Cooling and heating methods for stainless steel forgings

According to the different cooling speed, there are three cooling methods of stainless steel forgings: cooling in the air, cooling speed is faster; The cooling speed is slow in the sand; Cooling in the furnace, cooling rate is the slowest.
1. Cooling in the air. After forging, stainless steel forgings are directly placed on the floor of the workshop for cooling in single pieces or in piles, but not on the wet ground or the metal plate, nor in the place with draughting, so as to avoid uneven cooling or local rapid cooling causing cracks.
2. Cooling in the dry ash and sand pit (box), the general steel sand temperature should not be less than 500℃, the surrounding ash and sand thickness is not less than 80mm.
3. Cooling in the furnace, stainless steel forgings are directly put into the furnace for cooling after forging. The temperature of steel parts in the furnace should not be lower than 600-650℃, and the temperature of stainless steel forgings in the furnace is equivalent to that of the furnace. Because the cooling rate of stainless steel forgings can be controlled by furnace temperature adjustment, it is suitable for the post-forging cooling of high alloy steel, special alloy steel forgings and large stainless steel forgings.

Stainless steel forgings induction surface heating methods have two kinds: continuous mobile and fixed, continuous moving method is the sensor or stainless steel forgings heating and moving in the process of cooling and quenching followed by the edge. And the fixed stainless steel forgings heating quenching surface in the sensor, the sensor and stainless steel forgings have no relative movement, to be heated to the temperature after the spray cooling or the stainless steel forgings into the whole cooling medium quenching.
Fixed heating is limited by the power of the equipment. Sometimes, in order to heat the stainless steel forgings that exceed the power limit and reach a certain depth of the hardened layer, repeated heating or pre-heating to 600℃ is used.
Stainless steel forgings induction heating using continuous mobile heating is more common, high frequency quenching heating is usually fixed sensor and stainless steel forgings mobile. Medium frequency and power frequency heating, often to sensor movement, stainless steel forgings can also be rotated when needed. The inductor is mounted on the moving table of the quenching machine.
Quenching temperature depends on the selection of power and moving speed, because the continuous moving heating area is small, the application range of stainless steel forgings is more extensive, so at present, in the induction heating of stainless steel forgings at home and abroad, the general use of high power induction heating method of low.