Automobile Body Part

Abstract

In a car body or component of a car body with at least one first component of sheet metal of a first aluminium alloy (A) and at least one second component of sheet metal of a second aluminium alloy (B), the first and second aluminium alloy are of type AlMgSi and in the sheet metal of the second aluminium alloy (B) a substantial part of the elements Mg and Si, which are required to achieve artificial ageing in solid solution, is present in the form of separate Mg 2 Si and/or Si particles in order to avoid artificial ageing. As well as common recycling of process scrap in the production of the various components and simple scrap recycling of the body parts from the end of life car, by reduction of the hardening capacity of the second component during artificial ageing of the body as part of the paint baking cycle, the car body has an improved impact protection for pedestrians in comparison with solutions according to the prior art.

1 - 22 . (canceled) 
     
     
         23 . A method for the production of car body sheet, the method comprising:
 (a) casting an ingot of aluminum alloy consisting essentially of the following alloy elements:   0.30 to 0.50 weight percent silicon;   0.30 to 0.50 weight percent magnesium;   max. 0.20 weight percent copper;   0.50 to 0.20 weight percent iron;   max. 0.10 weight percent manganese;   max. 0.15 weight percent vanadium; and   aluminum as the remainder with production-related contaminants;   (b) hot rolling, cold rolling, solution annealing, and coiling a final sheet product, wherein heat treatment conditions during such processing steps precipitate Mg and Si in a form wherein Mg and Si are no longer substantially available for subsequent artificial aging.   
     
     
         24 . A method according to  claim 23 , wherein the heat treatment conditions are such that more than 60% of the elements Mg and Si are precipitated in a form where they are no longer available for subsequent artificial aging. 
     
     
         25 . A method according to  claim 23 , wherein the heat treatment comprises performing a partial solution annealing step on the aluminum alloy sheet at a temperature range of 450° C. to 520° C. for a maximum of about 30 seconds. 
     
     
         26 . A method according to  claim 24 , wherein the heat treatment comprises performing a partial solution annealing step on the aluminum alloy sheet at a temperature range of 450° C. to 520° C. for a maximum of about 30 seconds. 
     
     
         27 . A method according to  claim 23 , wherein the heat treatment comprises performing a partial heterogenization anneal wherein coils are annealed at a temperature of from 330° C. to 400° C. and for a retention time of between 1 and 4 hours. 
     
     
         28 . A method according to  claim 24 , wherein the heat treatment comprises performing a partial heterogenization anneal wherein coils are annealed at a temperature of from 330° C. to 400° C. and for a retention time of between 1 and 4 hours. 
     
     
         29 . An aluminum sheet made according to  claim 23 . 
     
     
         30 . An aluminum sheet made according to  claim 24 . 
     
     
         31 . An aluminum sheet made according to  claim 25 . 
     
     
         32 . An aluminum sheet made according to  claim 26 . 
     
     
         33 . An aluminum sheet made according to  claim 27 . 
     
     
         34 . An aluminum sheet made according to  claim 28 . 
     
     
         35 . An automobile body or component thereof comprising first and second AlMgSi type aluminum alloy sheet metal components, wherein the second aluminum alloy component consists essentially of:
 0.30 to 0.50 weight percent silicon;   0.30 to 0.50 weight percent magnesium;   max. 0.20 weight percent copper;   0.50 to 0.20 weight percent iron;   max. 0.10 weight percent manganese;   max. 0.15 weight percent vanadium; and   aluminum as the remainder with production-related contaminants;   
       and wherein during production the second aluminum alloy component is subjected to a partial solution annealing step at a temperature range of 450° C. to 520° C. for a maximum of about 30 seconds. 
     
     
         36 . An automobile body or component thereof in accordance with  claim 35 , wherein the first AlMgSi type aluminum alloy sheet metal component consists essentially of:
 0.6 to 1.2 weight percent silicon;   0.3 to 0.8 weight percent magnesium;   max. 0.8 weight percent copper;   max 0.4 weight percent iron;   max. 0.3 weight percent manganese;   max. 02 weight percent vanadium; and   aluminum as the remainder with production-related contaminants.