Investigation of Sever Corrosion of Aluminum parts in Stored Diesel Engine Cooling Systems

摘要

Through the simulation of different parameters that might be responsible for the strong corrosion on the experimental cooling systems, three major failure factors were determined: Depletion of inhibitor additives because of the chemical reaction between inhibitors and ions present in tap water (i.e., Ca+2, Mg+2), leading to formation of insoluble salts. Initiation of pitting corrosion by Cl~ ions introduced into the coolant through tap water as diluant. MIC by the proliferation of corrosion-inducing microorganisms caused by three factors: a) the dilution of the original coolant with tap water containing local bacteria and contamination, b) the reduction in inhibitory compounds through dilution, and c) the successful utilization of EG or inhibitors (at lower concentrations) by introduced bacterial population. 4) Higher coolant concentrations(>20 percent) are less favorable for the development of corrosion-inducing microorganisms and, consequently, to MIC development, and they can be used as a threshold to prevent corrosion damage in such systems.