What is Low Temperature Fusion Welding? The temperature of cryogenic welding

What is Low Temperature Fusion Welding? It is. The kind of welding rod caused in the Han Palace. It's low-temperature and can melt and weld something.

It is also very easy to make solder joints at low temperatures, and it is good if there are many solder joints.

It should be a learning method to create the best aspect, which is very connotative.

Low-temperature welding between copper and copper, according to the choice of temperature, there are several kinds of welding material selection for temperature picking.

1. The welding material with a temperature of 179 degrees can be used with the welding wire of Wewelding M51 with the flux of M51-F, the flux of the welding wire with M51-F is tin-based, and the melting point of the soldering is very low, so the impact on copper is minimal.

2. The welding materials with a temperature of about 600-700 degrees can be welded with phosphor copper, such as 202b or 202a phosphor copper or silver phosphor copper wire.

3. High silver welding wire with a temperature of about 700 degrees, such as 45% silver, has good fluidity and bright welds.

1. The welding rod materials used are different. The electrodes used in high-temperature soldering are solder rods that add silver, antimony, or lead to a solder alloy. The electrode used in low-temperature solder is a solder rod formed by adding bismuth, indium, and cadmium to the solder alloy.

2. The scope of application is different. High-temperature solder is mainly used for component assembly that does not change during motherboard assembly; Low-temperature solder is mainly used for the assembly of parts with low heat resistance, such as microelectronic sensors.

3. The temperature is different. The actual operating temperature of high-temperature soldering is above 220 degrees, and the actual operating temperature of low-temperature soldering is below 200 degrees.

The principle of welding is different from the principle of melt welding: it refers to the fact that the filler material (such as welding wire) and the matrix material of the connection area of the workpiece are heated together to a melting state, and a molten pool is formed at the junction, and the liquid metal in the molten pool is cooled and solidified to form a firm welded joint, so that the separated workpiece is connected as a whole. Principle of pressure welding:

Commonly known as solid-state welding, it is a welding process that produces plastic deformation on the separated metal bonding surface to be welded under the action of pressure (or simultaneous heating) to make the metal connection a whole. The principle of brazing: It is a welding method that uses the metal with a lower melting point than the welding metal as the brazing metal, heats the brazing metal and the workpiece together to the melting state of the brazing metal, and sucks it into the solid intermittent with the help of capillary action, so that the brazing metal and the solid working surface are connected into a whole by the mutual diffusion, dissolution and chemical combination of atoms.

2. The object of welding is not the same: 1. Fusion welding: suitable for low-carbon steel weldments. The heat-affected zone is narrow, less harmful, and can be used directly after welding; For carbon steel and low-alloy steel weld penetrates, normalizing can be carried out after welding to refine the grain and improve the mechanical properties.

2. Pressure welding: suitable for many types of weldments. 2) Seam welding is mainly suitable for thin plate welding of oil drums, cans, radiators, aircraft and automobile fuel tanks.

3) Projection welding is mainly used for welding stamping parts of low carbon steel and low alloy steel. 4) When butt welding, the end faces of the two workpieces are in contact with each other, and they are welded along the entire contact surface after being heated and pressurized by the resistor. 3. Brazing is mainly used in welding instruments and conductive components that work at room temperature with little force.

The strength of the joints in soldering is not high.

Fusion welding. It refers to the welding process in which the welded joint is melted under the action of high temperature.

Because the welded workpiece is tightly pressed together, the hole will be mixed without pressure under the action of temperature field, gravity, etc. After the temperature is lowered, the molten part is condensed, and the two workpieces are firmly welded together to complete the welding method. Due to the high-temperature phase change process inherent in the welding process, a heat-affected zone is created in the welding area.

Solid state welding is the opposite of fusion welding, which does not have the melting of metal.

Classification: 1. Gas welding.

The combustible gas used in gas welding is the same as gas cutting, mainly acetylene and liquefied petroleum gas.

propane, butane, propylene, etc.) and hydrogen, etc., oxygen is a combustible gas.

Welding wire for gas welding.

It plays the role of filler metal, and forms a weld metal together with the molten base metal during welding. Therefore, it should be based on the chemical composition and mechanical properties of the workpiece.

Select the corresponding composition or performance of the welding wire, sometimes from the welded plate.

The strip cut on is used as welding wire.

2. Folded plasma arc welding.

Plasma arc welding is also a kind of non-melting electrode arc welding, in which the plasma arc is formed by free arc compression, and the ridge is called the transfer arc. Its ionic gas is argon, nitrogen, helium or a mixture of the two. The energy of the plasma arc is concentrated, the temperature is high, and the flame flow velocity is large.

These properties make plasma arcs widely used in welding, spraying, and overlaying.

Answer: Fusion welding: the workpiece to be welded is locally heated to melting, and the components are connected together by forming a weld after condensation.

Including arc welding, gas welding, electroslag welding, electron beam welding, laser welding, etc. Fusion welding is a widely used welding method, and most of the low carbon steel and alloy steel are welded by fusion welding. Special fusion welding can also weld non-metals such as ceramics and glass.

Depending on the specific welding material, it is generally necessary to consider preheating before welding, heat preservation after welding, and avoid welding at the tuyere.

Low-temperature steel has good weldability, and the key to welding is to ensure the low-temperature toughness of the weld and coarse grain area. At low temperature, because the steel decreases with temperature, the material becomes brittle, and the sensitivity to defects and stress concentration is greater, which is easy to cause low-temperature brittle damage of the product; Ni steel for low temperature has a tendency to temper brittleness.

Low-temperature solder is actually lead-containing solder, and high-temperature solder is lead-free solder.

Low-temperature solder is 63 to 37 in the ratio, 63% in tin, and 37% in lead. The reason why lead is used is to lower the melting point of tin. Because early electronic components were sensitive to high temperatures.

I don't know how many years the solder has been used for this ratio, until more and more people are aware of lead poisoning. The use of leaded solder has now been banned in many European countries.

The melting point of pure tin is very high, but if about 1% silver is added, the melting point will drop, of course, it is still dozens of degrees higher than that of 63 37 tin.

If the tin of 63 37 is 35 yuan, the pure tin is 60 yuan, and the silver is 65 yuan (just an approximation). One of the benefits of silver-added solder is its low resistivity, simply because silver conducts electricity best.

Therefore, high temperature and low temperature are only an environmental protection factor. However, due to the low resistivity of lead-free solder, it is better to use it on sound (sensory effect).

The low temperature tin bars of high-temperature solder DXT-707B are only different in temperature and have certain differences.

**Mobile phone motherboard, screen, cable, buttons, shell, computer accessories, TV accessories and CPU, IC and other components, solder wire, solder block, solder paste, solder slag.

Low-temperature solder is actually lead-containing solder, and high-temperature solder is lead-free solder. This is an incorrect statement, many people are misled by this statement, there is no very clear standard for high and low temperature solder wire, and there are generally the following two conventions to distinguish high and low temperature solder wire.

1. Solder wire with a solid phase point higher than 183 degrees.

2. Solder wire with lead content greater than 85%.

The second method of distinction is clearer, and some foreign companies and some relevant standards have adopted the second method of distinction.