Structural Steel Fabrication Quality Control and NDT Methods

Heavy industrial buildings, EOT crane gantries, and high-bay warehouses require high structural integrity. A single weld failure can lead to progressive collapse. Deepika Builtech implements strict quality control protocols at our workshops, utilizing Non-Destructive Testing (NDT) to verify weld quality. We specialize in high-strength structural steel structure fabrication in Chennai. 1. Welding Standards and Welder Qualification All welding works are performed in compliance with IS 816 and AWS D1.1 structural welding codes. Our fabricators undergo regular qualifications and certifications to weld high-tensile Grade 345 MPa steel. We utilize MIG/MAG and submerged arc welding (SAW) processes. For heavy industrial fabrications in Thiruvallur and Sriperumbudur, standard NDT testing (UT/MPI) takes 3 to 5 days, costing approximately ₹15,000 to ₹35,000 depending on weld volumes, ensuring full compliance with AWS D1.1 structural welding requirements. 2. Non-Destructive Testing (NDT) Methods To inspect the internal structure of welds, we utilize three main NDT methods: - Dye Penetrant Testing (DPT): A liquid dye is applied to the weld surface to reveal surface-breaking cracks and porosity. It is ideal for checking connection plates and stiffener welds. - Magnetic Particle Inspection (MPI): Used to detect surface and near-surface discontinuities in ferromagnetic materials. It uses a magnetic field and iron powder to reveal defects. - Ultrasonic Testing (UT): High-frequency sound waves are sent into the weld to detect internal flaws, slag inclusions, or incomplete penetration. This is mandatory for full-penetration butt joints on primary columns and rafters of pre-engineered metal buildings. 3. Dimensions and Tolerance Auditing We audit component dimensions using calibrated digital tools to maintain tolerances within IS 7215 standards, ensuring fitment during on-site erection.