Cooking vessel for induction heating and alloy and method for producing such a vessel

Abstract

Cooking vessel intended to be induction heated, comprising a heating part made of a ferromagnetic alloy having a Curie temperature of between 150° C. and 370° C. and a magnetostriction coefficient λ s ≦5×10 −6 in absolute value. FeNiCuX ferromagnetic alloy for the manufacture of the cooking vessel, the chemical composition of which comprises from 50% to 85% of Ni, less than 50% of Cu, less than 12% of X=Cr+Mo+Mn+Si+Al+W+Nb+V+Ti, the balance being iron and impurities; the composition satisfies the relationships (35/25)×(75-Ni)≦Cu≦(50/35)×(85-Ni) and (7/20)×(Ni-65)≦X≦(12/35)×(Ni-50). Production method and method of use.

1 . A cooking vessel comprising a heating part, said heating part comprising a ferromagnetic alloy, wherein said ferromagnetic alloy has a Curie temperature of between 150° C. and 370° C. and a magnetostriction coefficient λ s ≦5×10 −6  in absolute value.  
     
     
         2 . The cooking vessel as claimed in    claim 1   , wherein the Curie temperature is less than 350° C.  
     
     
         3 . The cooking vessel as claimed in    claim 1   , wherein the ferromagnetic alloy has a Curie temperature of between 275° C. and 340° C. and a magnetostriction coefficient λ s ≦3× 10 −6  in absolute value.  
     
     
         4 . The cooking vessel as claimed in    claim 3   , wherein the Curie temperature is less than 325° C.  
     
     
         5 . The cooking vessel as claimed in    claim 1   , wherein the ferromagnetic alloy is an FeNiCuX alloy, X being one or more elements taken from Cr, Mo, Mn, Si, Al, W, Nb, V and Ti, the chemical composition of the alloy (in % by weight) comprising: 
 50%≦Ni≦85%    0%≦Cu≦50%    0%≦X≦12%    (35/25)×(75-Ni)≦Cu≦(50/35)×(85-Ni)    (7/20)×(Ni-65)≦X≦(12/35)×(Ni-50)    with: X=Cr+Mo+Mn+Si+Al+W+Nb+V+Ti, iron and impurities resulting from smelting.    
     
     
         6 . The cooking vessel as claimed in    claim 5   , wherein the chemical composition of the alloy is such that: 
 55%≦Ni≦65%    22%≦Cu≦36%    0%≦X≦3%.    
     
     
         7 . The cooking vessel as claimed in    claim 6   , wherein the copper content is between 25% and 35%.  
     
     
         8 . The cooking vessel as claimed in    claim 1   , wherein the heating part is an insert incorporated into the bottom of the vessel.  
     
     
         9 . The cooking vessel as claimed in    claim 8   , wherein the insert is a plate.  
     
     
         10 . The cooking vessel as claimed in    claim 1   , wherein the heating part constitutes the wall of a vessel.  
     
     
         11 . A FeNiCuX ferromagnetic alloy, X being one or more elements taken from Cr, Mo, Mn, Si, Al, W, Nb, V and Ti, the chemical composition of the alloy (in % by weight) comprising: 
 50%≦Ni≦85%    0%≦Cu≦50%    0%≦X≦12%    (35/25)×(75-Ni)≦Cu≦(50/35)×(85-Ni)    (7/20)×(Ni-65)≦X≦(12/35)×(Ni,-50)    with: X=Cr+Mo+Mn+Si+Al+W+Nb+V+Ti, iron and impurities resulting from smelting, the alloy having a Curie temperature of between 150° C. and 370° C. and a magnetostriction coefficient λ s ≦5×10 −6  in absolute value.    
     
     
         12 . The ferromagnetic alloy as claimed in    claim 11   , wherein the Curie temperature is less than 350° C.  
     
     
         13 . The ferromagnetic alloy as claimed in    claim 11   , wherein the chemical composition comprises: 
 55%≦Ni≦65%    22%≦Cu≦36%    0%≦X≦3%.    
     
     
         14 . The ferromagnetic alloy as claimed in    claim 13   , wherein the copper content is between 25% and 35%.  
     
     
         15 . The ferromagnetic alloy as claimed in    claim 11   , which has a Curie temperature of between 275° C. and 340° C. and a magnetostriction coefficient λ s ≦3×10 −6  in absolute value.  
     
     
         16 . The ferromagnetic alloy as claimed in    claim 15   , wherein its Curie temperature is less than 325° C.  
     
     
         17 . A method of cooking, comprising heating food or a food ingredient in the cooking vessel of    claim 1   .  
     
     
         18 . A method of cooking, comprising heating food or a food ingredient in the cooking vessel of    claim 5   .  
     
     
         19 . A method of cooking, comprising heating food or a food ingredient in the cooking vessel of    claim 6   .  
     
     
         20 . A method of cooking, comprising heating food or a food ingredient in the cooking vessel of    claim 9   .