Sheet metal molding for motor vehicles and process for producing a sheet metal molding for motor vehicles

Abstract

A motor vehicle sheet metal molding of the invention is produced by hot forming from a metal sheet composed of an aluminum alloy which cannot be precipitation hardened, which contains at least magnesium and optionally manganese in addition to aluminum as alloy component. The motor vehicle sheet metal molding after forming has, at least locally, degrees of deformation which are above the forming limit curve of the aluminum alloy at room temperature. To produce the motor vehicle sheet metal molding, the metal sheet is heated at least locally to a temperature in the range from 200° C. to 400° C. over a period of from 1 to 60 seconds. The heated metal sheet is subsequently placed in a forming tool of a forming press and formed to produce the motor vehicle sheet metal molding.

What is claimed is: 
     
         1 . A motor vehicle sheet metal molding made by a process comprising the steps of:
 heating at least portions of a sheet metal made of a non precipitation-hardenable aluminum alloy comprising aluminum and magnesium, said sheet metal being of a material state defined by a temper designation according to European norm EN515:1993 selected from the group consisting of H12, H14, H16, H18, H19, H22, H24, H26, H28, H32, H34, H36 and H38; and   forming the sheet metal into the motor vehicle sheet metal molding in a cold forming tool such that at least one region of the motor vehicle sheet metal molding has a degree of deformation above a forming limit curve of the aluminum alloy at room temperature.   
     
     
         2 . The motor vehicle sheet metal molding of  claim 1 , wherein the aluminum alloy comprises manganese. 
     
     
         3 . The motor vehicle sheet metal molding of  claim 1 , wherein a yield strength R p0.2  of the motor vehicle sheet metal molding is reduced by maximally 30% relative to the sheet metal. 
     
     
         4 . The motor vehicle sheet metal molding of  claim 1 , wherein the motor vehicle sheet metal molding has a yield strength R p0.2  which is at least 20% higher than a yield strength of a comparable motor vehicle sheet metal molding made from another sheet metal, said another sheet metal being made of the aluminum alloy and being of a material state defined by a temper designation O/H111 according to the European standard EN515:1993.