TDS Measurement of Hydrogen Released from Stainless Steel Oxidized in H₂O-Containing Atmospheres

Abstract

Abstract. Hydrogen dissolved in the Cr 2 O 3 scale formed on the stainless steel in the H 2 O-containing atmospheres is observed by TDS (thermal desorption spectroscopy) measurements. The amount of dissolved hydrogen in the Cr 2 O 3 scale reaches a maximum about 0.32 mol% when the H 2 O concentration in the gas reaches 20%. It was found from GDS (glow discharge spectroscopy) measurements that hydrogen may exist at the oxide scale / substrate interface or in Cr 2 O 3 scale bounded that interface. However, results from the Vickers hardness and the observation of scale morphology by SEM (scanning electron microscopy), hydrogen dissolved in the Cr 2 O 3 scale would have little effect on a decrease in the mechanical property of the Cr 2 O 3 scale. Therefore, hydrogen dissolved in the Cr 2 O 3 scale may not be main factor of the deterioration of the Cr 2 O 3 scale.

Insight into a high temperature selective oxidation of HP40 alloy under a H2–H2O environment

“…24,25 When Cr cations cross metal/oxide interface to facilitate oxide scale growth, H-species would support Rahmel-Tobolski mechanism in pores at metal/oxide interface and subsequently close pores at the interface. [23][24][25] Similar enrichments of hydrogen at metal/oxide interface of alloy were also found in other researches involving H 2 O-containing atmosphere. 23,24 [11][12][13] Therefore, alloy oxidized under this condition is considered to have favorable performance in thermal cracking environment.…”

“…[23][24][25] Similar enrichments of hydrogen at metal/oxide interface of alloy were also found in other researches involving H 2 O-containing atmosphere. 23,24 [11][12][13] Therefore, alloy oxidized under this condition is considered to have favorable performance in thermal cracking environment. Raman spectrum is sensitive to crystal structures and has small penetration depth, therefore it can well characterize the phase structure on the surface of oxide scales.…”

“…It has been reported that hydrogen can dissolve into chromia scales formed in water-containing environment. [22][23][24][25] In order to see hydrogen distribution in oxide scales, GD-OES measurements were carried out for alloy samples oxidized for 0.2-20 h. GD-OES depth proles of oxide scales formed under H 2 -H 2 O environment aer various isothermal oxidation times are displayed in Fig. 5.…”

“…The existence of hydrogen at the surfaces probably caused by water adsorption and the reaction of water and oxides. 23,26 It was reported that the oxide structure formed on alloy surface was a poor barrier to H-species penetration, and Hspecies probably originated from H 2 O for chromia scale growing at low oxygen partial pressure environment created by H 2 -H 2 O. 24,25 When Cr cations cross metal/oxide interface to facilitate oxide scale growth, H-species would support Rahmel-Tobolski mechanism in pores at metal/oxide interface and subsequently close pores at the interface.…”

Investigation into the failure mechanism of chromia scale thermally grown on an austenitic stainless steel in pure steam

“…During the process of steam oxidation, the resultant hydrogen may flow into steam or diffuse into the oxides and metal substrate. Several published works employed Secondary Ion Mass Spectrometry (SIMS) [30,31] and Thermal Desorption Spectroscopy (TDS) [32] to study the hydrogen uptake in chromia scales formed in water vapor containing gas, and indicated the highest hydrogen concentration at the metal/oxide interface. Although no currently used techniques can distinguish the value state of hydrogen in the oxides, Norby et.…”