Industrial Exposures of Metals to Acids

Metals are exposed to the action of acids in many different ways and for many different reasons. The exposures can be severe, but in many cases, the corrosion can and should be controlled by means of inhibitors. Processes in which acids play a very important part are  

reported by NACE, show that at 74 °C, concentrations of inhibitor at 0.03% reduced corrosion rates in 5, 10, and 20% acid from 0.1 to a little more than 0.001 mg/cm /day, rates at all three concentrations clustered about the same point. At 95 °C, under the same conditions, results were more scattered, the rate for 10% acid being reduced from 0.1 mg/cm /day for the uninhibited control to a little less than 0.01 mg/cm /day in 5% acid with slightly increased corrosion rates for the 10 to 20% concentrations. Rates of all three at 95 °C were less than 0.01% for 0.03% inhibitor concentration. 

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