What should I pay attention to when choosing a vacuum furnace

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Vacuum furnaces can be divided into low, medium, high and ultra-high vacuum according to the degree of vacuum. Mainly used for vacuum annealing, quenching, solution treatment, vacuum diffusion welding, vacuum sintering, vacuum brazing, dequality, cleaning, vacuum drying and other processes of workpieces.

Where do I choose a vacuum furnace?

The heating and holding chamber of the vacuum furnace adopts two options of all-metal type and composite type. The all-metal type is composed of heat-resistant stainless steel and molybdenum screen; the composite type is composed of heat-resistant stainless steel, molybdenum screen and carbon felt, mullite fiber or silicic acid. Salt fiber composition. The specific choice depends on the user’s process conditions and requirements for the process environment.

1. Graphite reflective screen: Generally, there are two kinds of hard felt and soft felt used in vacuum furnace, which are suitable for vacuum quenching, tempering and annealing of general steel. High temperature brazing, powder metallurgy and sintering, etc.

2. Metal heat shield: Stainless steel and molybdenum are generally used on vacuum furnaces. The molybdenum reflective screen is suitable for quenching, annealing, high temperature brazing, sintering, etc. of materials with high temperature and high requirements for the furnace environment (such as: high temperature alloys, titanium alloys, magnetic materials, etc.). The stainless steel rice screen is suitable for tempering, low temperature annealing, aging, vacuum aluminum brazing, etc., and some low temperature furnace options.

3. There are several types of heaters such as nickel-chromium wire (belt), molybdenum wire (belt, rod), graphite, etc. The specific choice depends on the high temperature required by the user. There are two heater distribution methods, four-sided heating and omni-directional heating, to ensure the user’s requirements for uniform temperature in the furnace.

4. The cooling system has several types such as Roots blower outer circulation structure, centrifugal fan outer circulation structure, cold wall centrifugal fan inner circulation structure, etc., to meet the requirements of different cooling speeds.
　　
Selection of vacuum degree of vacuum furnace

In the complete set of vacuum furnace equipment, the pumps used in the vacuum system include ion pump + turbo molecular pump + mechanical vacuum pump, turbo molecular pump + mechanical pump, diffusion pump + roots vacuum pump + mechanical vacuum pump, roots vacuum pump + mechanical pump, cryogenic condensation Several types such as pump + mechanical pump are selected according to the ultimate vacuum index. SIMUWU Gehang Vacuum Furnace Company adopts German leybold vacuum and Chinese EVP vacuum brand vacuum pumps to meet customers’ requirements for vacuum pump reliability and cost-effectiveness to the greatest extent.

1. Vacuum quenching heat treatment can be used in a vacuum furnace with a medium vacuum environment (generally limit 4X10-1Pa), using two-stage pumps (fore-stage pumps and roots pumps) such as bearing steel, die steel, structural steel, etc. for vacuum heat treatment.
2. For some products that require high vacuum, such as (vacuum heat treatment or high-temperature brazing of high-temperature alloys, titanium alloys, magnetic materials, etc.. Three-stage pumps (fore-stage pumps, roots pumps, diffusion pumps, etc.) are generally required. The limit of the degree is 10-4Pa.

　　
Choice of instrumentation and temperature control system

Adopt imported intelligent temperature controller, with imported temperature controller and programmable controller as the core, realize the temperature programmable, manual and automatic control. It can realize the automatic control functions of heating, constant temperature, and cooling; it has a process curve storage function, which can store multiple different process curves; it has an adjustable temperature rise and fall speed and an accurate clock function, which can display the actual temperature and the set temperature at the same time. Three kinds of parameters; with PID parameter self-calculation and power-down protection functions. It has complete alarm and protection measures. Equipped with an imported multi-point recorder, it can record the vacuum, pressure, temperature and other process curves of the entire process, which is convenient for process analysis, quality monitoring and production management. Computer control system; use industrial computer and programmable controller as the core technology to program, store and make reports. It can be operated independently by computer, automatic, manual, process programming, etc. SIMUWU brand vacuum furnaces all use internationally renowned brand temperature controllers, such as Eurotherm and Japan Island Electric. All instruments and meters are selected and used in compliance with AMS 2750F standards.
The vacuum gauge can be a highly reliable imported digital intelligent vacuum gauge or a domestic high-quality vacuum gauge to ensure that the vacuum degree and temperature control are interlocked to meet the process requirements.

The choice of industrial computer

It is a high-tech control system integrating monitoring, data collection, operation status, report management, etc. on multiple vacuum furnaces with industrial computer as the core. It has two working modes: manual and automatic. The user can choose the full manual working mode or the mode of group control of multiple industrial computers. SIMUWU vacuum furnace adopts SIEMENS S7 series PLC processor, equipped with SCADA system to remotely control and use vacuum furnace. Let your vacuum furnace after-sales service worry-free.