Method for producing a pressure vessel

Abstract

The present invention relates to a method of manufacturing a pressure vessel.

1 . A method of manufacturing a pressure vessel having a base at one end of the pressure vessel, a wall section, and a neck section which is at the opposite end of the pressure vessel from the base and has an opening, wherein the method comprises the following steps:
 providing at least a first blank, where the first blank consists of a carbon steel;   creating the wall section from the at least first blank by flow forming to give a pressure vessel preform;   creating the neck section from the pressure vessel preform by swivel forming to give a pressure vessel;   
       wherein the pressure vessel, after the swivel forming, is heated at least partly to a temperature Ac1 at which the microstructure of the carbon steel is transformed at least partly to austenite and then cooled down at least in sections by active cooling such that the microstructure is at least partly transformed to martensite and/or bainite, and hence a tensile strength R m of at least 1000 MPa is established at least in sections of the carbon steel of the pressure vessel. 
     
     
         2 . The method as claimed in  claim 1 , wherein the creation of the pressure vessel preform is preceded by forming of a base in the at least first blank in a deep drawing step. 
     
     
         3 . The method as claimed in  claim 2 , wherein active heating is conducted at least in some regions at least one of before and during the creation of the pressure vessel preform and/or of the neck section. 
     
     
         4 . The method as claimed in  claim 3 , wherein the active heating is conducted at a temperature of at least 300° C. 
     
     
         5 . The method as claimed in  claim 3 , wherein the carbon steel, as well as Fe and unavoidable impurities from the production, contains the following chemical elements in % by weight: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   C: 
                   0.01 to 0.7%, 
                 
                     
                   Si: 
                   0.01 to 3.0%, 
                 
                     
                   Mn: 
                   0.01 to 3.0%, 
                 
                     
                   N: 
                   up to 0.1%, 
                 
                     
                   P: 
                   up to 0.1%, 
                 
                     
                   S: 
                   up to 0.1%; 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         6 . The method as claimed in  claim 5 , wherein a second blank consisting of an austenitic steel is provided. 
     
     
         7 . The method as claimed in  claim 6 , wherein the austenitic steel, as well as Fe and unavoidable impurities from the production, contains the following chemical elements in % by weight: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Cr: 
                   11.0 to 22.0%, 
                 
                     
                   Ni: 
                   5.0 to 15.0%, 
                 
                     
                   C: 
                   up to 0.2%, 
                 
                     
                   Si: 
                   up to 1.5%, 
                 
                     
                   Mn: 
                   up to 3.0%, 
                 
                     
                   N: 
                   up to 0.2%, 
                 
                     
                   P: 
                   up to 0.1%, 
                 
                     
                   S: 
                   up to 0.1%. 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         8 . The method as claimed in  claim 6 , wherein the austenitic steel, as well as Fe and unavoidable impurities from the production, contains the following chemical elements in % by weight: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   C: 
                   up to 0.6%, 
                 
                     
                   Si: 
                   up to 1.5%, 
                 
                     
                   Mn: 
                   4.0 to 25.0%, 
                 
                     
                   N: 
                   up to 0.2%, 
                 
                     
                   P: 
                   up to 0.1%, 
                 
                     
                   S: 
                   up to 0.1% 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         9 . The method as claimed in  claim 8 , wherein the second blank is provided simultaneously with the first blank and the creating of the wall section from the two blanks is performed by flow forming to give a pressure vessel preform, and then the neck section is created from the pressure vessel preform by swivel forming to give a pressure vessel. 
     
     
         10 . The method as claimed in  claim 8 , wherein the second blank is provided separately, wherein the second blank is used to create a wall section by flow forming to give a pressure vessel preform, wherein the external diameter (Da) of the pressure vessel preform made from the second blank is equal to or less than the internal diameter (di) of the pressure vessel preform produced by flow forming from the first blank, wherein the pressure vessel preform made from the second blank is then introduced into the pressure vessel preform made from the first blank before the neck section is created from the pressure vessel preforms by swivel forming to give a pressure vessel. 
     
     
         11 . The use of a pressure vessel produced as claimed in  claim 10  for storage of pressurized fluids in mobile applications. 
     
     
         12 . The method of  claim 5  wherein the carbon steel, as well as Fe and unavoidable impurities from the production, contains the following chemical elements in % by weight:
 at least one or more than one element from the group of (Al, Cr, Cu, Mo, Ni, Nb, Ti, V, B, Sn, Ca, REM): 
 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Al: 
                   up to 1.0%, 
                 
                     
                   Cr: 
                   up to 1.0%, 
                 
                     
                   Cu: 
                   up to 1.0%, 
                 
                     
                   Mo: 
                   up to 1.0%, 
                 
                     
                   Ni: 
                   up to 1.0%, 
                 
                     
                   Nb: 
                   up to 0.2%, 
                 
                     
                   Ti: 
                   up to 0.2%, 
                 
                     
                   V: 
                   up to 0.2%, 
                 
                     
                   B: 
                   up to 0.01%, 
                 
                     
                   Sn: 
                   up to 0.1%, 
                 
                     
                   Ca: 
                   up to 0.1%, 
                 
                     
                   REM: 
                   up to 0.2%. 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         13 . The method as claimed in  claim 8 , wherein the austenitic steel, as well as Fe and unavoidable impurities from the production, contains the following chemical elements in % by weight:
 at least one or more than one element from the group of (Al, Cr, Cu, Mo, Ni, Nb, Ti, V, B, Sn, Ca):   
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Al: 
                   up to 3.0%, 
                 
                     
                   Cr: 
                   up to 4.0%, 
                 
                     
                   Cu: 
                   up to 1.0%, 
                 
                     
                   Mo: 
                   up to 1.0%, 
                 
                     
                   Ni: 
                   up to 2.0%, 
                 
                     
                   Nb: 
                   up to 0.5%, 
                 
                     
                   Ti: 
                   up to 0.5%, 
                 
                     
                   V: 
                   up to 0.5%, 
                 
                     
                   B: 
                   up to 0.01%, 
                 
                     
                   Sn: 
                   up to 0.1%, 
                 
                     
                   Ca: 
                   up to 0.1%.