Heat treatment process generally includes heating, heat preservation and cooling, sometimes only heating and cooling. These processes are interlinked and uninterrupted. Let’s study the detailed processes with Shandong No2 Machinery Co. Ltd..

Heating

When metal is heated, the workpiece is exposed to air. Oxidation and decarbonization (i.e. the carbon content on the surface of iron and steel parts decreases) often occur, which is not good to the surface performance of the parts after heat treatment. Therefore, metals should be heated in controllable or protective atmosphere, molten salt or vacuum. Coatings or packaging methods can also be used for protective heating.