Patent ID: 9085328
Filing Date: 2015-07-21
Classification: B62D,C22C,C22F,Y10T

Abstract:
1. 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, 0.05 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 at least more than 40% of the elements Mg and Si in a form of Si and Mg wherein no homogenization step of a casting bar is performed before the hot rolling step and wherein said heat treatment comprises performing a partial heterogenization anneal of the aluminum alloy sheet rolled to final thickness wherein coils are annealed in a chamber oven at a temperature of from 330° C. to 400° C. and for a retention time of between 1 and 4 hours.