Prevention of corrosion of metals under continuous exposure to sodium or calcium chloride refrigerating brine is one of the earliest commercial applications of a chemical inhibitor. Yet comparatively little has been published about the effectiveness of inhibitors under conditions of discontinuous exposure.
An experimental technique designed only to provide comparative data and indicate orders of magnitude rather than precisely determined corrosion rates is used. Experiments establish that chromate effectively minimizes brine corrosion of mild steel and selected aluminum and magnesium alloys intermittently exposed to brines at ordinary temperatures. The importance of ratio between metal surface area and test solution volume is brought out, as is also the effect of pH through comparison of chromate with bichromate. Roughly quantitative indications of inhibitor consumption are reported.
