TASK 70-44-00-800-010
1 . General.
A.Heat treating is a general term which refers to a wide variety of processes (annealing, hardening, stress-relieving, normalizing, nitriding, etc.) which change some of the physical, mechanical, and chemical properties of metal. These changes are caused by modification of either the crystalline structure or the chemical composition of the metal, or by a combination of the two. Precise control of maximum temperature, rate of temperature rise, cooling rate, type of chemical atmosphere, and other factors are essential to the attainment of desired results. The specific processes described here are those necessary for restoring the original physical, mechanical, and chemical characteristics to metal parts following repair operations such as welding or brazing.
NOTE:
Use actual part temperature as established by a separate thermocouple attached to the part to determine time-at-temperature, not the furnace thermocouple.
NOTE:
For all heat treatment cycles in this 70-44-xx section, the specified time is the time that the entire part is at temperature. The permitted time tolerance is plus or minus 10 percent unless the cycle specifies differently.