A Simple Coupon Test for Analyzing Corrosion Caused by Combustion Products of Liquid Fuels

A liquid, while burning on a cold surface, can dissolve significant amounts of its combusion products. After reaction with a suitable solid surface, these products are identifiable by infrared spectroscopy. Corrosion derived in this manner can be quantified gravimetrically. Thus, steel corrosion from methanol combustion was measured by burning several layers of the alcohol on a steel coupon, while recording the coupon weight. Corrosion enhancement by fuel contaminants, such as sulfur or peroxide, was measured by this method, as well as, corrosion inhibition by cofuels and lubricant layers. The flaming coupon test is also suitable for comparing corrosion resistance of metals as a function of alloy composition, or for ranking protective coatings. Some of the corrosion fundamentals involved in the rust formation during this test are analyzed. The additional data presented here advance earlier conclusions that corrosion caused by burnt automotive fuels, fuel additives, and contaminants can be simulated in the laboratory by this method.