Heat treatment of the cooling process control

1 in order to ensure that the cooling effect of heat treatment, normalizing the workpiece during cooling should be hung from the furnace under the air cooling, block pad high artifacts, ventilation around to retain a certain space. The temperature of the cooling after tempering furnace charging when the workpiece should be controlled at 300 ℃. When 2 of quench, should start the cooling medium ( Water or oil) The circulatory system. Artifacts to and fro to increase the cooling effect after immersion medium, medium fluid amount found enough should fill in a timely manner. 3 when the workpiece immersion oil medium should pay attention to fire safety. 4 small quenching, if the cooling groove are too far away from furnace affect the cooling effect, should be temporary use num ( Oil) Trough, to ensure the workpiece into the cooling medium in time after can get proper cooling effect. 5 for high alloy steel ( Such as 3 cr2w8v) After, when high temperature quenching is cracked, it should be precooling once again into the quenching medium, quenching cracks in order to prevent the thermal stress. 6 for the thin and long shaft parts, to reduce the quenching deformation, lateral and straight to the immersion quenching medium, should as far as possible or put on the large flat together immersion medium, in order to reduce deformation. 7 for double liquid quenching workpiece, if there is a groove or cavity, is coming out from the water, net should pour water into the tank after cooling. General tank oil temperature at 150 ~ 200 ℃ ( Artifacts are slightly emit smoke) It is advisable. 8 artifacts must promptly tempering after quenching, re-blows are generally not more than 2 hours.