Introduction And Safe Operation Of Vacuum Heat Treatment Furnace

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Vacuum heat treatment is a comprehensive technology combining vacuum technology and heat treatment, which means that all and part of the heat treatment process is carried out under vacuum.Vacuum heat treatment furnace thermal efficiency is high, can achieve rapid temperature rise and drop, can achieve no oxidation, no decarburization, no carburizing, can remove the workpiece surface phosphorus chips, and degrease degassing and other functions, so as to achieve the surface bright purification effect.

In China, vacuum is divided into low, medium, high and ultra-high vacuum.At present, the working vacuum degree of most vacuum heat treatment furnaces is 1.33~1.33×10-3Pa.Vacuum heat treatment can realize almost all heat treatment process, such as quenching, annealing, tempering, carburizing, nitride, in the quenching process can realize gas quenching, oil quenching, nitrate quenching, water quenching, etc., can also be vacuum brazing, sintering, surface treatment, etc.Vacuum heat treatment furnace thermal efficiency is high, can achieve rapid temperature rise and drop, can achieve no oxidation, no decarburization, no carburizing, can remove the workpiece surface phosphorus chips, and degrease degassing and other functions, so as to achieve the surface bright purification effect.Generally speaking, the processed workpiece is heated slowly in the furnace, the internal heat difference is small, the thermal stress is small, so the deformation is small.The qualified rate of products is high.It can reduce the cost and degassing, so as to improve the mechanical performance and service life of work.Good working environment, safe operation, no pollution and public hazards.The processed workpiece has no danger of hydrogen embrittance, and the surface of titanium and refractory metal shell can be prevented from hydrogen embrittance. The vacuum heat treatment process has good stability and repeatability.This series of advantages, the development of vacuum heat treatment equipment and process is more and more attention and more widely applied.

General metal materials are heated in an air furnace. Due to the presence of oxygen, water vapor, carbon dioxide and other oxidizing gases in the air, the oxidation of these gases and metals is easy to make the heated metal surface produce oxide film or oxide scale, and completely lose the original metallic luster.The gases also react with the carbon in the metal to decarbonize its surface.If the furnace contains carbon monoxide or methane gas, it will also carbonize the surface of the metal.For the very active Ti, Zr and insoluble metals W, Mo, Nb, Ta, etc., heated in the air furnace, in addition to the generation of oxides, hydrides, nitrous compounds, but also absorb these gases and diffuse to the metal interior, so that the performance of metal materials seriously deteriorate.These oxidation, decarbonization, carburization, inhalation and even corrosion and other ills, in a controlled atmosphere furnace or salt bath furnace heating, sometimes it is difficult to avoid.In order to solve this problem, the usual practice is to leave machining allowance before the heat treatment of the workpiece, and remove the oxidation and decarbonization layer after the heat treatment.

Safe operation of vacuum heat treatment furnace

1. Vacuum heat treatment furnace is an advanced heat treatment equipment which has been greatly developed in recent years. The workpiece is heated and cooled in an ultra-low pressure space.It has the advantages of good quality, energy saving, safety and less pollution.

2. The heating element of the vacuum furnace uses low voltage electricity, but the power supply voltage is still 380V, and the operation still needs safe electricity.

3. When vacuum furnace is manufactured, it should be ensured that there is no gas leakage and water leakage.Vacuum furnace body and furnace cover are sealed with rubber parts, so it needs to be cooled by water partition layer.If the water leaks into the furnace, the temperature of the furnace is very high, and it will cause an explosion.The workpiece treated by vacuum furnace should be cleaned of oil stains on the surface and the oil vapor from quenching oil tank should be avoided from entering the furnace.These oil vapor and air will be mixed to form an explosive atmosphere, once there is an open flame or electricity will produce an explosion.Therefore, the door of the vacuum furnace should be closed after charging, and the furnace can be pumped into vacuum before heating by electrification.

Editor: Frank Lee

Copyright: SIMUWU Vacuum Furnace