IIW IWI-B case studies
IIW IWI-B · Put your knowledge to work in context.
The International Welding Inspector - Basic (IWI-B) is the entry level of the IIW's three-tier welding inspection qualification, sitting below IWI-S and IWI-C. It is aimed at people who check welded fabrication against drawings, welding procedure specifications and applicable standards: welding coordinators, workshop supervisors, quality control staff, and technicians moving from fabrication into inspection. The IIW IWI-B case studies are 5 cases and about 4,072 words.
1Clustered porosity after a submerged-arc flux change on a 25 mm shell seam
A fabricator is welding the longitudinal seam of a 25 mm S355J2+N shell, double-V, multi-pass submerged-arc welding on a column-and-boom tractor. The qualified WPS uses 4.0 mm wire, DC+, 620 A, 28 V, 340 mm/min, and flux to ISO 14174, classification SA FB 1 55 AC H5.
833 words, about 4 min2Delayed toe cracking in the HAZ of a thick S460ML node after an un-preheated repair
A 45 mm thick S460ML tubular node is welded with a basic flux-cored wire under M21 shielding gas, with 150 °C preheat and 250 °C maximum interpass temperature recorded on the WPS. An MPI indication in the root region of one brace was gouged out and re-welded the next morning at 12 °C ambient, without preheat, and the operator did not record interpass temperature because "it was only a small repair".
799 words, about 4 min3A fabricator proposes a larger fillet to cure a fatigue problem at a stiffener end
A runway girder for an overhead crane has a transverse stiffener welded to a 12 mm web with a 6 mm fillet on both sides, terminating 50 mm above the tension flange. The contract is EN 1090-2, execution class EXC3, and the fatigue verification to EN 1993-1-9 uses a detail category appropriate to a welded stiffener end, with a stress range of 65 MPa at 2 × 10^6 cycles.
731 words, about 4 min4Level B visual acceptance on a 10 mm butt weld: undercut, cap height and missing identification
A 10 mm S355 plate butt weld, single-V, GMAW, is made in a workshop. The drawing note reads: "all welds 100% visual, acceptance ISO 5817 level B".
843 words, about 4 min5EXC3 contract in a shop certified to ISO 3834-3 with 8 mm welder qualifications
A workshop holds ISO 3834-3 certification and has for years produced EN 1090-2 EXC2 members. It wins a contract for EXC3 members in S355J2+N, 20 mm thick, where the specification requires Charpy 27 J at 0 °C.
866 words, about 4 min