High Temperature Corrosion of Chromium–Manganese Steels in Sulfur Dioxide

Abstract

This work was aimed at explaining the corrosion mechanism of commercial Cr-Mn steels at 1073, 1173 and 1273 K in the atmospheres containing oxygen and sulfur. Three steels were selected for the investigations, two singlephase austenitic steels (Cr17Mn17 and Cr13Mn19SiCa) and a two-phase austenitic-ferritic steel Cr15Mn19. On all studied steels triplex scales were formed. The inner very thin, fine-grained part of the scale contained manganese, chromium and iron sulfides and oxides, the intermediate layer was built mainly of the MnCr 2 O 4 spinel while MnO was the predominant constituent of the outer scale layer. According to the gravimetric measurements, after an initial incubation period, the oxidation of steel follows a parabolic rate law. Thermodynamic and kinetic aspects of the formation of oxide-sulfide and oxide layers were discussed. Oxidation was accompanied by depletion of the subscale region of the metallic core in manganese, which is the austenite former. Consequently austenite transformed into ferrite.

Real time observation of high temperature oxidation and sulfidation of Fe‐Cr model alloys

“…Comprehensive studies on the scale formation mechanism of an outer mixed oxide/sulfide layer on ferritic alloys aged in an oxidizing and sulfidizing atmosphere were previously presented in various publications . Previously published work mainly proposed the aging mechanisms after long time aging experiments and did not focus on the initial reaction.…”

“…The present flue gases produced during combustion are highly reactive and contain corrosive components like carbon dioxide, oxygen, water, and sulfur dioxide. Comprehensive efforts have been made to study scale formation in ferritic‐martensitic high temperature alloys in flue gas and sulfurizing atmosphere by means of long time corrosion experiments ( t > 250 h) . The formation of an inner and outer scale in relation to the former metal surface are well known, whereby the microstructure and phase composition of the scale strongly depends on the Cr‐content of the alloy.…”

Modelling and experiment of selective oxidation and nitridation of binary model alloys at 700 °C – The systems Fe, 1 wt.%{Al, Cr, Mn, Si}

“…Hence, research in this field is very multidisciplinary, spanning a broad range from water vapour assisted corrosion processes in boiler steels [1][2][3], steam turbine blades [4][5][6] or jet propulsion engines [7,8] to extremely corrosive mixtures (SO x ; NO x ; HCl or molten salts) in waste incineration plants [4,[9][10][11]. Ferritic steels containing aluminium, chromium or silicon, especially for electric heating devices (e.g.…”

Effects of calcium in ash on the corrosion performance of Ni-based alloys in simulated oxy-fuel environment

“…Radiometric analysis has indicated that the inward transport of sulfur is primarily due to the SO 2 /S 2 molecular transport. Sulfides were observed in the inner scale layer [6]. However, the effect of sulfur on corrosion in an oxy-fuel system has scarcely been studied [7].…”