Patent ID: 8307680

Claim:
A process for making a hot stamped coated steel sheet product, comprising: (A) heating an aluminum- or aluminum alloy pre-coated steel sheet in a furnace preheated to a temperature and during a time defined by trapezoid ABCD having heating time, temperature coordinates of about A (3 minutes, 930° C.), B (6 minutes, 930° C.), C (13 minutes, 880° C.), and D (4.5 minutes, 880° C.) if the thickness of said sheet is greater than or equal to 0.7 mm and less than or equal to 1.5 mm, and by trapezoid EFGH having heating time, temperature coordinates of about E (4 minutes, 940° C.), F (8 minutes, 940° C.), G (13 minutes, 900° C.), and H (6.5 minutes, 900° C.) if the thickness of said sheet is greater than 1.5 mm and less than or equal to 3 mm, at a heating rate V c between 20 and 700° C. comprised between 4 and 12° C./s, to obtain a heated blank; (B) transferring said heated blank to a die; and (C) stamping said heated blank in said die, to thereby obtain a hot stamped steel sheet product, and wherein the said heated product is cooled at a mean rate of at least 50° C./s during an interval between when said product exits said furnace and when said product reaches 400° C., wherein an elapsed time between when said heated blank exits said furnace and said stamping commences is not more than 10 seconds.