Exhaust-gas heat exchanger made of duplex steel

Abstract

The present invention relates to an exhaust-gas heat exchanger for a motor vehicle, having an outer casing and plates arranged therein lying one above another in layers, wherein a fin plate made of austenitic steel material is arranged in an inner cassette made of ferritic steel material or made of duplex steel and at least two inner cassettes are arranged one above another like plates and the outer casing is formed from duplex steel and engages around the inner cassettes.

1 . An exhaust-gas heat exchanger for a motor vehicle, having an outer casing and plates arranged therein lying one above another in layers, wherein a fin plate made of austenitic steel material is arranged in an inner cassette made of ferritic steel material or made of duplex steel and at least two inner cassettes (are arranged one above another plate-like and the outer casing is formed from duplex steel and engages around the inner cassettes. 
     
     
         2 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein a first flow duct is formed between an inner lateral surface of the casing and an outer lateral surface of the inner cassettes. 
     
     
         3 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein a second flow duct is formed in the inner cassettes. 
     
     
         4 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein the inner cassettes are embodied in a two-shell form by two shells, the two shells being soldered to one another. 
     
     
         5 . The exhaust-gas heat exchanger as claimed in  claim 4 , wherein the shells of the inner cassettes have outwardly directed spacing bosses. 
     
     
         6 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein the casing has inwardly directed spacing bosses. 
     
     
         7 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein the casing is embodied as an outer shell in a two-shell form by two shells, the two shells being soldered to one another. 
     
     
         8 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein the duplex steel used is an alloy of the number 1.4462 or 1.4362 or 1.4162. 
     
     
         9 . The exhaust-gas heat exchanger as claimed in  claim 1 , wherein brackets made of duplex steel are arranged on the casing. 
     
     
         10 . The exhaust-gas heat exchanger as claimed in  claim 9 , wherein the brackets are formed in a one piece and materially integral form on the casing.