Abstract
Corrosion in boiler systems can be conveniently monitored by electrochemical corrosion rate measurements or by measuring the concentrations of corrosion products in the water streams. Electrochemical probes can measure corrosion rates directly in feedwater or condensate. When steps are taken to reduce the apparent solution resistance simple dc polarization techniques yield accurate measurements of corrosion rate in real time. Because of the low oxygen conditions that prevail in boiler systems active corrosion can be detected throughout the system by colorimetric determination of ferrous iron. Ferrous iron measurements are particularly useful for detecting corrosion in feedwater systems but they are equally useful for detecting corrosion inside boilers when accurate information on cycles of concentration is available. The release and movement of iron oxides from steel surfaces can be tracked with particle monitoring. Particle monitoring is especially useful for detecting corrosion product release events in the condensate systems so that steps can be taken to prevent iron oxide particles from being returned to the boiler.
