Method for producing a three-dimensionally formed armoring component for motor vehicle bodies

Abstract

A method produces three-dimensionally formed armoring components for vehicle bodies. The armoring components are produced in a repeatedly accurate manner with minimal post-machining requirements and with lower dimensional tolerances than comparable weldments. Sheet metal molded parts are produced from hardenable steel by a thermal pre-treatment, the heating speed and temperature being selected at least until the austenitic or partially austenitic state is achieved depending on the alloy content, and formed armoring components are produced from press-forming and optionally subsequently subjected to quench or thermal treatment. The hot-forming and quench-hardening of the steel is performed in one working cycle, the austenitic steel plates are formed within a maximum period of 90 seconds by a compression mold, the entire formed component is held in contact with the compression mold, and the formed component is cooled in the closed mold, with a cooling speed corresponding to a material-specific critical cooling speed.

1 - 11 . (canceled)  
   
   
       12 . A method for producing a three-dimensionally formed armoring component for vehicle bodies, which comprises the steps of: 
 producing sheet metal preforms from hardenable steel by the steps of: 
 thermally pre-treating a steel sheet blank by selecting a heating speed and a heating temperature until an austenitic state or partly austenitic state, dependent on alloy content, is reached resulting in an austenitized steel sheet blank;  
 carrying out hot forming and quench hardening of the austenitized steel sheet blank in one operation, by the steps of: 
 forming the austenitized steel sheet blank in a press die within a time of at most 90 seconds resulting in a formed component;  
 holding the formed component in full-area contact with the press die resulting in cooling of the formed component in the press die being in a closed state; and  
 performing the cooling of the formed component in the closed press die at a cooling rate corresponding at least to a material-specific critical cooling rate.  
 
   
   
   
       13 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises forming the steel sheet blank from a sheet of hardenable and maraging steel.  
   
   
       14 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises forming the steel sheet blank with an initial hardness, during hardening in hardening oil, to be higher than 45 HRC or with a hardness after artificial ageing to be higher than 45 HRC.  
   
   
       15 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , wherein during heating to the heating temperature being an austenitizing temperature, the alloy content being alloying elements are dissolved predominantly in austenite.  
   
   
       16 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises selecting a heat treatment time and the heating temperature for austenitization in dependence on a component material and material thickness to minimize scaling, skin decarburization and grain growth.  
   
   
       17 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises forming the austenitized steel sheet blank at an austenitizing temperature dependent on the alloy content or at temperatures at which the steel sheet blank is in the partly austenitized state.  
   
   
       18 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises, after the forming step, holding the press die closed for a period of time of at least 50 to 500 seconds to achieve a desired cooling temperature.  
   
   
       19 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises cooling the press die with a coolant.  
   
   
       20 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 19 , which further comprises selecting the coolant from the group consisting of water, ammonia, compressed air, and a combination of at least one of water, ammonia and compressed air.  
   
   
       21 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises subjecting the formed component after the cooling step, to a final heat treatment in a form of expansion and/or tempering.  
   
   
       22 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 12 , which further comprises subjecting the formed component after the cooling step to a further step of retreating by tempering, hardening and tempering, age hardening or artificial ageing.  
   
   
       23 . A method for producing a three-dimensionally formed armoring component for vehicle bodies, which comprises the steps of: 
 producing sheet metal preforms from hardenable steel by the steps of: 
 thermally pre-treating a steel sheet blank by selecting a heating speed and a heating temperature at least until an austenitic state or partly austenitic state, dependent on an alloy content, is reached resulting in an austenitized steel sheet blank;  
 carrying out hot forming and quench hardening of the austenitic steel sheet blank in one operation, by the steps of: 
 cooling a press die to at least approximately 70° C.; forming the austenitized steel sheet blank still in the austenitic state or the partly austenitic state in the press die resulting in a formed component;  
 holding the formed component in full-area contact with the press die being a closed press die; and  
 performing further cooling of the formed component without calibration, but with a pressing force being maintained, for dissipating heat from the formed component in the press die.  
 
   
   
   
       24 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises forming the steel sheet blank from a sheet of hardenable and maraging steel.  
   
   
       25 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises forming the steel sheet blank with an initial hardness, during hardening in hardening oil, to be higher than 45 HRC or with a hardness after artificial ageing to be higher than 45 HRC.  
   
   
       26 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , wherein during heating to the heating temperature being an austenitizing temperature, the alloy content being alloying elements are dissolved predominantly in austenite.  
   
   
       27 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises selecting a heat treatment time and the heating temperature for austenitization in dependence on a component material and material thickness to minimize scaling, skin decarburization and grain growth.  
   
   
       28 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises forming the austenitized steel sheet blank at an austenitizing temperature dependent on the alloy content or at temperatures at which the steel sheet blank is in the partly austenitized state.  
   
   
       29 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises, after the forming step, holding the press die closed for a period of time of at least 50 to 500 seconds to achieve a desired cooling temperature.  
   
   
       30 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises cooling the press die with a coolant.  
   
   
       31 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 30 , which further comprises selecting the coolant from the group consisting of water, ammonia, compressed air, and a combination of at least one of water, ammonia and compressed air.  
   
   
       32 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises subjecting the formed component after the cooling step, to a final heat treatment in a form of expansion and/or tempering.  
   
   
       33 . The method for producing the three-dimensionally formed armoring component for vehicle bodies according to  claim 23 , which further comprises subjecting the formed component after the cooling step to a further step of retreating by tempering, hardening and tempering, age hardening or artificial ageing.