1. Selection of heating temperature:
Quenching and heating problems are basically not uniform, for example, 40Cr material is heated between 870-830℃. It mainly depends on the size of the workpiece, the quenching method, the distance between the furnace and the quenching bath, and the choice of quenching fluid.
2. Holding time problem:
Select according to the shape of the workpiece, place method, etc.
3 Workpiece loading capacity problem:
The volume of the workpiece is very different among the manufacturers, basically 1KW can not exceed 10Kg, that is, a 105-kilowatt furnace can hold up to one ton of workpiece.
4. The choice of quenching method:
Shaft tube products must be placed vertical to prevent cooling eddy currents. The long shaft workpiece quenching is preferably vertical place into the quenching bath to prevent deformation; other quenching methods can also be used, but the shaft tube must prevent cooling eddy currents.
5. Selection of quench media:
The same material can be used oil, quenching medium, water, salt water, and this is related to the size and shape of the product; the same product (material and shape exactly the same), you can also use a lot of quenching media, which depends on the number of workpiece quenching one time, cooling water temperature, quenching tank cycle and so on. For dry shafts, like material 40Cr, quenched with 3% medium quench, either with water or salt water.
6. Tempering options:
Tempering can lead to poor organization of quenched and tempered products, and the tempering time of the product should not be too long, including heating time and holding time, both too long will cause bad organization.