The best heat treatment method, let Kehua tell you
The best heat treatment method, let Kehua tell you
Heat treatment has been known as early as the Stone Age. After several industrial revolutions, heat treatment methods are developing rapidly. Kehua has also been researching and continuously improving the performance of heat treatment equipment, making people more efficient in industrial production. Improve, let me introduce to you today! Heat treatment method - Kehua Heat treatment heat treatment refers to a metal thermal processing process that obtains the expected structure and properties by means of heating, heat preservation and cooling in a solid state. In the process from the Stone Age to the Bronze Age and Iron Age, the role of heat treatment is gradually recognized by people. As early as 770 BC to 222 BC, the Chinese have discovered in production practice that the properties of steel will change due to the influence of temperature and pressure deformation. The softening of white cast iron is an important process in the manufacture of agricultural tools. Process characteristics Metal heat treatment is one of the important processes in machinery manufacturing. Compared with other processing processes, heat treatment generally does not change the shape and overall chemical composition of the workpiece, but changes the microstructure inside the workpiece or changes the surface of the workpiece. Chemical composition that imparts or improves the performance of a workpiece. It is characterized by an improvement in the intrinsic quality of the workpiece, which is generally not visible to the naked eye. In order to make the metal workpiece have the required mechanical properties, physical properties and chemical properties, in addition to the reasonable selection of materials and various forming processes, heat treatment process is often essential. Steel is the most widely used material in the machinery industry. The microstructure of steel is complex and can be controlled by heat treatment. Therefore, heat treatment of steel is the main content of metal heat treatment. In addition, aluminum, copper, magnesium, titanium, etc. and their alloys can also be heat treated to change their mechanical, physical and chemical properties to obtain different performance. Process The heat treatment process generally includes three processes of heating, heat preservation and cooling, and sometimes only two processes of heating and cooling. These processes are interconnected and uninterrupted. Heating is one of the important processes of heat treatment. There are many heating methods for metal heat treatment. The earliest ones used charcoal and coal as heat sources, and more recently, liquid and gas fuels were used. The application of electricity makes heating easy to control and free of environmental pollution. These heat sources can be used for direct heating or indirect heating through molten salt or gold, or even floating particles. When the metal is heated, the workpiece is exposed to the air, and oxidation and decarburization often occur (that is, the carbon content on the surface of the steel part is reduced), which has a very adverse effect on the surface properties of the parts after heat treatment. Therefore, the metal should usually be heated in a controlled atmosphere or protective atmosphere, in molten salt and in vacuum, and can also be protected by coating or packaging methods. The heating temperature is one of the important process parameters of the heat treatment process. The selection and control of the heating temperature are the main issues to ensure the quality of the heat treatment. The heating temperature varies with the metal material to be treated and the purpose of the heat treatment, but generally it is heated above the phase transition temperature to obtain a high-temperature structure. In addition, the transformation takes a certain amount of time, so when the surface of the metal workpiece reaches the required heating temperature, it must be maintained at this temperature for a certain period of time to make the internal and external temperatures consistent and the microstructure changes completely. This period of time is called the holding time. When high-energy density heating and surface heat treatment are used, the heating speed is extremely fast, and there is generally no holding time, while the holding time of chemical heat treatment is often longer. Cooling is also an indispensable step in the heat treatment process. The cooling method varies with different processes, mainly controlling the cooling rate. Generally, the cooling rate of annealing is the slowest, the cooling rate of normalizing is faster, and the cooling rate of quenching is faster. However, there are also different requirements due to different steel types. For example, hollow-hardened steel can be hardened with the same cooling rate as normalizing. Heat treatment method - Kehua The editor is convinced that the heat treatment method will definitely continue to improve with the passage of time, and Kehua will also be ahead of time and innovate all the time. Choosing it is choosing the best heat treatment method!