Skip to Main Content

Abstract

Original carbon steel and subsequent replacement austenitic stainless steel superheater tube U-bend failures occurred in a waste heat boiler. The carbon steel tubes had experienced metal wastage in the form of caustic corrosion gouging, while the stainless steel tubes failed by caustic-induced stress-corrosion cracking. Sodium was detected by EDS in the internal deposits and the base of a gouge in a carbon steel tube and in the internal deposits of the stainless steel tube. The sodium probably formed sodium hydroxide with carryover moisture and caused the gouging, which was further aggravated by the presence of silicon and sulfur (silicates and sulfates). It was recommended that the tubes be replaced with Inconel 600 or 601, as a practical option until the carryover problem could be solved.

You do not currently have access to this chapter.
Don't already have an account? Register

Allen W. Hearn, Harold Rawlinson, G. Mark Tanner, 1993. "Caustic Gouging and Caustic-Induced Stress-Corrosion Cracking of Superheater Tube U-Bends", Handbook of Case Histories in Failure Analysis, Khlefa A. Esaklul

Download citation file:


Close
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal