HEAT TREATMENT
FORGING
Commence at 1100oC and avoid working below 950oC.
ANNEALING
Soak thoroughly at 830oC for 4 to 6 hours and slow cool in the furnace.
STRESS RELIEVING
Hold for 1 to 2 hours at 650oC and cool slowly.
HEATING & SOAKING
Salt Bath Procedure
Pre-heat to 400oC and hold for 1 hour per inch of ruling section. Remove to Neutral
Salt Bath operating at 850oC and soak for 15 minutes per inch with a minimum of 20
minutes. Raise to 1060oC and hold for 10 minutes or 7 minutes per inch, whichever is
greater.
QUENCHING
Quench in Salt at 540oC, allow to equalise and cool in still air.
TEMPERING
Soak at temperature for 1 hour per inch of ruling section or 2 hours, whichever is
longer. A second temper is essential and a third beneficial. |