Heat Treatment of Irons | Cast Irons | Metallurgy
1. Subcritical Annealing (At 705720°C for 1h/25 mm of Section): ADVERTISEMENTS: It directly converts pearlite to ferrite. Carbides may be present in microstructure resulting in lower ductility. After heating, the castings are furnacecooled at 55°C/h to 345°C, and then aircooled. 2.