The advantages of vacuum furnace performance are significant

     The advantages of vacuum furnace performance are significant

The vacuum furnace, as the name implies, is in a vacuum in the furnace, so it avoids many other types of coal burners.
Eliminating the oxidation and decarburization of the surface of the workpiece during the heating process, the cleaning surface of the non-metamorphic layer can be obtained. That only when grinding mill side of cutting tools (such as twist drill grinding after make direct exposure to edge) of the decarburization layer of the grooved surface cutting performance greatly improved relations.
No pollution of the environment, no three waste disposal.
The measurement of furnace temperature and the accuracy of monitoring are obviously improved. Indicated value of thermocouple temperature and furnace temperature reached plus or minus 1.5 ° c. But in different parts of a large number of artifacts in the furnace temperature difference is bigger, if USES the rarefied gas forced circulation, can still be controlled within + / - 5 ° c temperature difference.
High degree of electromechanical integration. On the basis of improving temperature measurement and control accuracy, the workpiece movement, air pressure adjustment, power adjustment, etc., can be programmed in advance, and the hardening and tempering are done by step.
The energy consumption is significantly lower than the salt bath furnace. Modern advanced vacuum furnace heating chamber is made of high quality insulation material of insulation walls and barriers, electric energy can be highly focused on indoor heating, energy saving effect is remarkable.

The characteristics of the vacuum furnace temperature field

The characteristics of the vacuum furnace temperature field

The heating element of a vacuum furnace is generally round. The heat transfer in a vacuum is only radiation, no conduction and convection. There are three modes of conduction, convection and radiation in non-vacuum heating, and the convection and conduction are different from normal furnace (conventional pressure).
The pressure is less than 1 x 105Pa (absolute pressure, the approximate work pressure of the normal furnace). Working pressure close to the vacuum (pa) 2, the convection and conduction effect basic does not exist, workpiece temperature is slow, especially below 600 ℃ heating, heating more slowly, the temperature of the workpiece temperature thermocouple temperature control has certain hysteresis.
The vacuum furnace temperature uniformity measurement is different from ordinary furnace, when measuring the need to guarantee the normal work of the furnace under the condition of vacuum and pressure rise rate, can correct determination of furnace temperature. Because, unlike ordinary furnace, vacuum furnace heat transfer of actual temperature measurement process shows that the control thermocouple temperature at the beginning of the heat preservation and the effective heating area measuring thermocouple temperature difference is bigger. In vacuum condition, temperature deviation in the normal heat preservation time of the effective heating area can reach + / - 5 ℃, meet the needs of the process.

High temperature vacuum furnace

High temperature vacuum furnace

High temperature vacuum furnace refers to the vacuum furnace temperature above 1500 ℃, vacuum high temperature furnace is equipped with infrared thermometer, temperature up to 2500 ℃ and temperature control can be obtained. Vacuum furnace according to the temperature range is divided into low temperature furnace (below 650 ℃), medium temperature (650 ℃ -- 1500 ℃), high temperature furnace (above 1500 ℃).
High temperature vacuum furnace can be used for used for cemented carbide sintering, powder metallurgy and other industries, can also be used for research and development department of scientific research test, high temperature vacuum electric furnace structure affects the balance of furnace temperature, vacuum furnace for many years production experience, our company the reasonable structure of furnace body, temperature balance is good, the vacuum furnace heating correlation even, high temperature vacuum furnace, furnace temperature in good balance.

How to control the heating of molybdenum wire furnace

How to control the heating of molybdenum wire furnace

Temperature coefficient of resistance of tungsten and molybdenum materials is opposite bigger, low-temperature resistance is small, therefore made of tungsten and molybdenum materials do resistance furnace heating element in the process of cold heat, if do not use appropriate control method to produce excessive current and damage to equipment.
At present, the main component of the voltage and current control in the heating and insulation of the electric furnace is the thyristor, the fatal defect of silicon controlled is the overcurrent and the over-voltage difference.In tungsten molybdenum wire of electric furnace, the wire resistance rate at low temperatures is small, easy to produce the flow, so how to guarantee under the premise of the production process to avoid appear over current at low temperatures is of vital importance.According to many years' research and engineering practice of the author, the temperature coefficient of resistance of the larger tungsten molybdenum wire of electric heating can use manual piecewise constant pressure heat up, automatic segmentation pressure limiting temperature and pressure limiting current limit of the double closed loop heat three methods, but can not only meet the current and can meet the requirements of heating process.
Furnace in the first place at a certain temperature heating rate and the targets set by the first paragraph, because of the furnace and furnace heat absorption and heat diffusion, reaches the set temperature when the heating power and cooling rate balance, electric furnace in the process of thermal insulation, temperature in thermal process control system with proper power to maintain constant temperature control of electric furnace.Then, further increase the temperature of the heating voltage, the heating power of the electric furnace is raised, and the electric furnace enters the next phase of warming.