Laboratory tests were conducted in flowing air at 1800 to 2200°F (982 to 1204°C) for 1008 hours, with specimens cycled to room temperature once every 168 hours.
Laboratory tests were conducted at 2000°F (1093°C) in still air (box furnace), with specimens being cycled to room temperature once every 30 days.
Plate exposed for 360 days ( 8,640 hours) in still air, except for 1800°F test, which was exposed for 720 days (17,280 hours). Cycled once per month.
Plate exposed for 360 days ( 8,640 hours) in still air. Cycled once every two months.