Vacuum heat treatment ten big magic weapon

Vacuum heat treatment ten big magic weapon

Vacuum furnace is widely used in modern industrial production, but for his skill in vacuum heat treatment is a lot of people don't understand. Our company is a high technology, strength after induction heating equipment suppliers, is willing to work with everyone together to discuss this problem today.
1. Vacuum furnace active connection parts are all made of type O rubber ring sealing connection, this part is cooled.
2. The vacuum furnace processing of titanium alloy, unfavorable use nitrogen as cooling gas, because titanium and nitrogen reaction at high temperature, forming the golden titanium nitride.
3. Vacuum tempering furnace should have fast cooling device. Cooling water pressure should be greater than 0.2 Mpa, the flow should be adjustable.
4. Vacuum furnace maintenance should be in the condition of vacuum or pure nitrogen inflator, avoid inspiratory when not in use at ordinary times, moisture absorption.
5. The domestic vacuum furnace pressure increase rate should be no greater than 1.33 Pa/h, some enterprises abroad standard Pa 0.67 / h
6. Vacuum heating is given priority to with radiation, should keep distance between artifacts in the oven.
7. In the process of heating workpiece and furnace material will be deflated, resulting in a vacuum.
8. Vacuum tempering, vacuum annealing, vacuum heating of vacuum solid solution treatment and aging temperature generally the same as the conventional heating temperature when processing.
9. The workpiece quenching under a vacuum, vacuum quenching oil should be used, the oil has a lower saturated vapor pressure.
10. The cooling gas: steel generally USES ninety-nine point nine nine five percent purity of nitrogen, nitrogen or argon gas, high temperature alloy with ninety-nine point nine nine nine percent of titanium alloy with ninety-nine point nine nine five percent argon gas.

Vacuum heat treatment furnace by using the characteristics of water under the condition of low pressure has a low boiling point

Vacuum heat treatment furnace by using the characteristics of water under the condition of low pressure has a low boiling point

Vacuum heat treatment furnace to the collected signals, according to the logic judgment, the issue on the system and the control signals of running state for each station. Complete skip transportation, vacuum pump, vacuum switch of each valve, given heating, cooling fan, furnace, inflated, etc.
Fault alarm function: according to the technological requirements, a vacuum furnace brazing furnace temperature display abnormal low (or overtemperature), thermocouple damaged or open circuit fault alarm functions, such as when there is abnormal or fault occurs, the fault alarm signal corresponding to the temperature of the point of failure and the touch screen display signal will appear flashing at the same time, to remind the operating personnel in a timely manner to adjust the brazing furnace temperature and to deal with failure.
Vacuum boiler working principle: using the characteristics of low water under the condition of low boiling point, rapid heating sealing furnace heat medium filled in water, high temperature steam, the heat medium water boiling evaporating out water vapor condenses on the heat exchange tube heat exchange tube in cold water, hot water supply.
Equipment in the process of the test run fails suddenly, corresponding to appear on the control instrument error shows that prompt and voice alarm prompt. Operators can control equipment operation using the troubleshooting chapter of the quick check out what kind of failure, can ask professional rapid troubleshooting, to ensure the normal test. Other environmental testing equipment in use there will be other phenomena, that is about the specific phenomenon, specific analysis and ruled out.
In the high temperature test, such as temperature change can not meet the test temperature, can check the electrical system, one by one. Such as temperature rises slowly, will see the wind circulation system, to see if a driving cycle of damper opening to normal, on the contrary, will check whether the wind circulation of motor operates normally. Such as temperature overshoot as you will need to set the setting of PID parameters. If the temperature rise directly, over temperature protection, then, the controller is out of order, must change the control instrument.

Vacuum heat treatment furnace to enhance the convection heat transfer

Vacuum heat treatment furnace to enhance the convection heat transfer

Vacuum heat treatment furnace of the resistance furnace industry generally by the electric heating element, masonry, metal shell, oven door and oven with mechanical and electrical control system, etc. Heating power from less than a kilowatt to thousands of kilowatts. Working temperature below 650 ℃ low temperature furnace; 650 ~ 1000 ℃ temperature in the furnace; More than 1000 ℃ high temperature furnace. In the high temperature and the temperature in furnace mainly by way of radiation heating. In low temperature furnace to heat convection heat transfer, conceal electric heating element is installed inside the air duct, by forced circulation flow of gas in the fan and to enhance the convection heat transfer. Has room type resistance furnace, pit type, car type, push rod type, step type, muff type and tunnel type. Controlled atmosphere furnace, vacuum furnace, fluid particles, etc are also resistance furnace.
Vacuum furnace masters know starting power vacuum furnace, set the switch control cabinet in the automatic control location. Input the parameters of the vacuum furnace process planning into the computer. Then the workpiece with charging car smoothly away in furnace, oven door closed and locked (cover), to ensure the seal. According to the technological requirements to choose good vacuum furnace and the cooling way of cooling medium and pressure. Press the cycle start button, equipment execution procedures: vacuum heating _ _ cooling automatically. Remember to check whether the system is running normal, if there is any abnormal timely report the captain. In before, we should restore the normal pressure in the furnace, the light is normal after open the oven door (cover). When discharging, should careful operation, workpiece and tooling shall glory hole collision.
Difficult control mainly has two aspects, first, how to take off carbon to the lowest in 15 minutes; Second, according to 15 minutes after the decarburization of the residual oxygen content in liquid steel, aluminum one-time add in position, aluminum DNA can be ensured and the aluminum alloy and can guarantee. In this way, the smelting time can control between 25 to 30 minutes. Otherwise, the vacuum processing time was significantly longer. Smelting in the process of production of ultra-low carbon steel, as the extension of time, the contact between refractory material and steel liquid will lead to carbon steel back, in addition, the amount of ultra-low carbon steel because of the addition of aluminum is larger, a lot of Al2O3 inclusions produce, so the aluminum to join the sooner, the more conducive to Al2O3 inclusions floatation, the more conducive to the process after the operation and improve the quality of our products.

The choice of vacuum heat treatment furnace vacuum furnace heating chamber type

The choice of vacuum heat treatment furnace vacuum furnace heating chamber type

The graphite type screen (hard and soft blanket) :
Applicable to the general steel quenching furnace, annealing furnace, etc. Also suitable for high temperature brazing, powder metallurgy material, ceramic material of sintering, etc.
Metal screen type (mo) :
Suitable for higher environmental requirements in the furnace materials (such as high temperature alloy, titanium alloy, stainless steel, magnetic materials, etc.) quenching, quenching, annealing; High temperature vacuum brazing and sintered powder injection molding products.
Metal screen type (stainless steel) :
Applicable to the tempering, stress relieving, aging and vacuum aluminum brazing furnace at low temperature.
The composite panel type (metal + ceramic fiber or graphite felt) :
Inner surface scouring, use between metal and graphite plate.
The choice of control system
Standard:
To inlet temperature control instrument and the temperature of the programmable controller as the core can be turned into and automatic control, the economy is applicable and reasonable allocation.
The computer control system:
With industrial computer as the core set of process programming, storage, reporting, etc. As one of the single control system. In intuitive, large storage, easy to operate.
Computer group control system:
With industrial computer as the core set of data acquisition, process programming, storage, report management, etc., as one of the many sets of vacuum furnace and other heating furnace of centralized control system.
The choice of the vacuum
General materials (such as structural steel, bearing steel, tool steel and die steel, etc.) of the vacuum heat treatment can be used in vacuum (pa) ultimate vacuum 4 x 10-1.
Higher requirements for materials, such as titanium alloy, magnetic materials, high temperature alloy, stainless steel, etc.) of the heat treatment and brazing, can choose high vacuum (ultimate vacuum for more than 4 x 10-3 pa); Should choose higher vacuum degree of vacuum aluminum brazing furnace 10-4 (pa).

Vacuum heat treatment furnace to enhance the convection heat transfer

Vacuum heat treatment furnace to enhance the convection heat transfer

Vacuum heat treatment furnace of the resistance furnace industry generally by the electric heating element, masonry, metal shell, oven door and oven with mechanical and electrical control system, etc. Heating power from less than a kilowatt to thousands of kilowatts. Working temperature below 650 ℃ low temperature furnace; 650 ~ 1000 ℃ temperature in the furnace; More than 1000 ℃ high temperature furnace. In the high temperature and the temperature in furnace mainly by way of radiation heating. In low temperature furnace to heat convection heat transfer, conceal electric heating element is installed inside the air duct, by forced circulation flow of gas in the fan and to enhance the convection heat transfer. Has room type resistance furnace, pit type, car type, push rod type, step type, muff type and tunnel type. Controlled atmosphere furnace, vacuum furnace, fluid particles, etc are also resistance furnace.
Vacuum furnace masters know starting power vacuum furnace, set the switch control cabinet in the automatic control location. Input the parameters of the vacuum furnace process planning into the computer. Then the workpiece with charging car smoothly away in furnace, oven door closed and locked (cover), to ensure the seal. According to the technological requirements to choose good vacuum furnace and the cooling way of cooling medium and pressure. Press the cycle start button, equipment execution procedures: vacuum heating _ _ cooling automatically. Remember to check whether the system is running normal, if there is any abnormal timely report the captain. In before, we should restore the normal pressure in the furnace, the light is normal after open the oven door (cover). When discharging, should careful operation, workpiece and tooling shall glory hole collision.
Difficult control mainly has two aspects, first, how to take off carbon to the lowest in 15 minutes; Second, according to 15 minutes after the decarburization of the residual oxygen content in liquid steel, aluminum one-time add in position, aluminum DNA can be ensured and the aluminum alloy and can guarantee. In this way, the smelting time can control between 25 to 30 minutes. Otherwise, the vacuum processing time was significantly longer. Smelting in the process of production of ultra-low carbon steel, as the extension of time, the contact between refractory material and steel liquid will lead to carbon steel back, in addition, the amount of ultra-low carbon steel because of the addition of aluminum is larger, a lot of Al2O3 inclusions produce, so the aluminum to join the sooner, the more conducive to Al2O3 inclusions floatation, the more conducive to the process after the operation and improve the quality of our products.

The oil level of vacuum heat treatment furnace heat treatment when the pressure of selection problem

The oil level of vacuum heat treatment furnace heat treatment when the pressure of selection problem

Vacuum quenching furnace in vacuum heat treatment furnace used for oil quenching heat treatment process, under low vacuum pressure and vacuum cooling capacity of quenching oil drops, for some steel, may reach the purpose of quenching. Therefore, before using the vacuum quenching furnace quenching to quenching indoor neutral or inert gas filling the high purity, create constant pressure on the oil, can realize fully quenching of steel and the surface of the light. Can get the same quenching hardness under atmospheric pressure and the minimum surface pressure is called the critical quenching pressure. The characteristics of critical quenching pressure and vacuum quenching oil and is related to the hardenability of steel.
  In the use of vacuum quenching furnace for low hardenability of steel quenching, should choose to air into the oil way after quenching. The oil level of the pressure should be higher than the critical quenching pressure. The general regulation about 5 x 104 pa, but should not be below 1.0 x 104 pa. For intermediate hardenability of steel should be adopted after filling into the oil in this way. On the surface of the oil pressure can be adjusted at about 1.0 x 104 pa, but not less than 5 x 103 pa. Good hardenability steel can take air or air quenching in the form of gas, can be after filling in the vacuum furnace heating chamber into the oil, can also be the first oil after aeration. Take air way when air pressure is available in first (2.5 ~ 5) x 104 pa range selected. In order to prevent and reduce the steam to enter and contaminate vacuum quenching furnace heating room, should choose the higher air pressure, gas should be used in the high purity of neutral or inert gas. After filling, translates to lower gas purity, pneumatic pressure can be lower. Adopt the way of inflatable for quenching is artifacts into the oil are not filling the neutral or inert gas before and after.

Vacuum heat treatment line selection requirements

Vacuum heat treatment line selection requirements

1, the standard configuration; To inlet temperature controller and programmable controller as the core, realizes the programmable, manual and automatic temperature control.
2, the computer control system; With industrial computer and programmable controller as the core process programming, storage, to make statements. Can computer independent operation, automatic, manual, process programming, etc.
3, computer group control system; With industrial computer as the core of many sets of vacuum furnace monitoring, collecting data, operation, report management, etc. As one of the high-tech control system.

A basic overview of vacuum heat treatment furnace

A basic overview of vacuum heat treatment furnace

Two professional vacuum heat treatment of vacuum technology and heat treatment technology that combines an integrated, refers to the whole and part of heat treatment process in a vacuum. Our country could be divided into low, medium and high vacuum and high vacuum. Vacuum heat treatment can achieve almost all heat treatment process, such as quenching, annealing, tempering, carburizing, nitriding, during the quenching process can realize gas quenching, quenching oil, water nitrate quenching, quenching, etc., can also be vacuum brazing, sintering and surface treatment, etc. Vacuum heat treatment furnace thermal efficiency is high, which can realize the rapid heating and cooling, which can realize no oxidation and decarburization, carburizing, can remove phosphorus crumbs on the surface of the workpiece, and has the effect such as degreasing degassing, so as to achieve the surface brightness purification effect. Generally speaking, the processed workpiece in the heating furnace is slow, and internal temperature difference is small, the thermal stress is small, so little deformation. Product qualified rate is high. Can reduce costs, have degassing effect, so as to improve the mechanical properties of the work and life. Good working environment, safety operation, no pollution and no pollution. Be processed workpiece no hydrogen embrittlement risk, to prevent surface of the titanium and refractory metal shell hydrogen embrittlement, stability and repeatability of vacuum heat treatment process. A series of advantages, the development of vacuum heat treatment equipment and technology is more and more attention and applied more and more widely.
General metal materials in the heating furnace in air, due to the existence of oxygen in the air oxidation, water vapor, carbon dioxide and other gases, these gases and metal oxidation is easy to make the heated surface of the metal oxide film or oxide skin, completely out of the original metallic luster. At the same time, these gases react with the carbon in the metal, make its surface decarburization. If contains carbon monoxide and methane gas in furnace, still can make the metal surface carburization. For the chemical nature very lively Ti, Zr and refractory metal W, Mo, Nb, Ta, etc., in the air heating furnace, in addition to generate oxide, nitride, hydride, to absorb the gas and internal diffusion to metal, metal material performance deteriorated badly. The oxidation and decarbonization, carburization, breathe in, and even produce the ills, such as corrosion in a controlled atmosphere furnace or salt bath furnace heating, sometimes hard to avoid. To solve this problem, often in front of the workpiece heat treatment have machining allowance, after the heat treatment process to remove oxidation and decarburization layer, etc.