摘要: |
The corrosion rates of steel exposed to salt solutions inhibited with several phosphate or phosphonate salts together with salts of magnesium, calcium, or zinc were measured to determine their effectiveness as low-corrosion deicers. At levels present in commercially available deicers, ortho- and polyphosphates mixed with magnesium or zinc salts provided strong inhibition of chloride corrosion. Linear polarization resistance (LPR) was used to monitor the corrosion rate of an orthophosphate-inhibited deicer over time, showing that the corrosion rate remained very stable and low in the presence of the inhibited deicer. The overall decreases in the corrosion rate of the inhibited salt relative to those of plain salt determined by LPR and weight loss were 89% and 81%, respectively, indicating good agreement between the two methods. Electron microscopy and energy dispersive spectroscopy were used to analyze steel surfaces exposed to different deicer formulas. Surface studies indicate that the inhibitors become incorporated into the surface of the steel, causing the formation of a compact, uniform layer that may reduce the corrosion by forming a barrier between the metal and the corrosive environment. |