Welding rods and wires

Application of welding rods and welding wires

Welding rods and welding wires are commonly used welding materials in metal processing equipment. They play a vital role in the production and manufacturing of various industries. The following will introduce the application of welding rods and welding wires in detail from the aspects of material type, application and characteristics.

◆  Material types of welding rods and welding wires

The materials of welding rods and welding wires can be divided into various metals and non-metallic materials. Common metal rods and welding wires include copper, aluminum, zinc, galvanized steel, stainless steel, etc. Non-metallic welding rods and welding wires include graphite, coatings, sealants, etc. Welding rods and welding wires of different materials can meet the needs of different industries.

◆  Application of welding rods and welding wires

(1) Manufacturing industry: welding rods and welding wires are widely used in manufacturing industries, such as automobile manufacturing, shipbuilding, steel structure manufacturing, etc. Welding rods and welding wires are used to connect metal components, improve the strength and stability of the structure, and ensure product quality;

(2) Construction engineering: The application of welding rods and welding wires in the field of construction engineering mainly includes welding steel structures, welding steel bars and welding aluminum materials. Welding wire can improve the connectivity and strength of materials in construction projects, ensuring the safety and stability of projects

(3) Power industry: Welding wire is widely used in the power industry. For example, welding wire is used to connect and repair wires and cables to ensure the stability and normal operation of power transmission

(4) Chemical industry: Welding wire is mainly used in the chemical industry to weld pressure vessels, pipelines and petrochemical equipment. The use of welding wire can improve the sealing and safety of equipment and prevent leakage and accidents

(5) Aerospace: The application of welding wire in the aerospace field mainly includes aircraft manufacturing, turbine machinery welding and spacecraft structure welding. The use of welding wire can improve the quality and performance of aerospace devices and ensure safe flight

(6) Electronic and electrical industry: Welding wire is mainly used in the electronic and electrical industry to connect circuit boards and components, improving the conductivity and stability of electronic devices

(7) Military industry: Welding wire is widely used in the military industry, such as the manufacture and repair of weapons and equipment such as tanks, aircraft, and missiles. The use of welding wire can improve the corrosion resistance and earthquake resistance of weapons and equipment and ensure the smooth progress of military operations.

◆  Characteristics of welding rods and wires

(1) Reliable welding quality: welding rods and wires can ensure reliable quality of welding joints, beautiful welds, and good mechanical properties and corrosion resistance

(2) Easy operation: welding rods and wires are easy to operate and suitable for various welding environments, whether it is a factory production line or outdoor construction;

(3) Strong adaptability: welding rods and wires are suitable for welding various metal materials and non-metallic materials, and can meet the needs of different industries;

(4) Economic and energy-saving: welding rods and wires have low cost of use, can be recycled, and save resources

(5) Environmentally friendly: welding rods and wires do not produce harmful substances and waste gas, and do not pollute the environment In general, welding rods and wires have important uses in all walks of life. Their functions include welding metal components to connect wires and cables, welding building structures, welding pressure vessels, and repairing weapons and equipment. Welding rods and wires have the advantages of easy operation, high welding quality, strong adaptability, economic energy saving and environmental friendliness, and are indispensable welding materials in modern industry.

Welding types

◆  Arc welding

Principle - arc welding method using manually operated electrodes for welding. The stable burning arc established between the electrode and the weldment is used to melt the electrode and the weldment, thereby obtaining a firm welded joint. It is gas-slag combined protection.

Main features - flexible operation; low assembly requirements for the welded joint; wide range of weldable metal materials; low welding productivity; strong dependence on weld quality (depending on the welder's operating skills and on-site performance).

Application - widely used in manufacturing and maintenance industries such as shipbuilding, boilers and pressure vessels, machinery manufacturing, building structures, and chemical equipment. Applicable to welding of various metal materials, various thicknesses, and various structural shapes (in the above industries).

◆  Submerged arc welding (automatic welding)

Principle - the arc burns under the flux layer. The heat generated by the burning arc between the welding wire and the weldment is used to melt the welding wire, flux, and parent material (weldment) to form a weld. It is slag protection.

Main features: high welding productivity; good weld quality; low welding cost; good working conditions; difficult to weld in space; high requirements for weldment assembly quality; not suitable for welding thin plates (arc stability is poor when welding current is less than 100A) and short welds.

Application: widely used in shipbuilding, boilers, bridges, lifting machinery and metallurgical machinery manufacturing. Submerged arc welding can be used for welds that can be kept in a horizontal position or with a small inclination angle. The plate thickness must be greater than 5 mm (to prevent burn-through). Welding carbon structural steel, low alloy structural steel, stainless steel, heat-resistant steel, composite steel, etc.

◆  Carbon dioxide gas shielded welding (automatic or semi-automatic welding)

Principle: A consumable arc welding method using carbon dioxide as a shielding gas. Gas protection.

Main features: high welding productivity; low welding cost; small welding deformation (arc heating is concentrated); high welding quality; simple operation; large spatter rate; difficult to weld with AC power supply; poor wind resistance; cannot weld easily oxidized non-ferrous metals.

Application: mainly weld low carbon steel and low alloy steel. Suitable for various thicknesses. Widely used in automobile manufacturing, locomotive and vehicle manufacturing, chemical machinery, agricultural machinery, mining machinery and other departments.

◆  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.

Shielding gas is usually argon or helium or their mixture. MIG uses inert gas, and MAG adds a small amount of active gas, such as oxygen, carbon dioxide, etc., to the inert gas.

Main features-good welding quality; high welding productivity; no deoxidation and dehydrogenation reaction (easy to form welding defects, and the surface cleaning requirements of welding materials are particularly strict); poor wind resistance; complex welding equipment.

Application-almost all metal materials can be welded, mainly used for welding of non-ferrous metals and their alloys, stainless steel and some alloy steels (too expensive). The thinnest thickness is about 1 mm, and the maximum thickness is basically unrestricted.

◆  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 material and the filler wire (filler wire may not be added) to form a welding seam. The electrode does not melt during welding.

Main features: strong adaptability (stable arc, no spatter); low welding productivity (poor current carrying capacity of the tungsten electrode (prevent tungsten electrode melting and evaporation, prevent tungsten from being caught in the weld)); high production cost.

Application: Almost all metal materials can be welded, commonly used for welding stainless steel, high-temperature alloys, aluminum, magnesium, titanium and their alloys, refractory active metals (zirconium, tantalum, molybdenum, niobium, etc.) and heterometallic metals. Welding thickness is generally less than 6 mm, or base welding of thick parts. Using a small angle groove (narrow groove technology), narrow gap TIG automatic welding of a thickness of more than 90 mm can be achieved.

◆  Plasma arc welding

Principle: A method of welding with a high energy density plasma arc by using the restraining effect of a water-cooled nozzle on the arc.

Main features (compared with argon arc welding) - ⑴ Concentrated energy and high temperature can achieve pinhole effect for most metals within a certain thickness range, and can obtain welds with full penetration and uniform reverse surface formation. ⑵ The arc has good stiffness, and the plasma arc is basically cylindrical. The change in arc length has little effect on the heating area and current density on the weldment. Therefore, the change in arc length of plasma arc welding has little effect on weld formation. ⑶ The welding speed is faster than argon arc welding. ⑷ It can weld finer and thinner workpieces. ⑷ The equipment is complex and the cost is high.

Applications

◆  Penetration (small hole) plasma arc welding:

Using the characteristics of small diameter, high temperature, high energy density and strong penetration of plasma arc, under appropriate process parameters (larger welding current 100A~500A), the weldment is completely melted through, and under the action of plasma flow, a small hole penetrating the weldment is formed, and part of the plasma arc is ejected from the back of the weldment. It can be formed on one side and on both sides, and is most suitable for welding 3~8 mm stainless steel, titanium alloy below 12 mm, 2~6 mm low carbon steel or low alloy structural steel, and butt welding of copper, brass, nickel and nickel alloy. (If the plate is too thick, it is difficult to form a small hole due to the limitation of plasma arc energy density; if the plate is too thin, the small hole cannot be completely closed by liquid metal, so the small hole welding method cannot be realized.)

◆  Melting (dissolution) plasma arc welding

Using a smaller welding current (30A~100A) and a lower plasma gas flow, a mixed plasma arc welding method is used. No small hole effect is formed. Mainly used for welding thin plates (less than 0.5 to 2.5 mm), welding of layers after multi-layer welding and welding of fillet welds.

◆  Micro-beam plasma arc

Plasma arc welding with a welding current below 30A. The nozzle diameter is very small (Φ0.5 to Φ1.5 mm), and a needle-shaped plasma arc is obtained. Mainly used for welding ultra-thin, ultra-small, and precise weldments less than 1 mm.