How does a vacuum brazing furnace operate?

How does a vacuum brazing furnace operate?

There are many kinds of vacuum furnaces, and the scope of application is very wide, vacuum furnace has vacuum brazing furnace, so how to operate the vacuum brazing furnace? Let's talk about the vacuum furnaces.
Before you open the stove, you should check the water, electricity, gas and so on.
Before placing the material, you should check the heating room, ask for the clean, not the clutter, the material you put in should be dry and clean, no water stains and oil stains.
When the loading is complete, push the button to the door, then open the device.
4. Vacuum, when more than 1000 mpa, monitoring J2 lights up, then to Cairo, pump, if not up to par, roots pump is not open, button there will be no response.
Through the introduction of vacuum furnace, it is believed that the operation of vacuum brazing furnace is very clear.

Vacuum brazing furnace structure

Vacuum brazing furnace structure

Vacuum brazing furnace is processed workpiece heat treatment of a large equipment, can undertake vacuum annealing, vacuum limitation as well as vacuum brazing and so on heat treatment processing. Vacuum brazing furnace can write a variety of different applications, can also control and write hundreds of curve of heat treatment, its temperature control zone can be roughly divided into before and after the up, down, left, right, and the six partitions, vacuum brazing furnace installation has a single point and multi-point temperature protection device and temperature recorder, and the uniformity of furnace temperature can be controlled in the range of fluctuation of 3 degrees Celsius, in addition, also strong cooling device with high flow, high purity nitrogen. The vacuum brazing furnace has high efficiency and high furnace quantity.
Vacuum brazing furnace is mainly used in aluminum vacuum brazing, titanium alloy, stainless steel, high temperature alloy, hard alloy and nonferrous metal brazing, and die steel, stainless steel, high speed steel and bearing steel materials such as vacuum tempering heat treatment.
Vacuum brazing furnace structure:
Vacuum brazing furnace consists mainly of heating room, vacuum chamber, pump system, control system and heat exchanger. The pump system consists of the maintenance pump, mechanical pump, diffusion pump, and the rotz pump. Valve consists of pneumatic valves such as high valve, front stage valve, maintenance pump valve and by-pass valve. The heating chamber consists of heating chamber shell, heater, reflector, insulation, hearth and electrode.
When the vacuum brazing furnace works, the mechanical pump, the diffusion pump, the pump and the front stage valve, the pump valve, and the pump valve begin to vacuum in the diffusion pump. When the vacuum in a vacuum brazing furnace reaches a certain value, the rotz pump, the bypass valve starts and the front valve closes, and the vacuum chamber is evacuated. When the diffusion pump is heated to the specified temperature, the bypass valve closes, the high valve and the front valve open. The heat treatment process can be carried out after the vacuum chamber is vacuum and the vacuum degree is required.

Vacuum brazing furnace and furnace design

Vacuum brazing furnace and furnace design

1, furnace design
The part of the furnace is the main part of the vacuum brazing furnace, which consists of two parts: the hearth and the furnace door. The furnace tube is made up of double deck steel plates, which contain furnace bile (that is, the heating room). Furnace tube wall and the outer wall made from stainless steel and carbon steel, respectively, in the middle is a water jacket, on top of the furnace tube is equipped with water cooling electrode introduction, introduce thermocouple, cooling pipe, pneumatic system and other devices. The door adopts the oval standard head, the sealing head is also double water jacket structure, can open before and after, the door has glass observation window, convenient to install and exit the work piece. In order to guarantee the vacuum inside the furnace, the shaft and the furnace door are sealed with the dovetail seal groove, "O" type rubber ring.
Second, furnace design
Furnace urchin is made up of hexahedron (four sides), which is placed on the rails of the furnace and the front and back of the furnace door, which can be easily changed. All heating surfaces are made up of stainless steel frames and five-layer reflecting screens. The first screen is a molybdenum screen, while the other four layers are stainless steel. The heating element is made up of several molybdenum wire, which is insulated by the 95-porcelain and is fastened to the frame by the stainless steel connection column. In order to reduce the warp distortion caused by high temperature thermal expansion, the reflection screen is made up of several pieces. No use nickel chrome in the device as a heating element, nickel chromium heating bill of materials from temperature indicators, it can completely meet the requirements, but under the high vacuum high temperature, volatile nickel chromium element, particularly chromium element belongs to the low vapor pressure material, contaminate furnace, affect the solder and the surface element content, lead to welding seam mechanical property in the heat treatment performance degradation.

Brazing technology of classification and what are the advantages?

Brazing technology of classification and what are the advantages?

Brazing is one of the three welding method, including fusion welding, brazing and bonding of the three. Brazing process is mainly to use than the weld metal of low melting point metal solder, and then heated to a temperature higher than the weldment and filler metals solder, below the melting temperature of the weldment, then using liquid solder wetting welding pieces of metal, fill the joint clearance and mutual diffusion and base metal, so as to realize a method of connecting the weldment. So compared with other welding methods, brazing process advantages what?
1, when soldering, solder melts, and weldment won't melt, and the temperature of the welding with the different choice of solder, and at room temperature to nearly large areas of the parent metal melting temperature change inside. In order to avoid the base organizations, as well as the change of the performance, you can choose to brazing filler metals, which have lower melting point and welding is no choice.
2, at the time of brazing, welding is often a whole heating or around the brazing seam for uniform heating of large area, therefore, relative distortion of welding and brazing welding head are much smaller than welding residual stress, it is also to ensure the precision of welding.
3 are heavily dependent on liquid filler metals, brazing seam automatically fill the gap after frozen, so as long as the solder, flux and brazing methods selection of good, can mass or many brazing seam welding at the same time or continuous brazing, productivity is very high. In the process of brazing rarely because of the accessibility of the weld structure, and open sex.
4, because the soldering reaction only in parent material of a few microns and even the following interface to dozens of micrometers, so, generally does not involve the deep structure of parent metal, and therefore, more suitable for dissimilar metal stents, and even nonmetallic and nonmetal, the connection between the metal and nonmetal, it is can't do welding method.
5, brazing seam strength and heat resistance were lower than the base metal, and in order to make up the lack of strength, often by increasing the overlap area to solve the problem, so the braze welding head will be more samples of the lap joint methods to increase the weight of the structure, therefore, is more brazing materials.

The vacuum brazing furnace main

The vacuum brazing furnace main 

It is mainly used for aluminium parts brazing production under the protective atmosphere. Mainly include solder spray machine, electric heat drying furnace, brazing furnace, water-cooled air cooling device, the atmosphere control system and automatic control system, etc. Suitable for parallel flow condenser, cascading evaporator and car tank mass production of aluminum alloy heat sink, etc.
Main features:
1, spray device has the advantages of simple structure, easy to use.
2 in furnace, drying furnace circulating wind speed is high, large heat capacity, ensure the workpiece drying thoroughly.
3, brazing furnace reasonable partition fine, high precision temperature control, furnace temperature uniformity is good, energy-saving effect is remarkable.
Production line 4, the consummation control system integration, intelligent, control, alarm, protection system to ensure the safe and reliable operation of the production line.
More than 5, range, high precision of oxygen analyzer for real-time accurate measurement in furnace atmosphere provide advanced means.

Understand the high requirements of the high temperature vacuum furnace

Understand the high requirements of the high temperature vacuum furnace

High temperature vacuum furnace ironmaking automation is designed to make production process optimization, produce stable quality products and improve the process operator working conditions, this requires the technical and economic aspects of productive rationalization measures, in the process of ore smelting discount, physical and chemical changes very difficult to control the difficult measurement.
More and more high mechanization degree of high temperature vacuum furnace, vacuum environment was does not have other forms of sintering (when the furnace vacuum degree is 1.3 * 10-1 PASCAL, remaining in the furnace gas purity argon 99.99987%); Vacuum sintering can make material before a liquid particle oxidation film completely ruled out, so as to change a good wettability of the liquid with carbide phase, to improve the alloy organization structure, improve the performance of alloy. Due to the vacuum press billet pore reduced the amount of gas in steel rolling workshop push by the steel type heating furnace of continuous development to all kinds of stepping type furnace, roller hearth furnace, furnace, chain furnace, etc.
Some within the chamber furnace heating shaped blank in the past, now change in annular furnace heating, productivity had the very big enhancement. The use of the electronic computer, the stove from loading assumed, paragraphs in the furnace temperature control, fuel and air traffic control, automatic control, furnace pressure until the steel material on time and discharging program operation, are given by computer control values, and be able to adopt the optimal control of the furnace condition, on the temperature of the steel material and the temperature difference at very accurately.

How to determine the cooling speed of vacuum brazing furnace parts

How to determine the cooling speed of vacuum brazing furnace parts

Weldment cooling is done at the end of the soldering heat preservation, but the rate of cooling is have effect on the quality of the joint. Cooling speed too slow, may cause the grain growth of parent metal, solder with parent metal interaction time growth, leading to excess of parent metal to dissolve in the solder, produce corrosion defects; To speed up the cooling speed, which is beneficial to refine brazing seam organization, thus improve the joint strength; But cooling speed too fast, may make the welding crack due to excessive internal stress formed, may also be due to the brazing seam rapid solidification doesn't make the gas evolution and formation porosity. Therefore specific to determine the cooling speed, must be combined with weldment size, by synthetically considering all kinds of factors such as parent material types and solder.