Everyone knows that vacuum furnaces are mainly used to process metal materials. Many metal materials are processed at high temperatures or used for other production. So is there a certain type of metal material that cannot be heat-treated in a vacuum furnace?
1. In order to prevent volatilization of alloy elements at high temperatures, high-purity nitrogen is usually filled at high temperatures to maintain partial pressure, and nitrogen-filled cooling is generally used when cooling. Therefore, such materials should not be processed in a vacuum furnace.
2. Carbon steel. From a cost point of view, carbon steel prices are lower, and the price of finished parts is lower. Vacuum furnace processing is really a waste, unless high-profit workpieces or workpieces have no machining allowance, it is a stopgap measure when the surface quality is demanding.
3. Some materials (workpieces) that use special processes. For example, in order to obtain the best mechanical properties, some workpieces require bainite, which is generally achieved by austempering, which is difficult to achieve in a vacuum heat treatment furnace; another example is T10 steel, which requires high hardness and low deformation, which is generally achieved by water quenching and oil cooling. Although the vacuum furnace can be used for high-pressure gas quenching to obtain high hardness, the cooling rate is faster and the deformation is greater due to the temperature below the Ms point.