Arc welding refers to using the arc as a heat source and using the physical phenomenon of air discharge to convert electrical energy into thermal energy and mechanical energy required for welding, so as to achieve the purpose of connecting metals. The main methods are electrode arc welding, submerged arc welding, gas shielded welding, etc. It is the most widely used and most important fusion welding method, accounting for more than 60% of the total welding production.
Electrode arc welding is the most widely used welding method in industrial production. Its principle is to use the heat generated by arc discharge (commonly known as arc combustion) to melt the electrode and the workpiece and form a weld after condensation, so as to obtain a solid joint welding. process.
Electrode arc welding is a welding work performed by manually manipulating the electrode, which can perform multi-position welding such as flat welding, vertical welding, horizontal welding and overhead welding. Other
In addition, because the electrode arc welding equipment is lightweight and flexible in handling, it can be said that the electrode arc welding can perform welding operations in any place with a power supply. It is suitable for welding of various metal materials, various thicknesses and various structural shapes.
Safety features of electrode arc welding: The no-load voltage of electrode arc welding equipment is generally 50V-90V, while the safe voltage that the human body can withstand is 30V-45V. It can be seen that manual arc welding equipment will cause life to people. Dangerous, when welding, you must wear protective equipment.
The most important parameters in the welding specification of arc welding are:
The type of electrode (depending on the material of the base metal), the diameter of the electrode (depending on the thickness of the weldment, the position of the welding seam, the number of welding layers, the welding speed, the welding current, etc.), the welding current, the number of welding layers, the welding speed, etc.
In addition to the above-mentioned ordinary arc welding, in order to further improve the welding quality, we also use:
Gas shielded arc welding: such as argon arc welding using argon as the shielding gas in the welding area, carbon dioxide shielded welding using carbon dioxide as the shielding gas in the welding area, etc. Continuously spraying shielding gas in the middle of the welding area isolates the air from the molten metal in the welding area, so as to protect the arc and the liquid metal in the welding pool from pollution by oxygen, nitrogen, hydrogen, etc. in the atmosphere, so as to improve the welding quality. .
Tungsten argon arc welding: Arc welding with a high melting point metal tungsten rod as an electrode for generating an arc during welding and under the protection of argon gas.
Plasma arc welding: This is a welding method developed from tungsten argon arc welding.
Judgment of arc welding current:
Small current: narrow weld bead, shallow penetration, easy to form too high, lack of fusion, incomplete penetration, slag inclusion, porosity, welding rod adhesion, arc breaking, no arc ignition, etc.
Large current: wide bead, large penetration, undercut, burn-through, shrinkage, large spatter, over-burning, large deformation, weld bead, etc.
