Usually conducted several hundred degrees above AC 3 . Typically in the range of 1800F to 2000F. 7. Burning Range - Results in steels that have to be remelted due to liquation and other problems. Stress Relieving - Heating to below AC 1 and holding sufficiently long to relieve internal stresses and then slowly cooling. Preheating for Welding - Recommended temperature range for preheating steels and alloys to precent cracking while welding.
Temperature increases with the carbon content.
Spherodizing - Heating to just below AC 1 sufficiently long for for the cementite constituent of pearlite to change into globular form. May take many hours to complete.