In the field of sheet metal processing, welding is a vital connection process. However, in the face of a variety of welding processes, how to choose has become the key to ensure the quality and performance of sheet metal products.
Common sheet metal welding processes
1. Manual arc welding
This is a more traditional welding process. It uses the arc heat generated between the electrode and the weldment to melt the metal of the electrode and the weldment to form a weld. Manual arc welding equipment is simple and flexible to operate, suitable for welding in various positions. However, its welding speed is relatively slow, the quality of the weld is greatly affected by the skill level of the welder, and the deformation after welding may be large.
2. Gas shielded welding
Gas shielded welding is divided into carbon dioxide gas shielded welding and argon arc welding.
Carbon dioxide gas shielded welding uses carbon dioxide gas as a shielding gas to prevent oxygen in the air from having adverse effects on the welding pool. This welding process has low cost and high welding efficiency, and is suitable for welding sheet metal parts made of carbon steel and other materials. However, there is more spatter during the welding process, and the welding quality depends to a certain extent on the control of factors such as gas flow and welding wire.
Argon arc welding uses argon as a shielding gas. Argon is an inert gas that can better protect the welding area. TIG welding is suitable for welding sheet metal materials such as stainless steel and aluminum that require high weld quality. It can produce high-quality welds with smooth and beautiful appearance and small welding deformation, but the cost of TIG welding equipment is relatively high, and the welding speed is slower than that of CO2 gas shielded welding.
3. Resistance welding
Resistance welding is a method of welding using the resistance heat generated by the current passing through the weldment and its contact point. Common resistance welding methods include spot welding, seam welding, and butt welding. Spot welding is mainly used for connecting thin plates. It applies pressure and current to the weldment on the contact surface through the spot welding electrode, so that the contact point melts instantly to form a weld. The advantages of resistance welding are fast welding speed, small deformation, and no need for filler materials. However, it has high requirements for the surface cleanliness of the weldment, and the equipment cost is relatively high, which is suitable for mass production.
Considerations for selecting sheet metal welding process
1. Sheet metal material
Different welding processes are suitable for different materials. As mentioned earlier, TIG welding is more suitable for materials such as stainless steel and aluminum, CO2 gas shielded welding is mostly used for carbon steel, and resistance welding performs well in thin plate welding. If the sheet metal material is a combination of multiple materials, the compatibility of different welding processes also needs to be considered.
2. Welding thickness
For thicker sheet metal parts, manual arc welding may be more suitable because it can provide sufficient penetration. For thin plates (less than 3mm thick), resistance welding or argon arc welding can better control welding heat and reduce deformation.
3. Welding quality requirements
If the weld quality requirements are extremely high, such as sheet metal products in aerospace,
Medical Equipment and other fields, argon arc welding is a better choice. It can provide high-quality and beautiful welds. For some ordinary industrial sheet metal parts that do not require particularly high appearance and internal quality, carbon dioxide gas shielded welding or resistance welding may meet the requirements.
4. Production batch
For sheet metal parts produced in large quantities, the high speed and stability of resistance welding make it the first choice. Manual arc welding is more suitable for small batch, single piece production or maintenance operations due to its low efficiency.
5. Cost factors
Costs include equipment costs, welding material costs, labor costs, etc. The equipment and material costs of carbon dioxide gas shielded welding are relatively low, the equipment cost of argon arc welding is high, and the labor cost of manual arc welding may be high (depending on the proficiency of the welder). Under the premise of meeting the welding requirements, the welding process with lower cost should be selected as much as possible.
In short, when choosing the sheet metal welding process, it is necessary to comprehensively consider various factors such as sheet metal materials, weldment thickness, welding quality requirements, production batch and cost, so as to ensure that the welding process matches the needs of sheet metal products, so as to obtain high-quality and high-efficiency sheet metal welding products.
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