Welding and metallurgy expertise
Advice on materials and their weldability, expertise on weld defects and their acceptance criteria.
Materials and weldability
The choice of a material governs how it can be welded and how the joint behaves. We advise you on the weldability of materials and on the effects of welding on their properties.
We help you choose the material, the process and the filler metal, and anticipate the effects of welding: heat-affected zone, distortion, residual stresses, cracking risks.
Weld defects
Cracks, porosity, lack of fusion: we assess weld defects against the acceptance criteria, in particular those of ISO 5817, which defines quality levels for fusion-welded joints.
- hot and cold cracks;
- porosity and gas pores;
- lack of fusion and incomplete penetration;
- inclusions, undercuts and shape imperfections.
ISO 6520-1 classifies these imperfections, and ISO 5817 sets the limits of quality levels B, C and D for each of them.
Expertise after an incident
When a weld fails or a batch is rejected, we analyse the defect, look for its causes and propose corrective actions, whatever your sector: rail, nuclear, oil and gas, chemicals, shipbuilding, wind energy, aerospace, defence, pressure equipment, steel construction.
Frequently asked questions
What is the difference between quality levels B, C and D?
ISO 5817 defines three quality levels for imperfections in fusion welds: B (stringent), C (intermediate) and D (moderate). The required level depends on the application; it is given in the specification or the product standard.