Applying methods of welding steel structures is extremely common in constructing steel structures. Let’s explore the definition of structural steel welding, the common welding methods, and the standards of structural steel welding with Pebsteel in this article below.
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1. What is structural steel welding?
Welding uses heat or an electric arc to melt a small portion of the metal at the contact point, causing the metal to fuse. After cooling, the metal solidifies, forming a weld.
Structural steel welding is a technical process used in the construction and metal manufacturing industries to join steel structural components. The process of welding steel structures is a crucial part of building large industrial facilities such as high-rise buildings, bridges, factories, and other infrastructure projects.
2. Some popular structural steel welding methods
2.1. Manual arc welding
Manual arc welding in steel structures uses an electric current for operation. An electric arc flame appears between the two metal ends to be welded and the welding rod. The metal in the welding rod melts into droplets and falls into the welding groove due to the pulling force of the electric field. Two molten metal parts blend together and, once cooled, form a weld bead. The essence of a weld bead is the connection between the molecules of the melted metals. A weld has the ability to withstand forces equivalent to those of basic steel.
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2.2. Automatic and semi-automatic arc welding
It provides high productivity and ensures the weld’s mechanical integrity. Automatic and semi-automatic arc welding methods in steel structures can also save electrical energy and provide good working conditions for laborers.
In theory, automatic welding is similar to manual welding, except the coated welding rod is replaced with an uncoated wire reel, and an automated machine carries out the welding process. The welding flux is evenly distributed in advance into the welding groove..The electrode wire is automatically fed at a steady rate matching the speed of the welding machine.
Automatic welding has many significant advantages. The deep melting groove provides conditions for a high-quality weld. The molten metal is coated with a thick layer of flux, allowing it to cool gradually, creating conditions for gas bubbles to escape and making the weld stronger. The welding arc burns beneath the flux layer, posing no harm to the health of the welder.
Currently, there is a semi-automatic welding method using a flexible welding wire. Inside the wire tube, there is welding flux. This method is widely used due to its convenience.
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3. Structural steel welding standards
After completion, the weld of the steel structure must pass the following six standard inspections:
3.1. External Inspection:
- The weld must be free from cracks on the surface and molten metal.
- No porosity, undercuts, burn-through, lack of fusion, or other technological defects are allowed.
- There should be no angular breaks or misaligned edges.
- Deviations in size and shape of the weld and protrusions that compromise strength are not acceptable.
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3.2. Visual Inspection:
- There should be no signs of cracks in the molten metal or the heat-affected zones of the base metal.
- No lack of fusion between the layers of the weld and the bevel edge is allowed.
- Cracks or fractures in the structural part are not allowed, as they can reduce the metal’s elasticity and flexibility.
3.3. Hydraulic Inspection:
- The weld should show no signs of cracks.
- There should be no signs of water leakage.
- No significant deformations should be detected.
3.4. Weld Test Results Inspection:
- This value, calculated as the average of results from test samples, should not be at least the minimum strength of the corresponding steel.
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4. Conclusion
Above are the details about the definition and some structural steel welding methods. If customers seek comprehensive solutions for Prefabricated Steel Buildings and Steel Structures, please contact Pebsteel via email at Marketing@pebsteel.com.vn or phone at +84 908 883531 for immediate consultation.
*** This article is intended to provide general information about the pre-engineered steel building and steel structure industry only. For further details or clarification based on your needs, please contact Pebsteel directly.
