Creating sturdy and reliable steel structures involves various methods, and one highly favored approach is electric arc welding. This technique utilizes an electric arc to generate heat, melting both the base and filler materials to form a molten weld pool in the joint. Its popularity stems from its cost-effectiveness compared to alternative methods.
Steel structures rely on fastening methods such as welding, riveting, and bolting. While riveting and bolting involve attaching workpieces using rivets and bolts, welding employs the melting of workpieces to fuse them together seamlessly.
To commence the fabrication process, a full-scale figure of the steel structure is drawn on a level platform. This drawing can be done either in its entirety or in parts, based on site conditions or provided drawings. Steel tape is used for precise measurements of the steel members.
In the fabrication phase, shop drawings play a crucial role by providing detailed information on the steel components, including location, type, length, size, and weld details. Prior to actual fabrication, components are prepared, marked, or painted with identification marks as per the shop drawings. The accuracy of the fabrication process is essential to ensure members can be assembled without any undue force, packing, or strain. Additionally, templates are marked on steel members, indicating welding locations. The ends of steel members are marked for cutting to required dimensions, and the steel sections are straightened or flattened to remove twists.
The welding process is central to the construction of steel structures and is exclusively performed using the electric arc method. In cases where electricity is unavailable, gas welding with an oxyacetylene flame is employed. The welding is executed by fully trained and experienced welders, following the details outlined in the shop drawings. Efforts are made to minimize post-erection welding, considering the challenges posed by heights and difficult positions on scaffolding, with an emphasis on both quality and cost-effectiveness.
To adhere to standards, the maximum electrode diameter for welding is in accordance with IS: 814 and appendix “B” of IS: 823. Joint surfaces must be free from loose mill scale, rust, paint, grease, or any foreign matter that could compromise weld quality and workmanship. When welding outdoors, precautions are taken to shield the work area from wind or rain, ensuring optimal welding conditions.