Detection of cracks in stainless metal coating - using reference electrodes esp. used for nuclear cooling circuits

摘要

Process for detecting cracks in a protective metal layer consists of immersing the surface in an electrolyte soln. and using a reference electrode to produce a chart showing local variations of electrochemical potential on the metal surface. The process is esp. for detection of corrosion fatigue cracks in stainless steel surfaces on fenitic steel used e.g. for seamed tubes in water cooled nuclear reactors. The process can either be used to check components before installation, or for checking water-tightness during periods when the plant is closed. Detection is precise and easily carried out.