Use of Ion Microanalyzer in the Analysis of Passive Layers on Stainless Steel

Abstract

Passive layers on various stainless steels were studied with an ion microanalyzer. An argon ion beam was directed on the specimen surface in an oxygen atmosphere. The use of oxygen atmosphere effectively minimized the difference in ion yields of the elements in the oxidized layers and matrices, making it possible to determine these elements with good reproducibility. 18% Cr–8% Ni and 18% Cr–8% Ni–0.4% Ti stainless steel was exposed to neutral water containing 8 ppm oxygen at 289 °C. The passive layers contained larger amounts of iron and smaller amounts of chromium than the matrices.

Ferrous metallurgy

“…A calorimetric method for this determination in high-allov steels (275) has excellent sensitivity and better precision than potentiometric titration or atomic absorption. Several other techniques have been applied in making this determination in steels, such as X-ray photoelectron spectroscopy (19,391), electron microprobe (397), secondary ion mass spectrometry (284), ion microprobe (80,358,359), and electron energy loss spectrometry (285).…”

“…Ion microanalyzers and X-ray photoelectron spectrometers have been used to determine iron in high-temperature alloys (359), and decorative films and passive oxide layers on stainless steel (19,358). LANTHANIDES Spectrophotometry.…”