For a metal alloy, which one of the following descriptions relates to the stress relief annealing process
1
Heating the work piece material above its recrystallization temperature, soaking and then cooling in still air.
2
Heating the work piece material below its recrystallization temperature, holding for some time and then furnace cooling.
3
Heating the work piece material up to its recrystallization temperature and then rapid cooling.
4
Heating the work piece up to its recrystallization temperature and cooling to room temperature alternately for a few cycles.