1988 Volume 37 Issue 10 Pages 608-613
Several case histories of corrosion failure of turbo compressor impellers are presented and the corrosion conditions, materials experiences, a principal cause of the impeller failure and possible ways to prevent the failure are discussed. The corrosion conditions in the turbo compressor are varied from mild to severe depending on combination of the operating atmosphere and the selection of materials for construction. The deposition of basic copper sulphate, antlerite formed by the reaction of SO2 contaminated air and the copper alloy heat exchanger tube, on the impeller surface results in a strongly oxidative and acidic corrosion environment for the impeller. Then a low alloyed high strength steel impeller suffers severe corrosion attack, while 13Cr martensitic stainless steel is subjected to stress corrosion cracking via active path corrosion. Possible ways to prevent the corrosion failure are change of the heat exchanger tube material and introduction of a mist separator to reduce and avoid the formation of antlerite. Further, full desensitization of stainless steel impeller and the use of 17-4PH stainless steel are very effective.
