US Patent 7763130 Thermal process to improve metallurgical characteristics

A thermal process for treating a metal to improve at least one structural characteristic of the metal comprising: placing a metal with a metal temperature within a thermal control apparatus, introducing a cryogenic material to decrease the metal temperature, while preventing over-stressing of the metal, to a first target temperature ranging from −120 degrees Fahrenheit to −380 degrees Fahrenheit at a first temperature rate, ranging from degrees Fahrenheit per minute to 20 degrees Fahrenheit per minute, stopping the introduction of cryogenic material once the first target temperature is reached, and increasing the chamber temperature to a second target temperature ranging from 0 degrees Fahrenheit to 1400, and increasing the metal temperature to the second target temperature at a second temperature rate ranging from 0.25 degrees Fahrenheit per minute to 20 degrees Fahrenheit per minute, resulting in a treated metal without fractures.