The method of inspection of welds in structural steel should be according to IS: 822 and extent of inspection and testing shall be in accordance with the relevant applicable standard.
The inspection of welds during all stages of fabrication and erection should be done for the following objectives.:
i) To check the conformity with the relevant standards and suitability of various welding equipments and their performance.
ii) To witness/approve the welding procedure qualification.
iii) To witness/approve the welders performance qualification.
iv) To check whether shop/field welding being executed is in conformity with the relevant specifications and codes of practice.
Following are the methods of inspection of welds for structural steel:
Visual Inspection of welds:
All finished welds (i.e. 100 percent) shall be visually inspected for identification of the following types of weld defects & faults.
- Weld defects occurring at the surface such as blow holes, exposed porosity, unfused welds etc.
- Surface cracks in the weld metal or in the parent metal adjacent to it.
- Damages to the parent metal such as undercuts, burning, overheating etc.
- Profile defects such as excessive convexity or concavity, overlapping, unequal leg lengths, excessive reinforcement, incompletely filled grooves, excessive penetration beads, root grooves etc.
- Distortion due to welding i.e., local shrinkage, camber, bowing, twisting, rotation, wariness etc.
- Linear eccentric, angular and rotational misalignment of parts.
- Dimensional errors.
Mechanical Tests on welds:
The mechanical testing (such as tensile load tests,bend tests, impact tests etc.) shall be done in accordance with the relevant standards.
Magnetic Particle / Dye Penetration / Ultrasonic Examination:
The examination shall be done on joints randomly selected. The tests shall be carried out by employing approved testing procedure in accordance with IS: 822.
Radiographic Examination on welds:
Radiographic examination is carried out only in special cases on random joints. The tests is carried out as per procedure in accordance with IS: 822.