High-temperature corrosion of iron and iron-based alloys in sulfur-containing atmospheres

Technical Report · Fri Apr 01 04:00:00 EST 1983

OSTI ID:6167476

Yang, F C

The corrosion morphology, kinetics, and mechanism of the attack on metals and some iron-based alloys by sulfur-containing atmospheres are studied at 871/sup 0/C. In the case of pure iron, protrusions with sulfide-rich cores are observed on the scale surface. This morphology is explained by the fast transport of iron ions through the sulfide-rich streaks. Models of unbalanced diffusion are proposed to account for the formation of an inner porous layer. The addition of alloying elements, such as Al and Cr, improves the corrosion resistance by forming a protective Al/sub 2/O/sub 3/ or Cr/sub 2/O/sub 3/ oxide scale. However, sulfur penetration through the scale and its effect on the spalling resistance of the oxide scale can lead to the onset of a catastrophic corrosion and rapid failure of the alloys. The transport of sulfur through scales, the thermodynamic conditions for the formation of duplex oxide-sulfide scales and the influence of alloying elements are discussed. It is concluded that sulfur penetration through both performed and growing Al/sub 2/O/sub 3/ and Cr/sub 2/O/sub 3/ scales resulting in an accelerated attack is inevitable. Nevertheless, ways of slowing down the attack are recommended.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6167476
• Report Number(s): LBL-16089; ON: DE83013843
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
AUGER ELECTRON SPECTROSCOPY
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM
CHROMIUM ALLOYS
CORROSION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
IRON
METALS
NONMETALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
SCALING
SPECTROSCOPY
SULFIDATION
SULFIDES
SULFUR
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE