1. Quenching principle:
Vacuum quenching refers to a heat treatment method that heats and maintains the workpiece to be processed in a vacuum state, and then rapidly cools it in high-pressure cooling gas to harden it. The operation process is usually as follows: put the workpiece into the furnace, evacuate, and start heating when the vacuum reaches 1-10-2Pa. It usually requires preheating to make the workpiece temperature the same as the temperature. When the solid solution temperature is reached, keep it warm. , after the heat preservation is completed, fill the furnace with inert gas at a pressure of 2-10 bar, and use a fan to circulate the cooling gas between the workpiece and the heat exchanger to meet the requirement of rapid cooling from the solid solution temperature, thereby achieving the hardening of the workpiece being processed. Since vacuum high-pressure gas quenching has the advantages of high cooling rate, no surface oxidation or carbonization, good quenching uniformity, small deformation of the workpiece, high production efficiency, low cost, and no environmental pollution, its application is increasing day by day and it has developed quite rapidly. It has become the most eye-catching vacuum heat treatment technology at home and abroad.
2. Quenching characteristics
The best effect of vacuum gas quenching is to obtain the best mechanical properties of the treated parts, which requires both high cooling rate and good cooling properties. A low cooling rate can ensure the hardness of the processed parts, and good cooling uniformity can ensure minimal deformation. Since the vacuum heat treatment of metals and alloys is carried out under negative pressure, it is easy to obtain treatment effects that are difficult to obtain in general atmosphere heat treatment, so that the workpiece has excellent performance.
(1) No oxidation and no decarburization.
(2) Surface purification effect, the surface brightness of the workpiece is good.
(3) Less deformation during heat treatment.
(4) Improve service life.
3. Main application
Mainly used for tools, molds, cutting tools and mechanical parts with relatively high technical requirements and complex shapes. The materials processed include W18Cr4V, W6Mo5Cr4VZ, Cr12, Cr12MOV, gCrsi, CrWMn, 3CrZWS, GCr15, 40Cr, 9Cr13, 3Cr13, 50CrV, 60512, 17-4PH, 15-7MOPH, ICr13NigTs, QBeZ and other materials. At the same time, machined or welded aluminum alloys, titanium alloys, etc. with complex shapes and high dimensional accuracy requirements also have the advantage of maintaining dimensional stability that other heat treatments cannot match.
