion-resistant coating and a remelting area connected to the outside of the thermal spraying area and on the surface of the corrosion-resistant coating. The remelting area itself has improved surface hardness, smaller internal pores and good surface properties, etc., so it can be used as the surface layer of the corrosion-resistant coating to better resist erosion by corrosive media, has good corrosion resistance, and can extend the corrosion life of the coating. The remelting area is located outside the thermal spraying area, and can also protect the thermal spraying area, reduce the risk of erosion of the thermal spraying area by corrosive media, improve the corrosion resistance and protective effect of the entire coating, and the remelting area of ​​the surface can enhance the adhesion of the coating, reduce the risk of peeling or falling off of the coating, so the product with the corrosion-resistant coating can obtain good and lasting corrosion resistance.

[0087] It should be noted that in this application, the thermal spray coating and the corrosion-resistant coating are products of different stages of the cookware manufacturing process. The thermal spray coating is presented during the method process, while the corrosion-resistant coating is presented in the final product.

[0088] In some embodiments, the remelting area is located on the surface of the corrosion-resistant coating and has a preset value, and the preset value is 1 / 3-1 / 2 of the thickness of the corrosion-resistant coating.

[0089] In these embodiments, the remelted region is located at a predetermined thickness on the surface of the corrosion-resistant coating, thereby providing long-term corrosion protection and increasing the corrosion resistance durability of the coating. Furthermore, the remelted region has a predetermined thickness, which balances the corrosion resistance of the corrosion-resistant coating with other factors, such as adhesion, surface hardness, and durability.

[0090] In some embodiments, the thickness of the corrosion-resistant coating is 30μm-60μm, and the preset value is 15μm-25μm. In this embodiment, the preset value is 15μm-25μm, which is the thickness of the remelting area. If the thickness of the remelting area is greater than 25μm, a higher temperature and a longer time are required, which may cause the ceramic layer to be overheated, resulting in overall cracking or falling off, a decrease in the strength of the remelting area, and the risk of damage to the substrate (for example, the aluminum substrate melts and deforms, the outer surface of the stainless steel substrate is severely rusted due to oxidation, etc.); if the thickness of the remelting area is less than 15μm, the rough surface formed by thermal spraying cannot be completely flattened, resulting in the density and roughness of the final pot surface being too high, the long-term corrosion resistance effect is poor, and it affects later use.

[0091] In these embodiments, when the thickness of the corrosion-resistant coating is 30 μm-60 μm, the thickness of the remelted area is 15 μm-25 μm, so that the product with the corrosion-resistant coating can have good corrosion resistance, adhesion and surface hardness.

[0092] In some embodiments, the porosity of the remelted region is 0.3%-0.5%, and the pore size is 5 μm-10 μm.

[0093] In these embodiments, the pore structure under such porosity and pore size limitations is relatively dense, making it difficult for corrosive media to enter, and can block the channels through which the corrosive media contact the cookware substrate, thereby further improving the corrosion resistance.

[0094] In some embodiments, the hardness of the remelted region is 1200 HV-1750 HV.

[0095] In these embodiments, the remelted region has improved hardness, thus having good wear and scratch resistance, thereby extending the service life of the corrosion-resistant coating.

[0096] In some embodiments, the surface roughness of the remelted region is 0.5 μm-3 μm.

[0097] In these embodiments, a suitable surface roughness can improve the coating's lubricity and reduce friction and wear. The remelted area according to the present application has a relatively low surface roughness. This low surface roughness can prevent the accumulation of corrosive media and reduce the likelihood of corrosive media invading the coating, thereby improving the coating's corrosion resistance. Furthermore, a low surface roughness helps improve the coating's surface flatness and finish.

[0098] In some embodiments, the remelted region is formed by performing a pulsed electron beam on a thermal spray coating formed of ferroferric oxide, iron nitride, iron carbide, or iron nitride carbide.

[0099] In these embodiments, pulsed electron beam treatment features rapid heating and cooling. By performing pulsed electron beam treatment on a thermal spray coating composed of ferroferric oxide, iron nitride, iron carbide, or iron carbide nitride, a remelted region with improved surface properties and enhanced bonding strength can be formed, thereby improving the corrosion resistance of the overall coating. Furthermore, during the pulsed electron beam treatment, the energy of the pulsed electron beam can be controlled to ensure that only the surface layer of the thermal spray coating is treated without affecting the substrate.

[0100] In some embodiments, the thermal spraying region is formed by plasma spraying, wherein the thermal spraying region may be a portion of the thermal spraying layer that has not been subjected to a remelting process.

[0101] In these embodiments, the thermal spraying region is formed by utilizing the high temperature and high-speed spraying of plasma. The obtained coating has good bonding with the substrate and a certain density. Moreover, this method of forming the layer is more efficient and faster.

[0102] In some embodiments, the cookware substrate includes an aluminum substrate, an iron substrate, a magnesium substrate, a copper alloy substrate, an alumina substrate, a stainless steel substrate or a titanium substrate, as well as a composite substrate formed by the above substrates.

[0103] In these embodiments, the corrosion-resistant coating can be located on various types of cookware substrates, and the substrates have a wider range of applications.

[0104] According to the present application, the cookware provided in the embodiments of the present application can be manufactured using the cookware manufacturing method according to the first aspect of the present application. Specifically, a thermal spray coating can be formed by thermally spraying a ceramic material onto a cookware substrate, and the surface layer of the thermal spray coating is remelted to form a remelted region, thereby manufacturing the cookware. The remelted region serves as the surface layer of the cookware, and the ceramic material includes at least one of ferrosoferric oxide, iron nitride, iron carbide, and iron carbide nitride. The coating of the resulting cookware is the corrosion-resistant coating described above.

[0105] like Figure 1 and Figure 2As shown, the cookware includes a cookware base 10 and a corrosion-resistant coating 20 located on the surface of the cookware base 10, wherein the corrosion-resistant coating 20 includes a thermal spraying area 21 located inside and a remelting area 22 located on the surface, wherein the thermal spraying area 21 is the portion of the thermal spraying layer that has not been remelted, and can also be called the remaining thermal spraying layer, and the remelting area 22 is the surface portion of the thermal spraying layer that has been remelted. The remelting area is obtained by remelting the surface layer of the thermal spraying layer formed of a ceramic material, and the remelting area 22 is located on the surface of the thermal spraying layer formed of the ceramic material from the outside to the inside, and has a preset value.

[0106] Of course, the present application is not limited to this. Ceramic material can also be used to form an internal thermal spraying area on the cookware base first, and then ceramic material can be continued to be sprayed on the thermal spraying area to form a coating, and the coating can be remelted as a whole, so as to form a corrosion-resistant coating according to the present application, including a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area, and the remelting area serves as the surface layer of the corrosion-resistant coating.

[0107] According to the present application, the hardness and density are improved, the anti-fouling property is better, the scratching and friction sound of food, spatulas, etc. during cooking is smaller, and the corrosion resistance is also better.

[0108] In the embodiment, the surface roughness of the remelted area is 0.5 μm-3 μm. Compared with the thermal spray coating, the roughness is significantly reduced. On the one hand, it is not easy for corrosive media to accumulate, which can improve corrosion resistance. On the other hand, it can reduce friction noise during cooking, ensure that food does not stick, and is easy to clean, thus providing a good user experience.

[0109] The present application will be described in detail below with reference to the embodiments, but the protection scope of the present application is not limited to the embodiments.

[0110] Example 1

[0111] The cookware according to Example 1 was prepared by the following method.

[0112] Step S10: Provide a 1.8mm thick stainless steel cookware base. Pre-treat the surface of the cookware by cleaning the surface oil with an alkaline solvent, then rinsing with clean water and drying. Then, sandblast the surface to roughen it. Then, preheat the cookware to 230°C in a furnace.

[0113] Step S20: providing a ceramic material. Provide ferrosoferric oxide with an average particle size of 200 mesh as the ceramic material.

[0114] Step S30: preparing a thermal spray coating.

[0115] Step S31: placing the outer surface of the cookware in a circulating cooling air environment, with the temperature of the cooling air set at -10°C.

[0116] Step S32: The vacuum degree of the spraying chamber is reduced to 3 Pa, and then argon gas is injected to 6×10 3 Pa. The ceramic material is placed in the powder feeder of the plasma spraying equipment, and the ferroferric oxide is thermally sprayed on the preheated pot body surface by plasma arc ignition, and a thermal spray layer with a thickness of 40μm is sprayed. Among them, the plasma arc power is set to 30Kw, the arc current is set to 700A, the spraying distance is set to 120mm, the spraying angle is set to 70°, the powder feeding speed is set to 25g / min, the hydrogen pressure is set to 0.5MPa, and the flow rate is set to 7L / min. Under the above parameters, the high-pressure plasma flame flow formed at the muzzle heats the surface of the ceramic material to melt, and then deposits it on the surface of the cookware substrate to form a thermal spray layer with a thickness of 40μm on the cookware substrate.

[0117] In step S40 , a remelting process is performed on the thermal spray coating to form a remelting region with a preset depth on the surface layer of the thermal spray coating.

[0118] The thermal spray coating was remelted by a pulsed electron beam method, wherein the setting parameters of the pulsed electron beam were: electron beam power of 25Kev; electron beam energy of 3J.cm 2 ; Processing time is 1μS; Vacuum degree is 1*10 -3 Pa; electron beam spot size 80 mm. The thermal spray coating was treated 10 times using the same parameters and then naturally cooled to room temperature, thereby obtaining a pot with a remelted area with a thickness of 15 μm.

[0119] Example 2

[0120] The cookware of Example 2 was prepared by the same method as that of Example 1, except that the thermal spraying material of Example 1 was replaced by iron nitride.

[0121] Example 3

[0122] The cookware of Example 3 was prepared by the same method as that of Example 1, except that the thermal spraying material of Example 1 was replaced by iron carbide.

[0123] Example 4

[0124] The cookware of Example 4 was prepared by the same method as that of Example 1, except that the thermal spraying material of Example 1 was replaced by iron carbonitride.

[0125] Example 5

[0126] The cookware of Example 5 was prepared by the same method as that of Example 1, except that the thermal spraying material of Example 1 was replaced by a mixture of ferrosoferric oxide and iron carbonitride in a mass ratio of 1:1.

[0127] Example 6

[0128] The cookware of Example 6 was prepared by the same method as that of Example 1, except that the thermal spraying material of Example 1 was replaced by a mixture of ferrosoferric oxide and iron carbide in a mass ratio of 1:1.

[0129] Example 7

[0130] The cookware of Example 7 was prepared using the same method as that of Example 1, except that the aluminum substrate of Example 1 was replaced by an iron substrate.

[0131] Example 8

[0132] The cookware of Example 8 was prepared by the same method as that of Example 1, except that the aluminum substrate of Example 1 was replaced by an alumina substrate.

[0133] Example 9

[0134] The cookware of Example 9 was prepared by the same method as that of Example 1, except that the aluminum substrate of Example 1 was replaced by an iron alloy substrate.

[0135] Example 10

[0136] The cookware of Example 10 was prepared by the same method as that of Example 1, except that the aluminum substrate of Example 1 was replaced by a copper substrate.

[0137] Example 11

[0138] The cookware of Example 11 was prepared by the same method as that of Example 1, except that the average particle size of ferrosoferric oxide in Example 1 was changed from 200 mesh to 300 mesh.

[0139] Example 12

[0140] The cookware of Example 12 was prepared by the same method as in Example 1, except that the average particle size of ferrosoferric oxide in Example 1 was replaced with a multi-particle size form (i.e., the first distribution interval was 200 mesh ≤ R < 300 mesh, the second distribution interval was R > 200 mesh, and the third distribution interval was R ≤ 300 mesh, wherein, based on the total volume of the ceramic material in the mixture being 100%, the volume of the ceramic material with a particle size in the first distribution interval accounted for 94%, the volume of the ceramic material with a particle size in the second distribution interval accounted for 2%, and the volume of the ceramic material with a particle size in the third distribution interval accounted for 4%).

[0141] Comparative Example 1

[0142] Except that the thermal spraying material of Example 1 is replaced by Fe 80 -Cr5-Mo6-B4-Si5, the cookware of Comparative Example 1 was prepared by the same method as that of Example 1.

[0143] Comparative Example 2

[0144] In addition to replacing the thermal spraying material of Example 1 with Zr 60 -Cr 20 -Nb 13 -Ni5-Hf2, the cookware of Comparative Example 2 was prepared by the same method as that of Example 1.

[0145] Comparative Example 3

[0146] The cookware of Comparative Example 3 was prepared by the same method as that of Example 1, except that the thermal spray coating of Example 1 was not subjected to the remelting treatment (ie, step S40 was not included).

[0147] Comparative Example 4

[0148] The cookware of Comparative Example 4 was prepared by the same method as that of Example 2, except that the thermal spray coating of Example 2 was not subjected to the remelting treatment (ie, step S40 was not included).

[0149] Comparative Example 5

[0150] The cookware of Comparative Example 5 was prepared by the same method as that of Example 3, except that the thermal spray coating of Example 3 was not subjected to the remelting treatment (ie, step S40 was not included).

[0151] Comparative Example 6

[0152] The cookware of Comparative Example 6 was prepared by the same method as that of Example 4, except that the thermal spray coating of Example 4 was not subjected to the remelting treatment (ie, step S40 was not included).

[0153] Comparative Example 7

[0154] The cookware of Comparative Example 7 was prepared by the same method as that of Example 5, except that the thermal spray coating of Example 5 was not subjected to the remelting treatment (ie, step S40 was not included).

[0155] Comparative Example 8

[0156] The cookware of Comparative Example 8 was prepared by the same method as that of Example 6, except that the thermal spray coating of Example 6 was not subjected to the remelting treatment (ie, step S40 was not included).

[0157] Comparative Example 9

[0158] The cookware of Comparative Example 9 is prepared by the same method as that of Example 1, except that the thermal spray coating of Example 1 is not subjected to the remelting treatment step (i.e., step S40 is not included) and the thermal spray coating of Example 1 is filled with a sealant (the sealant is silica sol).

[0159] Comparative Example 10

[0160] The cookware of Comparative Example 10 is prepared by the same method as that of Example 2, except that the thermal spray coating of Example 2 is not subjected to the remelting treatment step (i.e., step S40 is not included) and the thermal spray coating of Example 2 is filled with a sealant (the sealant is silica sol).

[0161] Comparative Example 11

[0162] (1) Preparation of amorphous alloy powder

[0163] The five metal materials, Fe, Cr, Mo, B, and Si, are blended according to the atomic percentage content of the alloy chemical formula Fe80-Cr5-Mo6-B4-Si5. The above alloy raw materials are smelted in a melting furnace to form an iron-based molten alloy liquid. The iron-based molten alloy liquid is sprayed onto a high-speed rotating copper quench plate. Under the action of centrifugal force, the iron-based molten alloy liquid is atomized and solidified into fine particles that spread out in all directions. Inert gas is sprayed through gas nozzles installed around the quench plate to accelerate the cooling of the fine particles, forming an iron-based amorphous alloy powder.

[0164] (2) Preparation of amorphous alloy coating

[0165] Step (a): Pre-treat the surface of the cookware

[0166] Use an alkaline solvent to clean the surface of the pot to remove oil stains, then rinse with clean water and dry. Then, sandblast the surface to roughen it.

[0167] Step (b): Preheat the pot

[0168] Preheat the pot to 230°C in a heating furnace.

[0169] Step (c): Forming an amorphous alloy coating

[0170] The vacuum degree of the spray chamber was reduced to 3 Pa, and then argon gas was injected to 6×10 3Using plasma arc ignition, iron-based amorphous alloy powder was thermally sprayed onto the preheated pot surface in six passes, with each application of 50 μm thickness, to form an amorphous alloy coating with a thickness of 200 μm. The plasma arc power was set to 30 kW, the arc current to 700 A, the spray distance to 120 mm, the spray angle to 70°, the powder feed rate to 25 g / min, the hydrogen pressure to 0.5 MPa, and the flow rate to 7 L / min.

[0171] Step (d): Sanding

[0172] The formed amorphous alloy coating was naturally cooled to room temperature, and the surface of the amorphous alloy coating was sanded with 120-grit sandpaper. The sanding process was terminated after confirming that the surface roughness Ra of the amorphous alloy coating reached 1 μm to 2 μm using a roughness meter.

[0173] Surface remelting

[0174] The surface layer of the amorphous alloy coating is irradiated with a laser beam to remelt the surface layer of the amorphous alloy coating, thereby forming a remelted area with a thickness of about 15 μm on the surface of the amorphous alloy coating.

[0175] Thus, the cookware of Comparative Example 11 was finally obtained.

[0176] Comparative Example 12

[0177] The cookware of Comparative Example 12 was manufactured using the same method as Comparative Example 11, except that step (d) of Comparative Example 11 was not performed.

[0178] Comparative Example 13

[0179] The cookware of Comparative Example 13 was manufactured by the same method as Comparative Example 11, except that an amorphous alloy coating with a thickness of 200 μm was formed at one time in step (c) of Comparative Example 11.

[0180] Table 1 Parameters of the Examples and Comparative Examples of the present application

[0181]

[0182]

[0183] Performance index test

[0184] (1) The coatings of the cookware of Examples 1-12 and Comparative Examples 1-13 were subjected to performance tests using the following methods:

[0185] 1. Porosity measurement

[0186] The porosity of the sample is measured using a microscopic measurement method. Specifically, a metallographic microscope at a certain magnification is used to directly observe the surface pores of the sample or to sequentially take parallel cross-sections of the sample to observe its pores, and the porosity is calculated. The porosity is the data obtained by calculating (1-density after thermal spraying / density of raw materials) × 100%. Here, the samples are selected from different areas of the surface coating of the cookware of the embodiment and the comparative example. With respect to the porosity, it is expected that the sample has a porosity of no more than 20%.

[0187] 2. Thermal shock test method

[0188] Heat the coating of the cookware to 450℃ with an open flame and then quickly place it in cold water at room temperature (23+ / -5) to quench it. Observe whether there are any changes in the surface quality of the product, such as peeling or cracking, and record the corresponding number of times as the thermal shock test data. The higher the data, the better the thermal shock performance, and vice versa.

[0189] 3. Adhesion test method

[0190] Measure according to HB 5476 method: Prepare a test specimen of specific size according to the standard requirements and fix it on a tensile testing machine. Stretch it slowly at a speed of 2mm / min until the thermal spray coating breaks, and record the data of the bonding strength between the film layer and the substrate.

[0191] 4. Corrosion resistance test and evaluation standards

[0192] Supor's internal control standard: rust-free after 24 hours of exposure to 5% salt spray. Specifically, according to "6.17 Corrosion Resistance Test Method" in GBT 32432-2015 Household Steel Cookware," a 5% salt solution made from distilled water was placed into the cookware with the sample formed on its inner surface and brought to a boil. The temperature was maintained at a slight boil, and the time it took for rust to appear inside the cookware was recorded. This time served as the corrosion resistance test result and evaluation basis. Here, the sample refers to the coating of the cookware in the Examples and Comparative Examples.

[0193] For the corrosion resistance test, according to the project expectation, the corrosion resistance is not less than 8h.

[0194] Table 2 Performance index test data of the examples and comparative examples of the present application

[0195]

[0196]

[0197] In summary, the present application forms a thermal spray coating by thermal spraying a specific ceramic material, and then remelts the surface of the thermal spray coating to form the surface of the thermal spray coating into a remelting area, thereby manufacturing a cookware, wherein the remelting area serves as the surface layer of the cookware, and has a contact surface for cooking food. The remelting area itself has improved surface hardness, smaller internal pores, and good surface properties, etc. Therefore, using it as the surface layer of the corrosion-resistant coating can better resist erosion by corrosive media, has good corrosion resistance, and can extend the corrosion life of the coating. In addition, the surface roughness of the remelting area is appropriate, and it can be directly used as the surface layer of the cookware (the surface layer refers to the area corresponding to the preset depth inward from the surface of the inner side of the cookware that contacts the food), thereby eliminating the subsequent sanding step. According to the method for manufacturing cookware of the present application, there is no need to precisely control the remelting process, and it is possible to achieve better corrosion resistance than the technical solution of remelting the amorphous alloy coating, and the manufacturing difficulty is greatly reduced. In addition, the appropriate roughness of the cookware surface can reduce friction noise during cooking, ensure that food does not stick, and is easy to clean, thereby providing a good user experience.

[0198] Although the embodiments of the present application have been described in detail above, those skilled in the art may make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. However, it should be understood that, in the opinion of those skilled in the art, such modifications and variations will still fall within the spirit and scope of the embodiments of the present application as defined in the claims.

Claims

1. A method for manufacturing a cookware, characterized in that: The method for manufacturing a cookware comprises: forming a thermal spray coating by thermally spraying ceramic material on a cookware substrate; Remelting the surface layer of the thermal spray coating to form a remelted region, thereby manufacturing a cookware, wherein the remelted region serves as the surface layer of the cookware; Wherein, the ceramic material includes at least one of ferroferric oxide, iron nitride, iron carbide and iron carbide nitride.

2. The method for manufacturing a cookware according to claim 1, wherein: The remelting process adopts an electron beam remelting process.

3. The method for manufacturing a cookware according to claim 2, wherein: The parameters of the electron beam remelting process include: The electron beam power is 25Kev-35Kev; the energy density is 3J·cm 2 -6J·cm 2 ; Pulse duration is 1μS-3μS; vacuum degree is 1×10 -3 Pa-2×10 -3 Pa; the electron beam spot size is 50mm-80mm.

4. The method for manufacturing a cookware according to claim 1, wherein: The remelting treatment of the surface layer of the thermal spray coating includes: Electron beam remelting is performed multiple times on the surface layer of the thermal spray coating.

5. The method for manufacturing a cookware according to claim 1, wherein: The method for manufacturing a cookware does not include the step of sanding the remelted area and / or the thermal sprayed layer.

6. The method for manufacturing a cookware according to claim 1, wherein: The thickness of the thermal spray coating is 30 μm-60 μm; and / or The cookware substrate includes any one of an aluminum substrate, an iron substrate, a magnesium substrate, a copper alloy substrate, an alumina substrate, a stainless steel substrate, a titanium substrate, and a composite substrate formed by the above substrates; and / or The remelted region is formed in a region corresponding to 15 μm to 25 μm inward from the surface of the thermal spray layer.

7. A cookware, characterized in that: The cookware includes a cookware base and a corrosion-resistant coating formed on the surface of the cookware base, wherein the corrosion-resistant coating is formed of at least one of ferroferric oxide, iron nitride, iron carbide and iron carbide nitrogen. The corrosion-resistant coating includes a thermal spraying area and a remelting area stacked on the outside of the thermal spraying area, and the remelting area serves as the surface layer of the cookware.

8. The cookware according to claim 7, characterized in that: The remelting area is formed at an area corresponding to a preset value inward from the surface of the corrosion-resistant coating, and the preset value is 1 / 3-1 / 2 of the thickness of the corrosion-resistant coating.

9. The cookware according to claim 8, characterized in that: The thickness of the corrosion-resistant coating is 30 μm-60 μm, and the preset value is 15 μm-25 μm.

10. The cookware according to claim 7, characterized in that: The porosity of the remelted region is 0.3%-0.5%, and the pore size is 5μm-10μm; and / or the hardness of the remelted region is 1200HV-1750HV; and / or the surface roughness of the remelted region is 0.5μm-3μm.

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