Steel Heat Treatment

Steel heat treatment is one of the important processes in tool steel manufacturing. Compared with other processing techniques, heat treatment generally does not change the shape and overall chemical composition of the workpiece, but rather confers or improves the use of the workpiece by changing the internal microstructure of the workpiece or by changing the chemical composition of the surface of the workpiece. It is characterized by an improvement in the intrinsic quality of the workpiece, which is generally not visible to the naked eye. If machining is surgery, heat treatment is internal medicine, representing the core competitiveness of a country's manufacturing industry.

Heat treatment process generally includes heating, holding, cooling three processes, sometimes only two processes of heating and cooling. These processes are interconnected and cannot be interrupted.

Process classification

 Metal heat treatment process can be broadly divided into the overall heat treatment, surface heat treatment and chemical heat treatment of three categories. According to the heating medium, heating temperature and cooling method of different, each category can be distinguished into a number of different heat treatment process. The same metal using different heat treatment processes, can obtain different organizations, thus having different properties. Iron and steel is the most widely used metal in industry, and steel microstructure is also the most complex, so there are many kinds of steel heat treatment process.

Overall heat treatment is the overall heating of the workpiece, and then cooled at an appropriate rate, to obtain the required metallurgical organization, in order to change its overall mechanical properties of the metal heat treatment process. Overall heat treatment of steel roughly annealing, normalizing, quenching and tempering of four basic processes.