Vacuum furnaces have not been developed for a long time in our country. Because of the high production cost and large one-time investment, their application scope is also limited. The number of vacuum furnaces in developed countries is over 23%, which is basically the same as that in controlled atmosphere furnaces. The development of vacuum furnaces is very fast, the degree of mechanization and the level of technology are higher, and almost all heat treatment of metal materials can be realized. Art. Such as quenching, tempering, annealing, carburizing, nitriding, metalizing and other heat treatment processes, complete gas quenching, oil quenching, nitrate quenching and water quenching.
For tool and die steels vacuum Heat Treatment, when heated in vacuum furnace, the radiation heat transfer is reduced, the heating speed is slow, the parts are heated uniformly, so the deformation is very small. After cooling, the radiation heat transfer is reduced, the heating speed is slow, the heating and tensile strength of parts are obviously increased, and the surface of the parts is in the state of compressive stress. Therefore, the parts have a good comprehensive effect. The fatigue strength life of the parts treated by common salt bath furnace is 2-10 times higher than that of the parts treated by common salt bath furnace.
After vacuum annealing, the surface of heat-resistant steel, stainless steel and other parts is smooth, which improves the corrosion resistance of the surface of the parts and the corrosion ability between grains. In addition, it can realize vacuum surfacing, softening annealing, vacuum coating and so on, which is incomparable with other heat treatment equipment.
After vacuum heat treatment, the tensile strength of 30CrMnSiA and 30CrMnSiNi2A, which are important parts such as high strength bolts, increases, but their plasticity and toughness do not change significantly. The fracture toughness decreases while the impact toughness at low temperature is higher. The working strength is increased by more than 100 times, the impact wear and low temperature tensile life are increased by 1.5-2.4 times and 1.6-3.5 times respectively, which indicates the advantages of vacuum heat treatment.
According to the type of process, vacuum furnace can realize vacuum quenching and tempering, vacuum annealing, vacuum solid solution and aging, vacuum sintering, vacuum chemical heat treatment and vacuum coating, so vacuum furnace can realize complex process that other heat treatment equipment can not handle. With the progress of society and the development of science and technology, it will play a huge role. Therefore, in a sense, vacuum furnace provides guarantee for annealing, quenching, tempering and chemical heat treatment of almost all non-ferrous and ferrous metals.
On 2018-08-08 11:45:46
