The basic principle, characteristics and use of electron beam welding
29 Jun 2019
The basic principle, characteristics and use of electron beam welding Electron beam welding utilizes a high-speed electron beam that is focused in a vacuum to bombard the surface of the weld, causing it to melt instantaneously and form a welded joint. Electron beam welding has the following characteristics: 1) High energy density and strong electron penetration; 2) The welding speed is fast, the heat effect is cancelled, and the welding deformation is small; 3) The vacuum protection is good, the weld quality is high, and it is especially suitable for the welding of living wave metal. Electron beam welding is used to weld low alloy steel, non-ferrous metals, refractory metals, composite materials, dissimilar materials, etc., thin plates and thick plates. It is especially suitable for welding thick parts and welding parts requiring small deformation, using devices in vacuum, precision micro-devices, etc.
What is the basic principle of laser welding
21 Jun 2019
What is the basic principle of laser welding? Laser welding uses a focused laser beam as an energy source to bombard the heat generated by the workpiece for welding. Laser welding has the following characteristics: 1) The laser beam has high energy density, the heating process is extremely short, the welding point is small, the heat affected zone is narrow, the welding deformation is small, and the weldment dimensional accuracy is high; 2) It is possible to weld materials that are difficult to weld by conventional welding methods, such as welding refractory metals such as tungsten, molybdenum, niobium, and zirconium; 3) It is possible to weld non-ferrous metals in the air without the need for additional protective gas; 4) Laser welding equipment is more complicated and costly. Laser welding can weld low-alloy high-strength steel, stainless steel and copper, nickel, titanium alloy, etc.; dissimilar metals and non-metallic materials (such as ceramics, plexiglass, etc.); currently used in...
The type of resistance welding and the applicable occasions
15 Jun 2019
Resistance welding is a welding method in which a current is passed through a resistance heat generated between a workpiece and a welding contact surface to heat the weldment to a plastic or partially melted state, and then pressure is applied to form a welded joint. Resistance welding is divided into three types: spot welding, seam welding and butt welding. (1) Spot welding: the weldment is pressed between the two columnar electrodes, and is heated by electricity to melt the weldment at the contact to form a nugget, then power off, and solidify and crystallize under pressure to form a dense joint. . Spot welding is suitable for welding thin plates (laps) and steel bars up to 4 mm, and is widely used in the production of automobiles, airplanes, electronics, instruments and daily necessities. (2) Seam welding: Seam welding is similar to spot welding except that a rotating disk electrode is used instead of the column electrode. The stacked workpieces are energized between the discs and f...
What are the characteristics of electrode arc welding
10 Jun 2019
What are the characteristics of the composition of low carbon steel welded joints and the microstructure and properties of metals in various regions during electrode arc welding? (1) The welded joint consists of weld metal and heat affected zone. 1) Weld metal: When welding, the temperature at the weld is above the liquidus, and the base metal and the filler metal form a common molten pool, which becomes an as-cast structure after condensation. During the cooling process, the liquid metal crystallizes from the fusion zone toward the center of the weld to form a columnar crystal structure. Since the electrode core and the coating have alloying effect during the welding process, the chemical composition of the weld metal is often superior to that of the base metal. As long as the electrode and welding process parameters are selected reasonably, the strength of the weld metal is generally not lower than the strength of the base metal. 2) Heat-affected zone: The area where the metal on bot...
Classification and advantages of arc welding
31 May 2019
A fusion welding method using an electric arc as a heat source is called arc welding. Can be divided into manual arc welding, submerged arc automatic welding and gas shielded welding. The biggest advantage of manual automatic welding is that the equipment is simple, flexible and convenient to apply, wide in application, and can weld various welding positions and straight seams, ring seams and various curve welds. Especially suitable for welding in the case of constant operation and welding of short welds; Submerged arc automatic welding has the characteristics of high productivity, good weld quality and good working conditions; Gas shielded welding has the characteristics of good protection effect, stable arc and concentrated heat.
What is brazing
25 May 2019
What is brazing? How is brazing classified? What are the characteristics of the brazed joint form? Brazing is to use a metal whose melting point is lower than that of the base material as a brazing material. After heating, the brazing material melts, the weldment does not melt, the base material is wetted by the liquid brazing material, the joint gap is filled and the base material is mutually diffused, and the weldment is firmly fixed. Connected together. Brazing is divided into soldering and brazing depending on the melting point of the solder. (1) Soldering: The soldered solder has a melting point of less than 450 ° C and a low joint strength (less than 70 MPa). (2) Brazing: The brazing filler metal has a melting point higher than 450 ° C and a higher joint strength (greater than 200 MPa). The bearing capacity of the brazed joint is related to the size of the joint face. Therefore, brazing is generally lap joints and kits to compensate for the lack of brazing strength.