Environmental problems in the coil-coating industry have caused a trend towards non-polluting pretreatment/primer combinations. In this work some environmentally-friendly systems have been studied. Impedance spectroscopy on deformed (T-bent) and damaged samples has been used as a tool to obtain a selective evaluation of the best systems. Nitro-cobalt chemical conversion, with fluo-zirconate passivation coated by an epoxy-polyurethane primer having ionic exchange active pigments, gave the best solution for the systems studied.