Sulfidation and hot corrosion of materials at elevated temperatures

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5365029

Pettit, F S; Meier, G H ^[1]

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1. Univ. of Pittsburgh, PA (USA)

Degradation of alloys can occur when they are exposed to sulfur-bearing atmospheres and can also be observed in oxygen-containing atmospheres if sulfur can penetrate otherwise protective oxide scales. In some cases the formation of sulfides can result in catastrophic corrosion, particularly if the temperature is above the melting point of the sulfide. The mechanisms whereby sulfur affects the high temperature corrosion of alloys is described with respect to alloy composition, temperature, and atmosphere composition. Hot corrosion attack of alloys is caused by the development of liquid deposits upon the surfaces of alloys. Such conditions are frequently encountered when materials are used in combustion environments. The deposits in conjunction with the gas environment can result in the formation of nonprotective corrosion products and hence very substantially increased corrosion rates compared to those observed in the absence of the deposit. The hot corrosion attack of alloys is described by first considering the degradation sequence and how the important features of this sequence are affected by the important experimental variables. It is shown that hot corrosion processes can be viewed as being composed of initiation and propagation stages. The distinguishing characteristics of these two stages are critically dependent upon a number of factors of which the composition of the alloy, the deposit and the gas environment are the most important. The hot corrosion degradation processes are compared for nickel, cobalt and iron base alloys and the effects of different alloying elements are examined.

• OSTI ID: 5365029
• Report Number(s): CONF-840909--
• Conference Information: Journal Name: TMS (The Metallurgical Society) Paper Selection; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COBALT ALLOYS
COBALT BASE ALLOYS
COMBUSTION
CORROSION
CORROSION PRODUCTS
CORROSIVE EFFECTS
DEPOSITS
ELEMENTS
FLUIDS
GASES
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
MELTING
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONMETALS
OXIDATION
PHASE TRANSFORMATIONS
REACTION KINETICS
SULFIDATION
SULFIDES
SULFUR
SULFUR COMPOUNDS
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES