Welding is one of the most important processes in many technical fields, including construction, manufacturing, energy, transport, machinery, and metal fabrication. A welded joint may look simple from the outside, but its real quality depends on many controlled factors: the material, welding method, heat input, filler metal, welder skill, testing method, and working conditions. This is why welding procedure qualification is so important. ISO 15614 gives a clear framework for
