Patent ID: 11951522
Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  C | IPC B  C

Claim 15:
16. A method of forming a shaped steel object, the method comprising:
heating a blank to a temperature of greater than or equal to about 900° C. to less than or equal to about 950° C. for a time period of greater than or equal to about 1 minute to less than or equal to about 60 minutes to generate a heated blank, the blank being composed of an alloy composition comprising:
carbon (C) at a concentration of greater than or equal to about 0.05 wt. % to less than or equal to about 0.5 wt. % of the alloy composition,
manganese (Mn) at a concentration of greater than or equal to about 4 wt. % to less than or equal to 5.4 wt. % of the alloy composition,
aluminum (Al) at a concentration of greater than or equal to 2 wt. % to less than or equal to about 8 wt. % of the alloy composition,
vanadium (V) at a concentration of greater than 0 wt. % to less than or equal to about 0.4 wt. % of the alloy composition,
zirconium (Zr) at a concentration of greater than 0 wt. % to less than or equal to about 0.5 wt. % of the alloy composition,
nitrogen (N) at a concentration of greater than 0 wt. % to less than 0.001 wt. % of the alloy composition, and
a balance of the alloy composition being iron (Fe);
forming the heated blank into a predetermined shape to generate a stamped object;
quenching the stamped object by decreasing the temperature of the stamped object to about ambient temperature to form a shaped steel object comprising martensite and retained austenite; and
tempering the shaped steel object by heating the shaped steel object to greater than or equal to about 150° C. to less than or equal to about 300° C. for a time period of greater than or equal to about 1 minute to less than or equal to about 120 minutes and then decreasing the temperature of the shaped steel object to ambient temperature.