Method for the Manufacture of an Austenitic Product as Well as the Use Thereof

Abstract

The present invention relates to a method to produce an austenitic alloy by an austenitic stainless substrate alloy of low Al content being coated with an alloy of higher Al content at a temperature between 100° C. and 600° C., so that the resulting product has an Al content of 4.5-12% by weight.

1 . Method to produce an austenitic alloy, wherein an austenitic substrate alloy of low Al content is coated with at least one layer of an alloy of higher Al content at a temperature between 100° C. and 600° C., so that the resulting product has an Al content of 4.5-12% by weight. 
   
   
       2 . Method to produce an austenitic alloy according to  claim 1 , wherein a substrate alloy having the following composition (in % by weight):
 20-70% of Ni,   15-27% of Cr,   0-5% of Al,   0-4% of Mo and/or W,   0-2% of Si,   0-3% of Mn,   0-2% of Nb,   0-0.5% of Ti,   0-0.1% of one or more rare earth metals (REM)   balance Fe and normally occurring impurities is coated with at least one layer of a composition of higher Al content.   
   
   
       3 . Method for the manufacture of an austenitic alloy according to  claim 1 , wherein at least one layer is aluminium. 
   
   
       4 . Method for the manufacture of an austenitic alloy according to  claim 1 , wherein at least one layer is an aluminium-based alloy. 
   
   
       5 . Method for the manufacture of an austenitic alloy according to  claim 1 , in which the aluminium-based alloy is Al having 0.5 to 25% by weight of Si. 
   
   
       6 . Method for the manufacture of an austenitic alloy according to  claim 1 , wherein the austenitic final product has the following composition (in % by weight):
 0-0.2% of C,   0-0.1% of N,   25-70% of Ni,   15-25% of Cr,   4.5-12% of Al,   0-4% of Mo and/or W,   0-4% of Si,   0-3% of Mn,   0-2% of Nb,   0-0.5% of Ti,   0-0.5% of Y, Sc, Zr and/or Hf,   0-0.2% of one or more rare earth metals (REM) such as, e.g., Ce, La, Sm, balance Fe and normally occurring impurities.   
   
   
       7 . Austenitic alloy with an Al content of 4.5-12% by weight, wherein it is manufacturable by the method according to  claim 1 . 
   
   
       8 . Use of the method according to  claim 1  for producing material to be used in high temperature applications such as supporting material in catalytic converters and resistive heating.