Effectiveness of Ferrous Sulfate as an Inhibitor for Sulfide-Induced Corrosion of Copper-Nickel Alloys.

摘要

A program is described which investigates accelerated corrosion of ship piping systems during and after outfitting in polluted brackish harbor waters. As part of this program,various ferrous sulfate inhibitor treatments were evaluated in laboratory exposures of 90-10and 70-30copper-nickel specimens to seawater and seawater containing 0.2parts per million sulfide. Weight loss,maximum thickness loss,and instantaneous corrosion rate data were obtained. Neither pretreatment by the inhibitor before sulfide exposure,nor intermittent inhibitor treatment during sulfide exposure significantly reduced the sulfide-induced attack on either alloy. Treatment after sulfide exposure did not reduce the sulfide-induced attack on 90-10copper-nickel and only partially reduced the attack on 70-30copper-nickel. Continuous treatment completely eliminated the attack on both alloys,probably because the inhibitor stripped the harmful sulfides from solution. Results of these exposures should not be generalized to predict the action of the inhibitor against lower sulfide concentrations which have been measured in harbor waters. (Author)