Method for producing a support film for catalytic converters

Abstract

A method produces a support film for catalytic converters with application temperatures <900° C., including an iron-chromium-aluminum alloy containing 8-14% by weight Cr, 1-4% by weight Al and iron as the remainder, along with melting impurities, by the alloy being cast in the form of ingots, the ingots being hot-rolled or forged into slabs of thicknesses between 150 and 400 mm, the slabs in the hot state either being cooled down to room temperature in air/oil/water or first placed with an insert into an oven installation in the temperature range of 475° C. to 700° C. and, following a heat-retention phase for a holding period of between 0.5 and 100 hours at a defined holding temperature of between 475° C. and 700° C., cooled down to room temperature outside the furnace installation.

1 : A method for the manufacture of a support foil for catalytic converters with application temperatures of ≤900° C., comprising an iron-chromium-aluminum alloy with contents (in wt %) of
 Cr 8-14% 
 Al 1-4% 
 Fe the rest as well as melting-related impurities 
 in which the alloy is cast in the form of ingots, 
 the ingots are hot-rolled or forged to thicknesses between 150 and 400 mm to obtain slabs, 
 the slabs in the hot condition are either 
 cooled to room temperature in air/oil/water 
 or 
 first introduced with an insert into a furnace system in the temperature range from 475° C. to 700° C. and, after a hot-holding phase with a holding duration between 0.5 and 100 hours at a defined holding temperature between 475° C. and 700° C., cooled to room temperature outside the furnace system. 
 
     
     
         2 : The method according to  claim 1 , wherein the contents of the elements are adjusted to
 Cr 9-13%   Al 1.0-3.5%   Fe the rest as well as melting-related impurities   in the alloy.   
     
     
         3 : The method according to  claim 1 , wherein the contents of the elements are adjusted to
 Cr 10-13%   Al 2-3.5%   Fe the rest as well as melting-related impurities   in the alloy.   
     
     
         4 : The method according to  claim 1 , wherein the contents of the elements are adjusted to
 Cr 9-12%   Al 1.5-3%   Fe the rest as well as melting-related impurities   in the alloy.   
     
     
         5 : The method according to  claim 1 , wherein the following elements may also be optionally added to the alloy:
 Y up to 0.3% and/or   Hf up to 0.3% and/or   La up to 0.3% and/or   cerium up to 0.3%.   
     
     
         6 : The method according to  claim 1 , wherein the element Zr may be optionally added in contents of >0.0 up to 0.5% to the alloy. 
     
     
         7 : The method according to  claim 1 , wherein the slab, after its cooling to room temperature, is rolled by processes of hot/cold-rolling processes to strip as well as foil, wherein, if necessary, at least one process of heat treatment of the strip or respectively foil is carried out. 
     
     
         8 . (canceled)