Study of oxide protective layers on stainless steel by AES, EDS and XPS

Abstract

A protective oxide layer was formed on the surface of stainless steel by standard industrial-type thermal treatment. Additional post-thermal treatment annealing and polishing followed by annealing were applied in an attempt to improve characteristics of the layers. Oxide layers formed on samples without and with different types of post-thermal treatment processing were analysed and compared. Several techniques were employed. SEM was used to image the surface; AES, XPS and energydispersive spectroscopy (EDS) were all used to probe the elemental composition of the oxide layers. AES was also used as the most straightforward method to obtain depth profiles. Low beam energy EDS was used in an attempt to obtain some fast averaged volume information from the layers. XPS was mainly used for determining chemical states on the surface of the sample but not for depth profiling (low sputtering rate due to large illuminated area). Analysed samples differed with regard to surface morphology of the oxide layers, oxide layer compositions and thicknesses. An attempt was made to relate these differences to differences in post-thermal treatment procedures.

Effect of Weld Oxide on the Corrosion Resistance of Gas Metal Arc Welded Ferritic Stainless Steel Exposed to Simulated Exhaust Condensate

“…The percentage of Fe in the scale decreases with increasing temperature and the formation of Cr-rich layer depends on the temperature. Mandrino et al [24] reported that Fe 3 O 4 starts to form throughout Cr 2 O 3 layer at temperatures above 950°C and the mixture of two oxide phases delayed the formation of Fe oxide. Therefore, the growth of Cr 2 O 3 becomes predominant and the concentration of Fe decreases by dilution effect.…”

Initial oxidation of duplex stainless steel

“…The FWHM used for the metallic component was taken from the Cr and Fe peak measured after surface oxides were removed. The three and five oxides peaks, respectively, were expected to be present based on previous works [10,14,[38][39][40][41][42]. Fig.…”

Analysis Of Passivated A-286 Stainless Steel Surfaces for Mass Spectrometer Inlet Systems By Auger Electron and X-Ray Photoelectron Spectroscopy

“…In previous work [2] with passivated A-286, titanium was found at the surface in concentrations exceeding its bulk composition. Otherwise though, the A-286 depth profile [2] appears qualitatively similar to those seen in 300 series stainless steels [2,[4][5][6][7][8][9], with an adventitious carbon layer that is gradually sputtered away and an oxide layer that is indicative of the passivated layer [2,[4][5][6][7][8][9]. Previously, the oxide layer seen in A-286 was 4 nm [2].…”

“…Previously, the oxide layer seen in A-286 was 4 nm [2]. The oxide layers for untreated 300 series stainless steels ranged from 1 to 3.5 nm [4][5][6], while the oxide layer for specially treated 300 series stainless steels ranged from 25 nm to 2 microns thick [5][6][7][8]. Scanning electron microscopy (SEM) images from the 300 series stainless steels show a relatively smooth and flat untreated surface [4][5][6], except in reference [7], which shows a relatively rough surface for the untreated stainless steel.…”

“…Scanning electron microscopy (SEM) images from the 300 series stainless steels show a relatively smooth and flat untreated surface [4][5][6], except in reference [7], which shows a relatively rough surface for the untreated stainless steel. However, with passivation treatment, these surfaces become notably rougher [5][6][7] except for a flow polishing treatment in ref.[4].A-286 stainless steel coupons approximately 0.5" in diameter and 0.125" thick were passivated with five different surface treatments and an untreated coupon was left as a control. These surface treatments are being explored for use in mass spectrometer inlet systems, where it is very important to have inlet systems which do not change the composition of the analyte measured.…”