How many welding methods are there as mentioned Thank you

Classification of common welding methods.

1. Fusion welding. The method of partially heating two welded workpieces until melting to overcome the obstacle of bonding between solids, and then cooling and crystallizing into a single joint is called fusion welding.

According to the different heat sources used, the basic methods of fusion welding can be divided into arc welding, bolt welding, gas welding, thermite welding, electroslag welding, electron beam welding, laser welding, etc.

In the case of fusion welding, protection is implemented in the welding area in order to avoid deterioration of performance caused by the interaction between the hot metal and air in the welding area. There are usually three types of protection methods: slag making, shielding gas and vacuuming. Therefore, the form of protection is often another feature that distinguishes fusion welding methods.

2. Pressure welding. The welded workpiece is subjected to pressure (heated or not heated) measures in the solid state to overcome the influence of impurities such as unevenness and oxides on the connecting surface, so that the spacing between its molecules or atoms is close to the distance between the crystal lattices, so as to form an inseparable joint A type of welding method is called pressure welding, also known as solid phase welding. In order to reduce the deformation resistance of the material during pressurization and increase the plasticity of the material, pressure is often applied during pressure welding.

New welding equipment.

According to the different welding energies applied, the basic methods of pressure welding can be divided into resistance welding (including spot welding, seam welding, projection welding, butt welding), friction welding, ultrasonic welding, diffusion welding, cold pressure welding, ** welding and forging welding.

3. Brazing. The welding method of using some metal with a melting point lower than the melting point of the material to be connected (i.e., brazing metal) as the medium of connection, and using the diffusion between the material and the base metal to connect two welded workpieces together is called brazing. During brazing, it is usually necessary to remove dirt from the surface of the workpiece and increase the wettability of the filler metal, which requires the use of flux.

The brazing metal must also be heated to melt the filler metal (but the workpiece does not melt).

According to the different heat sources, brazing methods can be divided into flame brazing, induction brazing, resistance furnace brazing, salt bath brazing and electron beam brazing. It can also be divided into two categories: hard brazing (melting point above 450) and soft brazing (melting point below 450) according to the different melting points of brazing metal. Protections are usually required during brazing, such as vacuuming, shielding gas and flux.

Welding type method:

1. Electrode arc welding

Principle - an arc welding method for welding with manually operated electrodes. A stable burning arc established between the electrode and the weldment is used to melt the electrode and weldment, resulting in a strong welded joint. It belongs to the joint protection of gas slag.

Main features - flexible operation; Low assembly requirements for the welded joint; Wide range of weldable metal materials; Low welding productivity; Weld quality dependence (depends on the welder's operational skills and on-site performance).

Application - Widely used in shipbuilding, boilers and pressure vessels, machinery manufacturing, building structures, chemical equipment and other manufacturing and maintenance industries. It is suitable for welding of various metal materials, various thicknesses and various structural shapes (in the above industries).

2. Submerged arc welding (automatic welding):

Principle – The arc burns under the flux layer. A weld is formed by melting the wire, flux, and base metal (weldment) using the heat generated by the burning arc between the wire and the weldment. Slag protection.

Main features - high welding productivity; Welding seam***; Low welding cost; good working conditions; Difficult to weld in a spatial position; High requirements for the assembly quality of weldments; It is not suitable for welding thin plates (when the welding current is less than 100A, the arc stability is not good) and short welds.

Application——Widely used in shipbuilding, boilers, bridges, lifting machinery and metallurgical machinery manufacturing. Submerged arc welding can be used for weldments where the weld can be kept in a horizontal position or the angle of inclination is not large. The thickness of the plate should be greater than 5 mm (burn-through resistant).

Welded carbon structural steel, low-alloy structural steel, stainless steel, heat-resistant steel, composite steel, etc.

3. Carbon dioxide gas shielded welding (automatic or semi-automatic welding):

Principle: Melting electrode arc welding method using carbon dioxide as shielding gas. Atmospheric protection.

Main features - high welding productivity; Low welding cost; Small welding deformation (arc heating concentration); High welding quality; Simple operation; High spatter rate; It is difficult to solder with AC power; Poor wind resistance; Non-ferrous metals that are susceptible to oxidation cannot be welded.

4. MIG MAG welding (molten inert gas active gas shielded welding):

MIG welding principle - an arc welding method that uses inert gas as shielding gas and welding wire as melting electrode. The shielding gas is usually argon or helium or a mixture of them. MIG uses inert gas, MAG adds a small amount of active gas, such as oxygen, carbon dioxide, etc., to the inert gas.

5. TIG welding (tungsten inert gas shielded welding).

Principle - under the protection of inert gas, the arc heat generated between the tungsten electrode and the weldment is used to melt the base metal and the filled welding wire (or without filling the welding wire) to form a welding seam. The electrode does not melt during the welding process.

6. Plasma arc welding.

Principle - with the help of the water-cooled nozzle on the arc constraint effect, obtain a high energy density plasma arc for welding.

Welding technology in industry generally depends on the type of job, in general: 1Manual arc welding, argon arc welding, electroslag pressure welding, flash butt welding, oxyacetylene flame gas welding and cutting, and carbon dioxide protection welding are commonly used in civil engineering for steel structure installation and non-ferrous metal welding.

2.Plastic welding is mostly used for hot melt welding of various engineering plastics, in which plastic bonding should also belong to the welding process. 3. The welding of shipbuilding boilers and various pressure vessels requires higher welding process requirements and stricter technical requirements, on-site operations, and uses special processes such as manual arc welding, argon arc welding, carbon dioxide protection welding, and electroslag welding.

3.There are also ultrasonic welding, first-class welding, etc., which are special welding technologies under special processes, and their uses are limited in actual operations, and they are no longer classified.

The principle of argon arc welding is that the weld is shielded by argon gas, and the oxygen does not oxidize the weld. The welding materials are special welding wires, copper, stainless steel, etc.

The commonly used welding methods are as follows:

1. Linear transport method. When this method of transportation is adopted, the welding rod does not swing horizontally, but moves in a straight line along the welding direction. It is commonly used for butt flat welding of grooves, first layer welding of multi-layer welding or multi-layer multi-pass welding.

2. Straight-line reciprocating method. When welding with this strip method, the end of the electrode swings back and forth along the longitudinal direction of the weld. It is characterized by fast welding speed, narrow weld seam and fast heat dissipation. It is suitable for the first layer of multi-layer welding with large gaps between thin plates and joints.

3. Zigzag transport method. In this method of welding, the end of the electrode is zigzag and moves forward, and stops on both sides for a while. The purpose of the oscillation is to control the flow of the molten metal and obtain the necessary weld width to obtain a better weld formation.

This method of transporting bars is widely used in production, and is mostly used for the welding of thick steel plates, the butt joints of flat welding, vertical welding, vertical welding and the fillet joints of vertical welding.

4. Crescent-shaped transport strip method. When welding with this rod method, the end of the electrode swings left and right in a crescent-shaped shape along the welding direction. The speed of the swing is determined according to the position of the weld, the form of the joint, the width of the weld and the value of the welding current.

At the same time, it is necessary to stay on both sides of the joint for a short time to allow sufficient penetration at the edge of the weld to prevent undercut.

The characteristics of this method are that the metal melts well, has a long holding time, the gas is easy to precipitate, and the slag is also easy to float to the surface of the weld, and the quality of the weld is higher, but the residual temperature of the welded weld is higher. The scope of application of this method is basically the same as that of the zigzag method.

5. Triangle transport method. When welding with this transport method, the end of the electrode moves in a continuous triangle and constantly moves forward. According to the different swing forms, it can be divided into two kinds of oblique triangle and regular triangle, and the oblique triangle transport strip method is suitable for the T-joint weld and the horizontal weld with groove in the position of flat welding and upward welding, and its advantage is that it can control the molten metal by the swing of the welding rod, and promote the weld to form well.

The regular triangle strip method is only suitable for the vertical welding of the butt joint and the T-joint weld of the bevel opening, and the characteristics are that it can weld a thick weld section at one time, and the weld is not easy to produce defects such as slag inclusion, which is conducive to improving production efficiency.

6. Circle-shaped transport method. When welding with this method of transporting bars, the end of the electrode continuously moves in a positive circle or oblique circle, and constantly moves forward. The positive circle transport strip method is suitable for welding flat welds of thicker weldments, and its advantages are that the molten pool exists for a long time and the metal temperature of the molten pool is high, which is conducive to the precipitation of oxygen, nitrogen and other gases dissolved in the molten pool, and is convenient for the slag to float.

Hello Welding is when a substance is pressurized and heated to make two objects bonded together! Manual arc welding, argon arc welding, electroslag pressure welding, flash butt welding, oxyacetylene flame welding and cutting, and carbon dioxide shielded welding.

The connection is called welding. There are two categories: electric welding and oxygen welding.

1.Electrode arc welding.

Electrode arc welding is a process method that uses the stable burning arc established between the electrode and the workpiece to melt the electrode and the workpiece, so as to obtain a firm welded joint. During the welding process, the coating is continuously decomposed and melted to form gas and slag, which protects the end of the electrode, the arc, the molten pool and its nearby areas, and prevents harmful pollution of the molten metal by the atmosphere. The electrode core is also continuously melted under the action of arc heat and enters the molten pool, forming the filler metal of the weld.

2.Submerged arc welding.

Submerged arc welding (including submerged arc surfacing and electroslag surfacing welding, etc.) is a method in which the arc is burned under the flux layer for welding. Its inherent welding quality is stable, welding productivity is high, no arc light and little smoke and dust, etc., making it the main welding method in the production of important steel structures such as pressure vessels, pipe sections, and box-shaped beams and columns.

3.TIG welding.

TIG welding is a welding technology that uses argon as a shielding gas. It is also known as argon gas shielded welding. It is to pass argon shielding gas around the arc welding to isolate the air from the welding area and prevent oxidation in the welding area.

Argon arc welding technology is based on the principle of ordinary arc welding, the use of argon to protect the metal welding consumables, through high current to make the welding consumables melt into a liquid state on the welded substrate to form a molten pool, so that the welded metal and the welding consumables to achieve metallurgical combination of a welding technology, because of the continuous delivery of argon in the high temperature melt welding, so that the welding consumables can not contact with the oxygen in the air, thereby preventing the oxidation of the welding consumables, so that stainless steel, iron hardware metals can be welded.

4.Gas welding. <>

Gas welding, English: oxygen fuel gas welding (abbreviated as OFW). It is a welding method that uses the flame generated by the mixed combustion of combustible gas and combustible gas as the heat source to melt the weldment and welding material to achieve interatomic bonding.

The combustible gas is mainly oxygen, and the combustible gas is mainly acetylene, liquefied petroleum gas, etc.

5.Laser welding.

Laser welding is a method of welding using a focused laser beam as an energy source to bombard the heat generated by the weldment. Due to the optical properties of laser such as refraction and focusing, laser welding is very suitable for the welding of micro parts and parts with poor accessibility. Laser welding also has the characteristics of low heat input, small welding deformation, and is not affected by electromagnetic fields.

Due to the high cost of lasers and low electro-optical conversion efficiency, laser welding has not been widely used.

6.Second, welding.

The second shielded welding (full name carbon dioxide gas shielded welding) process is suitable for low-carbon steel and low-alloy high-strength steel various large-scale steel structure engineering welding, its welding productivity is high, the crack resistance is good, the welding deformation is small, the deformation range is large, and the welding of thin plates and medium and heavy plates can be carried out.

Welding methods include: manual arc welding, carbon dioxide gas shielded welding, submerged arc welding, plasma arc welding, sub-arc welding, gas welding, etc.

1.Straight line shipping method. 2.Straight-line reciprocating method. 3.Zigzag strip method. 4.Crescent-shaped transport strip method.

1. What are the categories of welding methods?

2. How many kinds of welding?

3. What are the types of welding methods? What are the characteristics of each?

4. What are the types of welding methods divided into?

1.According to the energy and process characteristics used, welding is divided into three categories: fusion welding, pressure welding and brazing, and each type is divided into various different welding methods.

2.Fusion welding is divided into arc welding, gas welding, thermite welding, electroslag welding, electron beam welding, and laser welding.

3.Pressure welding is divided into resistance spot seam welding, resistance butt welding, ultrasonic welding, ** welding, diffusion welding, friction welding, and high-frequency welding.

4.Brazing includes flame brazing, induction brazing, furnace brazing, salt-solution brazing, electron beam brazing.

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