Welding, also known as welding, is a manufacturing process and technique that uses heat, high temperature, or high pressure to join metals and other thermoplastic materials such as plastics.
Modern welding has many energy sources, including gas flame, arc, laser, electron beam, friction, and ultrasonic waves. Welding can be done in a variety of environments, including in factories, as well as in the field, underwater, and in space. Anywhere welding is done can pose a risk to workers, so proper protective measures must be taken when welding. Potential personal injuries from welding include burns, electric shock, visual impairment, inhalation of toxic gases, and excessive UV exposure.
Welding achieves the purpose of joining in three ways:
1. Fusion welding - The workpieces to be joined are heated to form a partial molten pool, and a weld filler is added as needed to join them.
2. Pressure welding - The welding process requires the application of pressure to the weld and is the processing of various metallic materials and some metallic materials.
3. Pressure welding - The welding process requires the application of pressure to the weld and is the processing of various metallic materials and some metallic materials. 3. Brazing - A metal material with a lower melting point than the base metal is used as a filler metal, and the liquid filler metal is wetted into the base metal to fill the joint gap and then interdiffuse with the base metal to weld. . Suitable for welding various materials as well as welding of dissimilar metals and dissimilar materials.
Classification of welding
Metal welding is classified into three types according to the characteristics of the process: fusion welding, pressure welding, and brazing.
During the welding process, when the atmosphere comes into direct contact with the high-temperature molten pool, the oxygen in the atmosphere oxidizes the metal and various alloy elements. Nitrogen and water vapor in the atmosphere enter the molten pool and form defects such as pores, slag inclusions, and cracks in the weld during the subsequent cooling process, which reduces the quality and performance of the weld.
In order to improve the quality of welding, various protection methods have been developed. For example, gas-shielded arc welding uses argon, carbon dioxide, and other gases to isolate the atmosphere and protect the speed of the arc and molten pool during welding. In addition, in steel welding, ferrotitanium powder, which has a high affinity with oxygen, is added to the electrode. Coating for deoxidization. It protects beneficial elements such as manganese and silicon in the welding rod from oxidation and ingress into the molten pool, and allows you to obtain a high-quality weld after cooling.
Tabletop cold pressure welding machine
A common feature of various pressure welding methods is that pressure is applied during the welding process without adding filler metal. In most pressure welding methods, such as diffusion welding, high-frequency welding, and cold pressure welding, there is no melting step, so there is no problem of beneficial elements in the alloy burning or harmful elements ingressing into the weld. Fusion welding simplifies the welding process and also improves the safety and hygiene of welding. At the same time, the heating temperature is lower and the heating time is shorter than in fusion welding, resulting in a smaller heat-affected zone. Many materials that are difficult to weld by fusion welding can be welded by pressure welding, forming a high-quality joint with strength equivalent to that of the base material.