Thermal treatment process generally comprises heating, insulation, three processes of cooling, has only two processes of heating and cooling sometimes. These processes are interconnected and cannot be interrupted. Heating is one of the important processes of heat treatment. The heating means of metal heat treatmet are a lot, are the earliest to adopt charcoal and coal as thermal source, and then using liquid and geseous fuel. The application of electricity makes the heating easy to control and has no environmental pollution. These heat sources can be directly heated, or indirectly heated by molten salt or gold, or even floating particles.
Metal heat treatment processes can be roughly divided into three categories: overall heat treatment, surface heat treatment and chemical heat treatment. According to the difference of heating medium, heating temperature and cooling method, each big class can be divided into some different heat treatment processes again. The same metal adopts different heat treatment processes to obtain different structures and thus have different properties.
Annealing is to heat the workpiece to an appropriate temperature, adopt different holding times according to the material and the size of the workpiece, and then slowly cool it. Get organized.