Volatile Products in the Corrosion of Cr, Mo, Ti, and Four Superalloys Exposed to O 2 Containing H 2 O and Gaseous NaCl

Abstract

Cooled target collection techniques were used to study the formation of volatile products when samples of Cr, Ti, IN‐738, 713C, NASA‐TRW VIA, and B‐1900 were exposed at elevated temperatures to oxidizing environments containing and . Samples were heated to 1050°C in 1 atm of slowly flowing oxygen, saturated with water at 21°C, and containing about 50 ppm . Volatile products were detected for all materials except B‐1900 and Ti. High pressure mass spectrometric sampling was used to directly identify volatile products emanating from samples of Cr and IN‐738 subject to the above environments. Mo samples were also studied at 675°C with 4 ppm added to the environment. For Cr and IN‐738 the volatile species were identified primarily as , ,, and . These same species are deduced to prevail for 713C and NASA‐TRW VIA. For Mo, the major species identified were, , , and .