Coated multilayer metal cooking carrier heatable by induction

Abstract

The invention relates to a coated multilayer metal cooking carrier compatible with induction heating, comprising a metal body comprising a heating surface (120) with a protective coating and a cooking surface with a non-stick coating forming the cooking surface, the metal body comprising an aluminum sheet metallurgically assembled with a double-sided aluminized low-carbon ferromagnetic steel sheet forming the heating surface (120), the double-sided aluminized low-carbon ferromagnetic steel sheet comprises a low-carbon steel ferromagnetic substrate (111) having, on each of the two faces thereof, an outer layer (112) comprising an aluminum-based matrix, an intermediate layer comprising an iron / aluminum intermetallic compound being provided between the low-carbon steel ferromagnetic substrate (111) and the outer layer (112) and at least on the bottom of the heating face (120), the outer layer (112) having a thickness of less than 27 [mu] m, and the intermediate layer (112) having a thickness of less than 30 [mu] m. Preferably less than 20 [mu] m, more preferably less than 18 [mu] m. The invention also relates to a cookware, an electric cooking appliance and a method for obtaining a coated metal cooking carrier.

Description

[0001] Related Applications

[0002] This invention is a divisional application of a patent application with an application date of December 22, 2020, application number 202080090289.4, and invention name “Coated multi-layer metal cooking carrier capable of being heated by induction”. Technical Field

[0003] The present invention relates to the technical field of metal cooking carriers compatible with induction heating for cooking or heating food. Such metal cooking carriers can be used with induction heating devices, such as induction cookers placed on or integrated into worktops, or induction heating ovens integrated into electric cooking devices.

[0004] The present invention more particularly relates to coated multi-layer metal cooking supports that are compatible with induction heating.

[0005] The present invention relates particularly, but not exclusively, to a coated multi-layer metal cooking support forming a cooking vessel.

[0006] The present invention also relates to a cookware comprising a coated multi-layer metal cooking carrier associated with at least one gripping member.If desired, one or more gripping members may be removable or detachable relative to the coated multi-layer metal cooking carrier.

[0007] The invention also relates to an electric cooking device comprising a multi-layer coated metal cooking carrier associated with induction heating means. Background Art

[0008] From document EP 2 554 080 it is known to produce coated cookware compatible with induction heating, in which the metal plates forming the cooking surface are assembled with ferritic stainless steel plates by using an intermediate aluminum plate to obtain a metallurgical assembly of the various plates.

[0009] A disadvantage of this type of realization is that such a coated metal cooking support has a relatively high cost price, in particular due to the presence of a stamping operation to obtain the metallurgical assembly of the various plates.

[0010] Another disadvantage of this type of implementation is that, due to the presence of the intermediate aluminum plate and the ferritic stainless steel plate, such a coated metal cooking support is relatively heavy. Summary of the invention

[0011] Various aspects of the present invention are directed to overcoming the disadvantages of the prior art by providing a coated multi-layer metal cooking carrier that is compatible with induction heating and has a limited cost price.

[0012] A first aspect of the invention relates to a coated multilayer metal cooking support compatible with induction heating, comprising a metal body comprising a heating surface and a cooking surface, the heating surface having a bottom configured to rest on an induction heating device, the heating surface being provided with a protective coating, the cooking surface being provided with a non-stick coating forming a cooking surface, wherein the metal body comprises an aluminum plate metallurgically assembled with a double-sided aluminum-coated low-carbon ferromagnetic steel plate forming the heating surface, and optionally with another double-sided aluminum-coated low-carbon ferromagnetic steel plate metallurgically assembled, wherein the double-sided aluminum-coated low-carbon ferromagnetic steel plate comprises a low-carbon steel magnetic substrate having an outer layer comprising an aluminum-based matrix on each of its two faces, wherein an intermediate layer comprising an iron / aluminum intermetallic compound is arranged between the low-carbon steel magnetic substrate and the outer layer, and wherein the outer layer has a thickness of less than 27 μm, preferably less than 20 μm, more preferably less than 18 μm at least on the bottom of the heating surface. The low-carbon steel used for the ferromagnetic substrate is sensitive to magnetic fields and can be inductively heated. In contrast, aluminum is an interfering material for magnetic fields used for induction heating. However, during the aluminizing of steel sheets, an intermetallic reaction layer is formed at the interface between steel and aluminum. The intermetallic compound of the intermediate layer does not have the interfering properties of aluminum with respect to the magnetic field used for induction heating. Therefore, in the aluminum-based coating used for aluminizing, the thickness of the outer layer comprising the aluminum-based matrix appears to be the main relevant parameter for obtaining compatibility with induction cookers. The use of such a coated metal body makes it possible to obtain a coated multilayer metal cooking carrier compatible with induction heating, which is more economical to realize than a coated metal cooking carrier comprising an aluminum body associated with a ferromagnetic steel element. The use of such a coated metal body makes it possible to obtain a coated multilayer metal cooking carrier compatible with induction heating, which is lighter than a coated metal cooking carrier made of cast steel. The aluminum sheet makes it possible to limit hot spots and thus limit the risk of overheating of the non-stick coating forming the cooking surface.

[0013] The outer layer may comprise Al-Fe-Si needles in an aluminium-silicon matrix. The use of an aluminising bath comprising aluminium and silicon is advantageous in producing the outer layer during aluminising of the steel sheet. Silicon does not have the disruptive properties of aluminium for the magnetic field used for induction heating.

[0014] The thickness of the mild steel magnetic substrate may be between 0.3 and 1 mm, preferably between 0.3 and 0.5 mm, and the thickness of the aluminum plate may be between 0.3 and 3 mm, preferably between 0.5 and 1.5 mm.

[0015] The low carbon steel magnetic substrate may be produced from a steel grade containing up to 0.3 mass % carbon, preferably 0.1 to 0.2 mass % carbon.

[0016] The protective coating can be implemented directly on the heating surface of the metal body. The protective coating can include one or more layers.

[0017] The non-stick coating can be implemented directly on the cooking surface of the metal body. The non-stick coating can include one or more layers. If necessary, an intermediate coating can be provided between the non-stick coating and the metal body to obtain a hard substrate.

[0018] The protective coating may in particular be a PTFE-type coating, or an enamel-type coating, or a lacquer-type coating, or a ceramic-type coating, or a sol-gel-type coating.

[0019] According to one embodiment, the protective coating can be a PTFE type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating, and the metal body comprises an aluminum-based deposit having a thickness of less than 30 μm, preferably less than 20 μm, at least on the bottom of the heating surface.

[0020] According to another embodiment, the protective coating may be a coating of the enamel type, the metal body comprising an aluminum-based deposit having a thickness of less than 40 μm, preferably less than 30 μm, at least on the bottom of the heating face.

[0021] The non-stick coating may be a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

[0022] The coated multi-layer metal cooking carrier may have a bottom raised around the heating surface to form the side walls of the cooking vessel.

[0023] The coated multi-layer metal cooking support can in particular have a flange or a curled edge or an open curled edge. These arrangements allow to avoid exposing the cut edges of the metal body.

[0024] A second aspect of the present invention relates to a cookware comprising a coated multi-layer metal cooking carrier and a gripping member mounted on the coated multi-layer metal cooking carrier, wherein the coated multi-layer metal cooking carrier complies with at least one of the above-mentioned features.

[0025] A third aspect of the invention relates to an electric cooking device comprising a coated multi-layer metal cooking carrier associated with an induction heating oven, wherein the coated multi-layer metal cooking carrier complies with at least one of the above-mentioned characteristics.

[0026] A fourth aspect of the invention relates to a method for obtaining a coated multilayer metal cooking support compatible with induction heating according to at least one of the above characteristics, comprising the following steps:

[0027] - cutting or providing a multilayered formed part from a double-sided aluminized low-carbon ferromagnetic steel sheet metallurgically assembled with an aluminum sheet, the double-sided aluminized low-carbon ferromagnetic steel sheet having a first free face, the aluminum sheet having a second free face,

[0028] - stamping the multilayer formed part to form a metal body comprising a heating surface corresponding to the first free surface and a cooking surface corresponding to the second free surface,

[0029] -Produce a protective coating on the heating surface,

[0030] - Make a non-stick coating on the cooking surface to create a cooking surface.

[0031] A fifth aspect of the invention relates to a method for obtaining a coated multilayer metal cooking support compatible with induction heating according to at least one of the above characteristics, comprising the following steps:

[0032] - cutting or providing a multilayered formed part from an aluminium sheet metallurgically assembled with a double-sided aluminium-clad low-carbon ferromagnetic steel sheet, where appropriate with another double-sided aluminium-clad low-carbon ferromagnetic steel sheet having a first free face and another double-sided aluminium-clad low-carbon ferromagnetic steel sheet having a second free face,

[0033] - stamping the multilayer formed part to form a metal body comprising a heating surface corresponding to the first free surface and a cooking surface corresponding to the second free surface,

[0034] -Produce a protective coating on the heating surface,

[0035] - Make a non-stick coating on the cooking surface to create a cooking surface.

[0036] According to one or other of these aspects, after stamping the multilayer form and before applying the protective coating and the non-stick coating, the method may include the step of treating the peripheral portion of the multilayer form to obtain a flange or a curled edge or an open curled edge.

[0037] The protective coating may in particular be a PTFE-type coating, or an enamel-type coating, or a lacquer-type coating, or a ceramic-type coating, or a sol-gel-type coating.

[0038] The non-stick coating may in particular be a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

[0039] A sixth aspect of the invention relates to a method for obtaining a coated multilayer metal cooking support compatible with induction heating according to at least one of the above characteristics, comprising the following steps:

[0040] - cutting or providing a multilayered formed part from an aluminium sheet metallurgically assembled with a double-sided aluminium coated low carbon ferromagnetic steel sheet having a first free face and with another double-sided aluminium coated low carbon ferromagnetic steel sheet having a second free face,

[0041] - producing a protective coating on a first free face and a non-stick coating on a second free face to obtain a coated multilayer shaped part,

[0042] - Stamping the coated multilayer form to form a coated metal body comprising a heating surface with a protective coating and a cooking surface with a non-stick coating to form a cooking surface.

[0043] After making the protective coating and the non-stick coating and after stamping of the coated multilayer form, the method may comprise the step of treating the peripheral portion of the coated multilayer form to obtain a flange or a curled edge or an open curled edge.

[0044] The protective coating may in particular be a PTFE-type coating or a lacquer-type coating.

[0045] The non-stick coating may be a PTFE type coating.

[0046] According to one embodiment, the multilayer shaped part can be a disc. However, other shapes are also conceivable. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Other characteristics and properties of the invention will become more apparent from a reading of the following detailed description of in no way limiting embodiments and variants illustrated in the accompanying drawings, in which:

[0048] Figure 1 A partial schematic diagram showing one embodiment of a metal body for making a coated metal cooking carrier,

[0049] Figure 2 express Figure 1 An enlarged cross-sectional schematic diagram of the metal body shown in FIG.

[0050] Figure 3 express Figure 2 An enlarged cross-sectional view of a surface portion of a metal body shown in FIG.

[0051] Figure 4 yes Figure 1 The enlarged cross-sectional view of the metal body shown in FIG. 1 after the protective coating and the non-stick coating are applied,

[0052] Figure 5 A partial schematic diagram showing an embodiment of a metal body for making a multi-layer coated metal cooking carrier according to the present invention,

[0053] Figure 6 express Figure 5 The schematic cross-sectional view of the metal body shown in FIG. 1 after the protective coating and the non-stick coating are applied.

[0054] Figure 7A partial schematic diagram showing another embodiment of a metal body for making a multi-layer coated metal cooking carrier according to the present invention,

[0055] Figure 8 express Figure 7 The schematic cross-sectional view of the metal body shown in FIG. 1 after the protective coating and the non-stick coating are applied.

[0056] Fig. 9 Meaning according to the present invention includes Figure 6 or Figure 8 A schematic cross-sectional view of an embodiment of a metal cooking carrier coated with multiple layers of a metal body as shown in FIG.

[0057] Fig.10 A schematic cross-sectional view showing a first variant embodiment of the peripheral portion of a coated multi-layer metal cooking support with a turned edge according to the present invention,

[0058] Fig.11 A schematic cross-sectional view showing a second variant embodiment of the peripheral portion of a coated multilayer metal cooking support with a curled edge according to the present invention,

[0059] Fig.12 A schematic cross-sectional view showing a third variant embodiment of a peripheral portion of a coated multilayer metal cooking support with an open curled edge according to the present invention,

[0060] Fig.13 Schematic diagrams in front and vertical section showing an embodiment of a cooker comprising a coated multi-layer metal cooking carrier according to the present invention,

[0061] Fig.14 Schematic elevation and vertical section views show an embodiment of an electric cooking device comprising a coated multi-layer metal cooking carrier according to the invention. DETAILED DESCRIPTION

[0062] Figure 1 An embodiment of a metal body 110 is shown for implementing a coated metal cooking carrier that is compatible with induction heating.

[0063] The metal body 110 is made of a double-sided aluminum-plated low-carbon ferromagnetic steel sheet 101. The double-sided aluminum plating of the low-carbon ferromagnetic steel sheet is obtained by immersion in an aluminum-based aluminum plating bath to produce an aluminum-based deposit 115. The aluminum-based bath may include silicon, in particular 8 to 13% by mass of silicon, to facilitate deposition on the steel. In particular, an aluminum-silicon alloy of the AS type may be used, such as an AS alloy containing 8 to 13% by mass of silicon. However, it is conceivable to use an aluminum plating bath with a lower silicon proportion or an aluminum plating bath without silicon. The amount of material deposited on the steel sheet can be evaluated by weighing. The additional mass thus obtained makes it possible to define the thickness of the aluminum-based deposit 115 on the steel sheet. Typically, such an aluminum-based deposit 115 can reach several tens of μm.

[0064] like Figure 2 As shown, a double-sided aluminized low carbon ferromagnetic steel sheet 101 for achieving a coated metal cooking carrier compatible with induction heating comprises a low carbon steel ferromagnetic base plate 111 having an aluminum-based outer layer 112 on each of its two sides.

[0065] The low carbon steel magnetic substrate 111 may have a thickness of 0.7 to 3 mm, in particular a thickness of 1 to 2 mm. The low carbon steel magnetic substrate 111 material is selected to be compatible with induction heating. The low carbon steel magnetic substrate 111 may be made of a steel grade containing up to 0.3 mass % carbon, preferably 0.1 to 0.2 mass % carbon. The low carbon steel magnetic substrate 111 may be produced in particular with DX51 to DX56 grades, which include 0.12 mass % to 0.18 mass % carbon and up to 0.5 mass % silicon.

[0066] like Figure 3 It can be clearly seen that the intermediate layer 113 is arranged between the mild steel magnetic substrate 111 and the outer layer 112. The intermediate layer 113 is an intermetallic reaction layer, comprising iron / aluminum intermetallic compounds, in particular FeAl3 and Fe2Al5. Therefore, all the aluminum-based deposits 115 made on the steel plate are not present in the outer layer 112. Part of the aluminum-based deposits 115 are present in the intermediate layer 113.

[0067] The thickness of the intermediate layer 113 is generally 3 to 5 μm. However, heat treatment over 500° C. may help increase the thickness of the intermediate layer 113 at the expense of the thickness of the outer layer 112, so the intermediate layer 113 may be subdivided into a plurality of sublayers with different aluminum / iron ratios, which increase from the low carbon steel magnetic substrate 111 to the outer layer 112.

[0068] When the aluminum plating bath includes silicon, the aluminum-based outer layer 112 may include silicon, particularly 8 to 13 mass % silicon. Thus, the outer layer 112 may include Al-Fe-Si needles 114 in an aluminum-silicon matrix 116, such as Figure 4 This can be seen in the embodiment shown.

[0069] Figure 5 and Figure 6 Two embodiments of the metal body 110 are described. The metal body 110 is used to make Fig. 9 A coated multi-layer metal cooking carrier 100 compatible with induction heating is shown in FIG.

[0070] Figure 5 The metal body 110 shown is Figure 1The metal body 110 shown is different in that it includes an aluminum plate 102 metallurgically assembled with a double-sided aluminum-plated low-carbon ferromagnetic steel plate 101. The aluminum plate 102 is made of a forged aluminum alloy. The cladding of the aluminum plate 102 metallurgically assembled with the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 can be performed, for example, by rolling or by diffusion. The thickness of the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 is, for example, 0.3 to 1 mm, preferably 0.3 to 0.5 mm. The thickness of the aluminum plate 102 is, for example, 0.3 to 3 mm, preferably 0.5 to 1.5 mm.

[0071] Figure 6 The metal body 110 shown is Figure 5 The metal body 110 shown is different in that it includes another double-sided aluminum-plated low-carbon ferromagnetic steel plate 103 metallurgically assembled with the aluminum plate 102. The cladding of the aluminum plate 102 metallurgically assembled with the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 and with the other double-sided aluminum-plated low-carbon ferromagnetic steel plate 103 can be performed, for example, by rolling or by diffusion. The thickness of the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 is, for example, 0.3 to 1 mm, preferably 0.3 to 0.5 mm. The thickness of the aluminum plate 102 is, for example, 0.3 to 3 mm, preferably 0.5 to 1.5 mm. The thickness of the other double-sided aluminum-plated low-carbon ferromagnetic steel plate 103 is, for example, 0.3 to 1 mm, preferably 0.3 to 0.5 mm.

[0072] like Fig. 9 As shown, the metal body 110 includes a heating surface 120 and a cooking surface 130. The heating surface 120 has a bottom 122 configured to be placed on an induction heating device, in particular, on an induction cooker or an induction heating stove.

[0073] like Fig. 9 As shown, the heating surface 120 has a protective coating 121 ; the cooking surface 130 has a non-stick coating 131 forming a cooking surface 132 .

[0074] Figure 6 or Figure 8 The illustrated coated multi-layer metal cooking carrier 100 compatible with induction heating according to the present invention comprises a metal body 110, a protective coating 121 and a non-stick coating 131. The metal body 110 carries the protective coating 121 and the non-stick coating 131.

[0075] exist Figure 1 Examples and Figure 5 and Figure 6 In the embodiment, the heating surface 120 is formed by a double-sided aluminum-plated low-carbon ferromagnetic steel plate 101.

[0076] exist Figure 6In the embodiment of the present invention, the cooking surface 130 is formed by an aluminum plate 102. The thickness of the aluminum plate 102 is, for example, about 1.2 mm, and the thickness of the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 is, for example, about 0.3 mm.

[0077] exist Figure 8 In the embodiment of the present invention, the cooking surface 130 is formed by another double-sided aluminum-plated low-carbon ferromagnetic steel plate 103. The thickness of the aluminum plate 102 is, for example, about 1.2 mm, and the thickness of the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 and the other double-sided aluminum-plated low-carbon ferromagnetic steel plate 103 is, for example, about 0.3 mm.

[0078] If necessary, the protective coating 121 can be implemented directly on the heating surface 120 of the metal body 110, in particular on the outer layer 112 on the side of the bottom 122. If necessary, the surface of the heating surface 120 can be prepared before making the protective coating 121. The protective coating 121 can be in particular a PTFE type coating, or an enamel type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating.

[0079] If desired, the non-stick coating 131 can be implemented directly on the cooking surface 130 of the metal body 110. If desired, the cooking surface 130 can be surface prepared before implementing the protective coating 121. The non-stick coating 131 can in particular be a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

[0080] like Fig. 9 As shown, the coated multilayer metal cooking carrier 100 may include a side wall 123 that rises around a bottom 122 of a heating surface 120 to form a cooking container 124. As a variant, the coated multilayer metal cooking carrier 100 does not necessarily form a cooking container 124. The coated multilayer metal cooking carrier 100 may in particular form a cooking plate.

[0081] Tests conducted with multiple induction cookers showed that the relevant parameter for obtaining induction heating compatibility on different induction heating devices is the thickness of the outer layer 112 on the bottom 122 of the heating surface 120, rather than the thickness of the aluminum-based deposit 115 on the bottom 122 of the heating surface 120. The induction cookers used are described in Table 1.

[0082] [Table 1]

[0083]

[0084] In fact, these tests have shown that when the protective coating 121 is a PTFE type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating, in order to obtain coupling on an induction cooker, the limit value of the thickness of the aluminum-based deposit 115 on the bottom 122 of the heating surface 120 is about 30 μm, but when the protective coating 121 is an enamel type coating, in order to obtain coupling on an induction cooker, the limit value of the thickness of the aluminum-based deposit 115 on the bottom 122 of the heating surface 120 is about 40 μm. These tests also show that satisfactory coupling is obtained with all induction cookers when the thickness of the aluminum-based deposit 115 on the bottom 122 of the heating surface 120 is less than about 20 μm when the protective coating 121 is a coating of the PTFE type, or a coating of the lacquer type, or a coating of the ceramic type, or a coating of the sol-gel type, and satisfactory coupling is obtained with all induction cookers when the thickness of the aluminum-based deposit 115 on the bottom 122 of the heating surface 120 is less than about 30 μm when the protective coating 121 is a coating of the enamel type. The use of enamel-type coatings requires firing temperatures of about 550° C. to 600° C. However, above 500° C., the diffusion phenomena occurring at the steel / aluminum interface favor the formation of an iron / aluminum intermetallic compound, which moves the interface between the intermediate layer 113 and the outer layer 112 and reduces the thickness of the outer layer 112.

[0085] The thickness of the intermediate layer 113 is typically about 3 to 5 μm, but may be greater, in particular if the heat treatment favours an increase in thickness of the intermediate layer 113 (in the form of a plurality of sub-layers where appropriate) and / or a reduction in thickness of the outer layer 112 .

[0086] The thickness of the outer layer 112 on the bottom 122 of the heating surface 120 is decisive for the compatibility of the coated multilayer metal cooking carrier 100 with inductive heating. For the outer layer 112 on the bottom 122 of the heating surface 120, a thickness of less than 27 μm is considered to be the limit value for obtaining coupling on an induction cooker. For the outer layer 112 on the bottom 122 of the heating surface 120, a thickness of less than 26 μm gives better results than a thickness of less than 27 μm, a thickness of less than 25 μm gives better results than a thickness of less than 26 μm, a thickness of less than 24 μm gives better results than a thickness of less than 25 μm, a thickness of less than 23 μm gives better results than a thickness of less than 24 μm, a thickness of less than 22 μm gives better results than a thickness of less than 23 μm, a thickness of less than 21 μm gives better results than a thickness of less than 22 μm, a thickness of less than 20 μm gives better results than a thickness of less than 21 μm, a thickness of less than 19 μm gives better results than a thickness of less than 20 μm, a thickness of less than 18 μm gives better results than a thickness of less than 19 μm, and a thickness of less than 17 μm gives better results than a thickness of less than 18 μm. For the outer layer 112 on the bottom 122 of the heating surface 120, a thickness of less than 20 μm allows a sufficiently satisfactory coupling to the induction cooker. For the outer layer 112 on the bottom 122 of the heating surface 120, a thickness of less than 18 μm allows a very satisfactory coupling with an induction cooker. The efficiency (power absorbed by the multi-layer coated metal cooking carrier 100 / power emitted by the induction cooker) can be close to 100%. The heating speed is very fast.

[0087] like Fig. 9 As shown, the coated multi-layer metal cooking carrier 100 compatible with induction heating has an exposed cut edge 128. The cut edge 128 is generally free of the outer layer 112, which is due to cutting the metal body 110 to produce a coated form suitable for making the coated multi-layer metal cooking carrier 100. The cut edge 128 can be at least partially covered by the protective coating 121 and / or the non-stick coating 131. Preferably, the exposed cut edge 128 is covered by the protective coating 121 and / or the non-stick coating 131.

[0088] like Fig.10 As shown, the coated multi-layer metal cooking carrier 100 compatible with induction heating may have a flange 125. Fig.11 As shown, the induction heating compatible coated multi-layer metal cooking carrier 100 may have a rolled edge 126. Fig.12 As shown, the coated multi-layer metal cooking carrier 100 compatible with induction heating may have an open rolled edge 127. Thus, the cut edge 128 does not appear on the upper surface of the coated multi-layer metal cooking carrier 100.

[0089] Fig.13The cookware 140 is shown, which includes a coated multi-layer metal cooking carrier 100 and a gripping member 150 mounted on the coated multi-layer metal cooking carrier 100. The coated multi-layer metal cooking carrier 100 forms Fig. 9 The cooking container 124 is shown. Fig. 9 In the illustrated embodiment, the gripping member 150 is fixed to the cooking container 124 by at least one rivet 151. For this purpose, the rivet 151 is installed in a hole provided on the side wall 123. If desired, a plurality of rivets 151 may be used to fix the gripping member 150 to the cooking container 124. Preferably, two to four rivets 151 are used to fix the gripping member 150 to the cooking container 124. Alternatively, the gripping member 150 may be fixed to the side wall 123 by welding or by screwing to a stud welded to the side wall 123. If desired, another gripping member may be fixed to the side wall 123 of the cooking container 124 by at least another rivet, by welding or by screwing to a stud welded to the side wall 123.

[0090] Fig.14 An electric cooking device 160 is shown that includes a coated multi-layer metal cooking carrier 100 associated with an induction heating oven 170. The coated multi-layer metal cooking carrier 100 forms Fig. 9 The cooking container 124 is shown. The cooking container 124 is arranged in a heating base 175 including an induction heating furnace 170. The bottom 122 rests on the induction heating furnace 170. If desired, the cooking container 124 may include at least one gripping member 155. Fig.14 In the illustrated embodiment, the cooking container 124 comprises two opposing gripping members 155. The gripping member or each gripping member 155 is fixed to the cooking container 124 by at least one rivet 156. For this purpose, the rivet 156 is installed in a hole provided on the side wall 123. If desired, a plurality of rivets 156 may be used to fix the gripping member or each gripping member 155 to the cooking container 124. Preferably, two to four rivets 156 are used to fix the gripping member or each gripping member 155 to the cooking container 124. Alternatively, the gripping member or at least one gripping member 155 may be fixed to the side wall 123 by welding or by screwing to a stud welded to the side wall 123.

[0091] The coated multi-layered metal cooking carrier 100 compatible with induction heating according to the present invention can be obtained by different methods.

[0092] A first method for obtaining a coated multi-layer metal cooking carrier 100 compatible with induction heating comprises the following steps:

[0093] - cutting or providing a multilayered formed part from a double-sided aluminized low-carbon ferromagnetic steel sheet 101 metallurgically assembled with an aluminum sheet 102, the double-sided aluminized low-carbon ferromagnetic steel sheet 101 having a first free face, the aluminum sheet 102 having a second free face,

[0094] - stamping the multilayered formed part to form a metal body 110 comprising a heating face 120 corresponding to a first free face and a cooking face 130 corresponding to a second free face,

[0095] - making a protective coating 121 on the heating surface 120,

[0096] - Producing a non-stick coating 131 on the cooking surface 130 to form a cooking surface 132 .

[0097] A second method for obtaining a coated multi-layer metal cooking carrier 100 compatible with induction heating comprises the following steps:

[0098] - cutting or providing a multilayered formed part from an aluminium sheet 102 metallurgically assembled with a double-sided aluminium-coated low-carbon ferromagnetic steel sheet 101 having a first free face and with another double-sided aluminium-coated low-carbon ferromagnetic steel sheet 103 having a second free face,

[0099] - stamping the multilayered formed part to form a metal body 110 comprising a heating face 120 corresponding to a first free face and a cooking face 130 corresponding to a second free face,

[0100] - Making a protective coating 121 on the heating surface 120,

[0101] A non-stick coating 131 is made on the cooking surface 130 to form a cooking surface 132 .

[0102] The multilayer shaped part can be in particular a disc. If desired, after stamping the multilayer shaped part and before making the protective coating 121 and the non-stick coating 131, the first method or the second method can include a processing step of the peripheral portion of the multilayer shaped part to obtain a flange 125 or a curling 126 or an open curling 127.

[0103] In the first method or in the second method, the protective coating 121 and the non-stick coating 131 are produced after the forming operation. A wide range of coatings can be used. The protective coating 121 can be in particular a PTFE type coating, or an enamel type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating. The non-stick coating 131 can be in particular a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

[0104] A third method for obtaining a coated multi-layer metal cooking carrier 100 compatible with induction heating comprises the following steps:

[0105] - cutting or providing a multilayered formed part from an aluminium sheet metallurgically assembled with a double-sided aluminium-coated low-carbon ferromagnetic steel sheet 101 having a first free face and with another double-sided aluminium-coated low-carbon ferromagnetic steel sheet 103 having a second free face,

[0106] - making a protective coating 121 on a first free face and a non-stick coating 131 on a second free face, so as to obtain a coated multilayer shaped part,

[0107] - Stamping the coated multilayer form to form a coated metal body 110 comprising a heating face 120 with a protective coating 121 and a cooking face 130 with a non-stick coating 131 to form a cooking surface 132 .

[0108] The multilayer shaped part can be in particular a disc. If desired, after making the protective coating 121 and the non-stick coating 131 and after the stamping of the multilayer shaped part, the third method may comprise a treatment step of the peripheral portion of the shaped part to obtain a flange 125 or a curling 126 or an open curling 127.

[0109] In this third method, the protective coating 121 and the non-stick coating 131 are made before the forming operation. Therefore, the range of coatings that can be used is more limited. The protective coating 121 and the non-stick coating 131 must allow for forming by stamping of the formed part. The protective coating 121 can in particular be a PTFE type coating or a lacquer type coating. The non-stick coating 131 can in particular be a PTFE type coating.

[0110] The use of a metal body 110 comprising a double-sided aluminized low-carbon ferromagnetic steel sheet 101 on one side thereof to produce the coated multi-layer metal cooking carrier 100 allows the use of conventional manufacturing processes, which limits the necessary investment.

[0111] The coated multilayer metal cooking carrier 100 is mechanically very strong. The efficiency (power absorbed / power emitted by the induction heating device) is very high, especially if the thickness of the aluminum-based deposit 115 is less than 20 μm. The heating speed is fast: about 15 seconds for a pan with a diameter of 28 cm, while about 1 minute and 30 seconds for a standard pan of the same diameter made of aluminum, which includes a stainless steel insert to be compatible with induction heating. Energy savings can be achieved, because the power provided by the induction heating device can be lower.

[0112] Adoption basis Figure 6 The two-layer structure of the embodiment or according to Figure 8The three-layer construction of the embodiment, the presence of the aluminum plate 102 metallurgically assembled with the double-sided aluminum-plated low-carbon ferromagnetic steel plate 101 makes it possible to improve the thermal uniformity of the cooking surface 132.

[0113] Adoption basis Figure 6 The two-layer construction of the embodiment, multi-layer coated metal cooking carrier 100 remains fairly light while providing better thermal uniformity.

[0114] Adoption basis Figure 8 The three-layer construction of the embodiment, the presence of another double-sided aluminized low-carbon ferromagnetic steel plate 103 metallurgically assembled with the aluminum plate 102 makes it possible to use a process in which the forming is performed after the coating operation. The coated multi-layer metal cooking carrier 100 remains relatively light.

[0115] Various modifications and / or improvements that are obvious to a person skilled in the art may be made to the embodiments of the invention described in this specification without departing from the scope of the invention as defined by the appended claims.

Claims

1. A coated multi-layer metal cooking carrier (100) compatible with induction heating, comprising a metal body (110), the metal body (110) comprising a heating surface (120) and a cooking surface (130), the heating surface (120) having a bottom (122) configured to rest on an induction heating device, characterized in that: The metal body (110) comprises an aluminum plate (102) metallurgically assembled with a double-sided aluminum-plated low-carbon ferromagnetic steel plate (101) forming a heating surface (120) and, if necessary, with another double-sided aluminum-plated low-carbon ferromagnetic steel plate (103), the double-sided aluminum-plated low-carbon ferromagnetic steel plate (101) comprising a low-carbon steel magnetic substrate (111), the low-carbon steel magnetic substrate having an outer layer (112) containing an aluminum-based matrix on each of its two faces, an intermediate layer (113) containing an iron / aluminum intermetallic compound disposed between the low-carbon steel magnetic substrate (111) and the outer layer (112), the heating surface (120) having a protective coating (121), and the metal body (110) comprises an aluminum-based deposit (115), the aluminum-based deposit (115) having a thickness of less than 40 μm at least on the bottom (122) of the heating surface (120), the cooking surface (130) having a non-stick coating (131) forming the cooking surface (132), the intermediate layer (113) being formed by an iron / aluminum intermetallic compound having no interference properties with respect to a magnetic field, and the metal body (110) being subjected to a heat treatment exceeding 500° C. so that the thickness of the intermediate layer (113) is greater than 5 μm and at least on the bottom (122) of the heating surface (120), the outer layer (112) having a thickness of less than 27 μm.

2. The induction heating compatible coated multi-layer metal cooking carrier (100) according to claim 1, characterized in that: The outer layer (112) comprises Al-Fe-Si needles in an aluminum-silicon matrix, the outer layer (112) particularly comprising 8 to 13% by mass of silicon.

3. The coated multi-layer metal cooking carrier (100) compatible with induction heating according to any one of claims 1 or 2, characterized in that: The thickness of the low carbon steel magnetic substrate (111) is between 0.3 and 1 mm, preferably between 0.3 and 0.5 mm, and the thickness of the aluminum plate (102) is between 0.3 and 3 mm, preferably between 0.5 and 1.5 mm.

4. The coated multi-layer metal cooking carrier (100) compatible with induction heating according to any one of claims 1 or 2, characterized in that: The low carbon steel magnetic substrate (111) is made of a steel grade containing up to 0.3 mass % carbon, preferably 0.1 to 0.2 mass % carbon.

5. The induction heating compatible coated multi-layer metal cooking carrier (100) according to any one of claims 1 or 2, characterized in that: The protective coating (121) is implemented directly on the heating surface (120) of the metal body (110).

6. The coated multi-layer metal cooking carrier (100) compatible with induction heating according to any one of claims 1 or 2, characterized in that: The protective coating (121) is a PTFE type coating, or an enamel type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating.

7. The induction heating compatible coated multi-layer metal cooking carrier (100) according to claim 6, characterized in that: The protective coating (121) is a PTFE type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating, and the aluminum-based deposit (115) has a thickness of less than 30 μm, preferably less than 20 μm, at least on the bottom (122) of the heating surface (120).

8. The induction heating compatible coated multi-layer metal cooking carrier (100) according to claim 6, characterized in that: The protective coating (121) is an enamel-type coating and the aluminum-based deposit (115) has a thickness of preferably less than 30 μm at least on the bottom (122) of the heating surface (120).

9. The induction heating compatible coated multi-layer metal cooking carrier (100) according to any one of claims 1 or 2, characterized in that: The non-stick coating (131) is a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

10. The induction heating compatible coated multi-layer metal cooking carrier (100) according to any one of claims 1 or 2, characterized in that: The side walls (123) rise around the bottom (122) of the heating surface (120) to form a cooking container (124).

11. The induction heating compatible coated multi-layer metal cooking carrier (100) according to any one of claims 1 or 2, characterized in that: The coated multi-layer metal cooking support has a flange (125) or a curled edge (126) or an open curled edge (127).

12. The induction heating compatible coated multi-layer metal cooking carrier (100) according to claim 1, characterized in that: At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 20 μm.

13. The induction heating compatible coated multi-layer metal cooking carrier (100) according to claim 1, characterized in that: At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 18 μm.

14. A cooker (140) comprising a multi-layer coated metal cooking carrier (100) and a gripping member (150) mounted on the multi-layer coated metal cooking carrier (100), characterized in that: The coated multi-layer metal cooking carrier (100) complies with any one of claims 1 to 13.

15. An electric cooking device (160) comprising a coated multi-layer metal cooking carrier (100) associated with an induction heating oven (170), characterized in that The coated multi-layer metal cooking carrier (100) complies with any one of claims 1 to 13.

16. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 1 to 13, comprising the following steps: - cutting or providing a multilayered formed part from a double-sided aluminized low-carbon ferromagnetic steel sheet (101) metallurgically assembled with an aluminum sheet (102), the double-sided aluminized low-carbon ferromagnetic steel sheet (101) having a first free face, the aluminum sheet (102) having a second free face, - stamping the multilayer formed part to form a metal body (110) comprising a heating surface (120) corresponding to a first free surface and a cooking surface (130) corresponding to a second free surface, The double-sided aluminum-plated low-carbon ferromagnetic steel plate (101) comprises a low-carbon steel magnetic substrate (111), wherein the low-carbon steel magnetic substrate has an outer layer (112) containing an aluminum-based matrix on each of its two surfaces, and an intermediate layer (113) containing an iron / aluminum intermetallic compound is arranged between the low-carbon steel magnetic substrate (111) and the outer layer (112), wherein the intermediate layer (113) is formed of an iron / aluminum intermetallic compound that does not have interference characteristics with respect to a magnetic field, and the metal body (110) is subjected to a heat treatment exceeding 500° C., so that the thickness of the intermediate layer (113) is greater than 5 μm and at least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 27 μm, - implementing a protective coating (121) on the heating surface (120), - A non-stick coating (131) is implemented on the cooking surface (130) to form a cooking surface (132).

17. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 16, characterized in that After stamping of the multilayer formed part and before applying the protective coating (121) and the non-stick coating (131), the method comprises a step of treating the peripheral portion of the multilayer formed part to obtain a flange (125) or a curled edge (126) or an open curled edge (127).

18. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 16 or 17, characterized in that The protective coating (121) is a PTFE type coating, or an enamel type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating.

19. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 16 or 17, characterized in that The non-stick coating (131) is a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

20. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 16 or 17, characterized in that The multi-layered formed part is a disc.

21. The method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 16, characterized in that At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 20 μm.

22. The method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 16, characterized in that At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 18 μm.

23. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 1 to 13, comprising the following steps: - cutting or providing a multilayer formed part from an aluminium sheet (102) metallurgically assembled with a double-sided aluminium-coated low-carbon ferromagnetic steel sheet (101) having a first free face and with another double-sided aluminium-coated low-carbon ferromagnetic steel sheet (103) having a second free face, - stamping the multilayer formed part to form a metal body (110) comprising a heating surface (120) corresponding to a first free surface and a cooking surface (130) corresponding to a second free surface, The double-sided aluminum-plated low-carbon ferromagnetic steel plate (101) comprises a low-carbon steel magnetic substrate (111), wherein the low-carbon steel magnetic substrate has an outer layer (112) containing an aluminum-based matrix on each of its two surfaces, and an intermediate layer (113) containing an iron / aluminum intermetallic compound is arranged between the low-carbon steel magnetic substrate (111) and the outer layer (112), wherein the intermediate layer (113) is formed of an iron / aluminum intermetallic compound that does not have interference characteristics with respect to a magnetic field, and the metal body (110) is subjected to a heat treatment exceeding 500° C., so that the thickness of the intermediate layer (113) is greater than 5 μm and at least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 27 μm, - implementing a protective coating (121) on the heating surface (120), - A non-stick coating (131) is implemented on the cooking surface (130) to form a cooking surface (132).

24. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 23, characterized in that After stamping of the multilayer formed part and before applying the protective coating (121) and the non-stick coating (131), the method comprises a step of treating the peripheral portion of the multilayer formed part to obtain a flange (125) or a curled edge (126) or an open curled edge (127).

25. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 23 or 24, characterized in that The protective coating (121) is a PTFE type coating, or an enamel type coating, or a lacquer type coating, or a ceramic type coating, or a sol-gel type coating.

26. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 23 or 24, characterized in that The non-stick coating (131) is a PTFE type coating, or a ceramic type coating, or a sol-gel type coating.

27. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 23 or 24, characterized in that The multi-layered formed part is a disc.

28. The method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 23, characterized in that At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 20 μm.

29. The method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 23, characterized in that At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 18 μm.

30. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 1 to 13, comprising the following steps: - cutting or providing a multilayer formed part from an aluminium sheet (102) metallurgically assembled with a double-sided aluminium-coated low-carbon ferromagnetic steel sheet (101) having a first free face and with another double-sided aluminium-coated low-carbon ferromagnetic steel sheet (103) having a second free face, - implementing a protective coating (121) on a first free face and a non-stick coating (131) on a second free face, in order to obtain a coated multilayer shaped part, - stamping the coated multilayer formed part to form a coated metal body (110) comprising a heating surface (120) with a protective coating (121) and a cooking surface (130) with a non-stick coating (131) to form a cooking surface (132), The double-sided aluminum-plated low-carbon ferromagnetic steel plate (101) comprises a low-carbon steel magnetic substrate (111), wherein the low-carbon steel magnetic substrate has an outer layer (112) containing an aluminum-based matrix on each of its two surfaces, and an intermediate layer (113) containing an iron / aluminum intermetallic compound is arranged between the low-carbon steel magnetic substrate (111) and the outer layer (112), wherein the intermediate layer (113) is formed of an iron / aluminum intermetallic compound that does not have interference characteristics with respect to a magnetic field, and the metal body (110) is subjected to a heat treatment exceeding 500° C., so that the thickness of the intermediate layer (113) is greater than 5 μm and at least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 27 μm.

31. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 30, characterized in that After achieving the protective coating (121) and the non-stick coating (131) and after stamping the coated multilayer formed part, the method includes a step of treating the peripheral portion of the coated multilayer formed part to obtain a flange (125) or a curled edge (126) or an open curled edge (127).

32. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 30 or 31, characterized in that The protective coating (121) is a PTFE type coating or a lacquer type coating.

33. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 30 or 31, characterized in that The non-stick coating (131) is a PTFE type coating.

34. Method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to any one of claims 30 or 31, characterized in that The multi-layered formed part is a disc.

35. The method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 30, characterized in that At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 20 μm.

36. The method for obtaining a coated multilayer metal cooking support (100) compatible with induction heating according to claim 30, characterized in that At least on the bottom (122) of the heating surface (120), the outer layer (112) has a thickness of less than 18 μm.

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