Monitoring active corrosion of metals in natural environments with magnetometry

Abstract Magnetic fields induced by electrochemical activity from aqueous corrosion of two metals are monitored remotely with low cost sensors in a natural (unshielded and non-cryogenic) laboratory environment. Passive magnetic field measurement is carried out with economical and practical sensors. The measured magnetic fields are ascribed to active uniform aqueous corrosion processes in both aluminum and steel, and we demonstrate a direct relation between corrosion rate and magnetic activity for each case. The results indicate that magnetic activity owing to uniformly corroding surface is not magnetically silent in this particular testing configuration, and the rate of corrosion can be monitored in a practical manner.