DEFINING THE CORROSION PERFORMANCE WINDOW FOR GRADE 28 TITANIUM

摘要

An extensive corrosion performance database for wrought and welded Grade 28 titanium based on laboratory testing has been compiled. General corrosion testing in hot dilute reducing acids and crevice testing in high temperature acidic chloride and sulfate-rich brines reveal that Grade 28 titanium is substantially more resistant than the titanium Grades 2, 9, and 12, and nearly approaches that of Grades 7 and 26 in many environments. Furthermore, despite its higher strength and alloying content, this alloy is shown to resist pitting and stress corrosion in hot acidic aqueous media. Alloy crevice corrosion resistance may be limited in situations where severe crevices exist in hot acidic chloride-rich brines and strong oxidizing species are present. These corrosion performance enhancements derived from a minor ruthenium alloy addition make the higher strength Grade 28 titanium alloy attractive for high temperature/pressure CPI equipment handling corrosive brines, salt solutions, organic acids, and reducing acid media containing oxidizing species.