Electrochemical Testing

All corrosion is an electrochemical process of oxidation and reduction reactions.  Therefore, controlled electrochemical experimental methods can be used to characterize the corrosion properties of metals and metal components in combination with various electrolyte solutions or soil environments. The corrosion characteristics are unique to each metal/solution system. Matergenics performs electrochemical test procedures to determine or predict the corrosion rates of metals in a wide range of environments. Among the electrochemical techniques  are the ASTM / NACE techniques, Cyclic Polarization, Impedance Spectroscopy,  linear polarization tests , electrochemical tests for hydrogen permeation, real-time corrosion predictions for materials, and others. Environments include corrosive solutions, soil environments and atmospheric corrosion monitoring. The following plot exhibits a case example for using electrochemical technique (ASTM G61All corrosion is an electrochemical process of oxidation and reduction reactions. As corrosion occurs, electrons are released by the metal (oxidation) and gained by elements (reduction) in the corroding solution. Because there is a flow of electrons (current) in the corrosion reaction, it can be measured and controlled electronically. Therefore, controlled electrochemical experimental methods can be used to characterize the corrosion properties of metals and metal components in combination with various electrolyte solutions. The corrosion characteristics are unique to each metal/solution system.) for selection of  materials in acidic chlorides. The plot clearly indicates Type 304 stainless steel is not a proper material selection for acidic chloride environments

ASTM G61- Materials Selection in Corrosive Environments. Standard Test Method for Conducting Cyclic Potentio-dynamic Polarization Measurements for Localized Corrosion Susceptibility of Iron-, Nickel-, or Cobalt-Based Alloys

Electrochemical Corrosion Cells

The above photos show various  “Electrochemical Corrosion Cells” at our electrochemical laboratory  to test corrosion of bare or painted test coupons

Impedance Measurements on Organic Coatings on Mild Steel in Sodium Chloride Solutions Impedance Spectroscopy provides very useful information about protective coatings. The above plots clearly exhibits how good the coating is!