Vacuum fiber welding heat preservation time

Vacuum fiber welding heat preservation time

Time of heat preservation vacuum brazing is done in the condition of vacuum radiation heating. Although the base material thickness is not big, but after considering the loading furnace brazing joint was part of the cover, not directly by radiant heat, work caused by temperature difference, we under heated to solder the liquidus temperature suspends the heating, and under the temperature of heat preservation for a period of time, its aim is to reduce the temperature of the component gradient, make each part temperature homogenization welding and cutting.
Vacuum cooling due to the silver brazing temperature on silver copper alloy solder melting point, and the timely heat preservation, so at this time of silver and copper alloy has melted into liquid, has a certain liquid. Silver copper alloy for plasma arc cutting electrode solder has good electrical conductivity, brazing wettability, and good ability to fill is the numerical control plasma arc cutting electrode ideal solder. Trial, we will first component precooling below the melting point solder, n2 gas filling fast cold again, in order to ensure good between components, thus obtain satisfactory brazing quality.
The numerical control plasma arc cutting electrode after vacuum silver brazing, use in good condition. Import plasma arc cutting electrode using cutting from the plasma arc cutting electrode weld brazing component metallographic image is 300 m, and the use of vacuum silver brazing cutting distance has reached more than 500 m, has been applied in some domestic key enterprises, is gradually replace imports, widespread high praise. From the use of cylinder head bolt, reduced the premature failure of the bolts, such as the bolt fracture or fatigue, etc.). Look from the site conditions to improve the working environment, make originally the lampblack diffuses, ground of the condition of the oil is fundamental improved.

Vacuum brazing technology advantage is introduced

Vacuum brazing technology advantage is introduced

Vacuum brazing technology since 40 s, has become a very promising welding technology. First appeared in the electronics industry in the brazing of copper and stainless steel parts, and then applied to the aviation industry, nuclear industry, started in 1959 is applied to the manufacture of stainless steel plate-fin heat exchanger. Now, they are widely used in air separation equipment, petrochemical equipment, engineering machinery, cars, boats and home appliance industries of plate-fin heat exchanger and cooler.
Because the vacuum brazing technology has incomparable advantages, so in the developed countries in the world get rapid development and wide application. Its advantages are as follows:
1. Vacuum brazing, because no soldering flux, significantly improve the corrosion resistance of the product, from all kinds of pollution, pollution-free processing equipment, has a good safety conditions;
2. The vacuum brazing not only save a lot of expensive metal soldering flux, and without complex flux of the cleaning process, reducing the production cost;
3. The wettability of vacuum brazing filler metals and liquidity is good, can weld more complex and narrow channel device, vacuum brazing improve the yield of the product, get strong clean face;
4. Compared with other methods, the internal structure of the furnace and fixtures such as long life, can reduce the maintenance cost of the furnace.
5. A lot of material is suitable for vacuum brazing, such as: aluminum, aluminum alloy, copper, copper alloy, stainless steel, alloy steel, mild steel, titanium, nickel, nickel by kang (Inconei) can travel through a vacuum brazing furnace, the designer according to soldering device USES to determine the required materials, including aluminum and aluminum alloy applied most widely.

Vacuum brazing performance of the unit

Vacuum brazing performance of the unit

Vacuum brazing furnace brazing furnace to maintain excellent soldering quality depends on the performance of the vacuum brazing furnace maple group vacuum brazing furnace pump often need to pay attention to don't think that you never turn it off, it will run forever. "If the vacuum brazing furnace maintenance crew at the time, on weekends and holidays shutdown, more economical to do so. Otherwise, if still idling at the weekend, mechanical pump will be stuck and difficult to start again. Our experiment results show that the average winter set in 28 degrees, set in 26 degrees in summer. With this method can save a lot of electricity. Due to the lack of water or overheating: temperature 140. ~ 150. F the above 60 ~ 66 ℃), easy to cause mechanical pump overheating, and noises. Available portable device on a weekly basis to pump vacuum brazing furnace oil filter, check the oil level and take the sample, check the oil quality by feeling and appearance.
A few years ago, we have found that the mechanical pump use high quality oil is more economic. The cost of high quality oil is generally more than three times of industrial oil, and keep the pump clean time is five times the sustainable. A valve should be replaced every three months and spring. Stainless steel spring longer diffusion pump should be removed once a year, to overhaul, including all the cleaning. After the diffusion pump oil contaminated can't vacuum soldering furnace So should check the quality of the oil level and oil once a week. Best high quality silicon oil, such as SW1 - ZKY or a brand. Practice shows that using this oil can keep the degree of vacuum brazing furnace in 10 ~ l0 3-5 torr range, brazing production quite satisfied. Replace the oil can be recycled, the price about 70 yuan, every kilograms and new oil 220 yuan per kilogram.

The characteristics of vacuum brazing furnace is not the same

The characteristics of vacuum brazing furnace is not the same

(1) and electrothermal vacuum brazing furnace for annealing, quenching and tempering heat treatment.
(2) as a result of radiant tube burner, compared with electrothermal, two-thirds fuel costs can be cut.
(3) CO2 emissions compared with electrothermal can be reduced by 40%.
(4) regenerative radiant tube burner improved and radiant tube flange of water so as to realize the large radiant tube flange vacuum seal.

Maintenance of vacuum brazing furnace

                                       Maintenance of vacuum brazing furnace

Continuously operating on a daily basis - with no filler metal with vacuum brazing furnace to various parts of the vacuum brazing furnace, inevitably lead to some vacuum brazing furnace charge fly all the damage to the heating elements and heat shield. If not timely maintenance, vacuum brazing furnace metal deposition, will soon be corrosion damage to the heating element, or produce local overheating, or make the heating system is broken one or more of the phase. That leads to the temperature of the inhomogeneity, in batch vacuum brazing furnace production, this kind of situation is often not noticed. Heating element of repair is the easy, it is not the same as heat insulation screen damage.
If heat insulation screen USES the key persons, as long as the screen with a thin layer of ink stone protection can make the vacuum brazing furnace metal splash damage down to the most. Vacuum brazing furnace metal and graphite surface wetting and bonding, not simply in the form of beads drops roll to the cold of the furnace area. After completion of these particles in a vacuum brazing furnace, also not harm can easily be removed.

The advantages of vacuum brazing

The advantages of vacuum brazing

1. Vacuum brazing, because no soldering flux, significantly improve the corrosion resistance of the product, from all kinds of pollution, pollution-free processing equipment, has a good safety conditions;
2. The vacuum brazing not only save a lot of expensive metal soldering flux, and without complex flux of the cleaning process, reducing the production cost;
3. The wettability of vacuum brazing filler metals and liquidity is good, can weld more complex and narrow channel device, vacuum brazing improve the yield of the product, get strong clean face;
4. Compared with other methods, the internal structure of the furnace and fixtures such as long life, can reduce the maintenance cost of the furnace.
5. A lot of material is suitable for vacuum brazing, such as: aluminum, aluminum alloy, copper, copper alloy, stainless steel, alloy steel, mild steel, titanium, nickel, nickel by kang (Inconei) can travel through a vacuum brazing furnace, the designer according to soldering device USES to determine the required materials, including aluminum and aluminum alloy applied most widely.

The vacuum brazing process

The vacuum brazing process

Brazing temperature is the most main technical parameters of vacuum brazing, conclude that the vacuum brazing temperature is the important basis of the selected the melting point of solder and heat treatment of the brazing standards. Vacuum brazing temperature should be higher than the melting temperature of solder, appropriate to reduce the surface tension of the liquid solder, improved wet and caulking, and make the solder and parent metal energetic effect each other, the strength of the joint progress. At the same time, appropriate temperature is higher than the melting temperature of solder and set aside to meet space, also can prevent due to inaccurate temperature control device, workpiece temperature uneven may cause solder melting bad faults. But brazing temperature can be harmful, it may cause solder high vapor pressure elements evaporation, parent metal grain grew up or burnt, and far effect and cause of solder and dissolution, brittle compound layer and intergranular into such questions, make joint function decline, and may be serious weaken the function of the parent metal.
Generally speaking, the vacuum brazing temperature should be higher than the liquidus temperature of the solder 20 ~ 60 ℃, but on different solder, need solder itself above the liquidus temperature scale is different, sometimes even need to drill under the below the liquidus temperature of the solder
Welding. Solder on strong and parent metal effect each other, because of its branch in the process of caulking attacks constitute a very big change and new alloy, concluded that the brazing temperature should be made up of brazing seam in new alloy on the basis of the melting point. Solder on melting temperature scale wide, because above the solidus temperature for liquid phase, and must have liquidity, so the brazing temperature can also be selected below the liquidus temperature of the solder. About eutectic reaction brazing and soldering temperature only in eutectic reaction temperature slightly.
Thinking to the functions of the parent metal for vacuum brazing welding thermal cycle, the influence of brazing temperature pick it necessary to think about the impact on the function of parent metal, brazing shall be in the parent metal attack intense temperature below that at which grain growth or burnt. Drafting of brazing temperature still need harmony with standards of heat treatment after brazing. Brazing temperature can be selected and material, for example, the temperature of the solid solution treatment temperature, and can choose integration of brazing, heat treatment technology, soldering heat preservation after the completion of direct cooling by heat treatment requirements, within a heat cycle end brazing and heat treatment technology at the same time. During the heat treatment after brazing, selection of heat treatment temperature remelting is best not to make solder attack.

Debugging and testing of vacuum brazing furnace

    Debugging and testing of vacuum brazing furnace

After the full set of device according to the skills requirements, shape and outstanding piece of ground, can according to the following project for debugging and testing.
1, check the project
1) appearance quality view: outer appearance should be flat light, no serious pit and mechanical bruising.
2) primary outsourcing parts specifications, certificate of approval of view: such as vacuum unit, magnetic voltage regulator, electronic potentiometer, feeble temperate-feeble processor, vacuum relay, etc.
2, cold furnace debugging
1) mechanical, pneumatic, electrical linkage debugging, adjust the workpiece transfer handling time 25 s or less, the linkage in the case of a load of 200 kg, three actions should be harmonious stable, accurate.
A. vacuum insulated door is opened or closed moment to 8 S or less.
B. the car into the workpiece to the heating chamber schedule time to 12 to 15 S.
C. the workpiece car increase or reduce travel time to 3 S or less.
D. workpiece car to retreat to the cooling chamber schedule time to 12 to 15 S.
E. carry 200 kg of linkage experiments, the total travel time for 25 S successive action should be harmonious stable, or less accurate.
Debug, 2) gas cooling fan speed 1400 r/min, sensitive, no abnormal phenomenon.
3) the alarm system debugging, and should be accurate, secure.
4) measurement of insulation resistance is greater than or equal to 20000 euro.
5) measurement, vacuum stove cold pressure rise rate near 1.5 Pa/h (combing with carrying out in the hot commissioning).

Vacuum brazing furnace and practical environmental protection

Vacuum brazing furnace and practical environmental protection

1 9 7 for 5 years, have 2 00. More than one generation now used in the vacuum brazing furnace put into production. Vacuum brazing furnace, used for soldering estimates about 10%. A lot of the early products meet the strict requirements of aerospace products, in recent years the trend has been towards general industrial situations. As long as carefully review the benefits of this modern tool, this choice is to is self-evident. Vacuum brazing furnace can produce cleaner, precision machining, metallurgy quality products, there are some did not use a vacuum brazing cannot be made into the final shape. Due to cancel the cleaning after soldering, and lower cost. This method can also be used to produce component combination of many small, low-cost products, instead of using large pieces of material machining or welding pieces together. Vacuum brazing furnace, of course, little harm the environment.