Patent attributes
In a method for increasing steel impact toughness, the steel composition contains from about 5 wt % to about 10 wt % manganese and has a martensite finish temperature (Mf) below room temperature. The steel composition is exposed to hot forming to form a steel part. During hot forming, the steel composition is subjected to a heat treatment temperature above its fully austenite formed temperature, is transferred to a die, and while in the die, is simultaneously formed and quenched. In one example, quenching cools the steel composition to room temperature, and the steel part is removed from the die and reheated to a baking temperature ranging from about 120° C. to about 400° C. In another example, quenching is interrupted at an interruption temperature ranging from about 120° C. to about 400° C., and the steel composition is maintained at the interruption temperature for a predetermined time and then is cooled to room temperature.
