Magetic Particle Inspection testing - Non relevant Indications

In Magnetic Particle testing it is common to misinterpret Non-relevant indications while evaluating the indication after testing. However such indications needs careful analysis by the NDT inspector to judge the actual cause of such indications. We here by present a series of photographs from a martensitic stainless steel casted turbine blade that has been weld repaired and offered for Magnetic particle testing produced Non relevant Indications on the examination surfaces attributed to the change in permeability of weld and parent materials but nor due to an actual defect.

Even through they looks very close to relevant indications, careful observation and analysis of such magnetic particle indications confirmed that they are non relevant by the expert NDT inspectors.