Cyclic Oxidation Behavior of 310 S Austenitic Stainless Steel at High Temperatures
Systematic study were undertaken to understand the high temperature oxidation behavior of AISI 310S Stainless steel. The tests were conducted at two temperatures of 930C and 960C up to 135 hours. A comparative study of weight gains for these two different temperatures was observed. The parabolic curve was found. From the nature of the curve (parabolic and other forms) one can able to under stand the nature of the oxide film formed on the substrate surface. A detailed investigation of microstructure revealed that the oxide film formed on the surface of the metal in the early hours undergoes spalling at 100 hours of cyclic oxidation. XRD studies of 135 hours cyclic oxidized substrate revealed the formation of chromium oxide layer but the layer formed is not completely stable over the entire surface. SEM investigation of oxidized sample confirmed the presence of cracks and spalling of oxide particles from the surface.
Fundamentals of High Temperature Corrosion
The sections in this article are 
 
 
Introduction 
High Temperature Corrosion in Technical Applications 
High Temperature Corrosion Resistance 
Fundamentals of Oxidation 
Stability of the Corrosion Product 
Formation and Growth of Oxide Scales 
Initial Stages 
Defect Chemistry 
Scale Growth by Solid State Diffusion 
Scale Growth Controlled by Mechanisms Other than Solid State Diffusion 
Specific Aspects of Oxide Scale Growth on Alloys 
 
 
Internal Oxidation/Corrosion 
 
 
The Influence of Mechanical Stress on Oxidation 
Stresses in Oxide Scales 
Mechanical Scale Failure 
Healing of Oxide Scale Cracks 
The Role of Internal Corrosion 
 
 
Chemical Scale Failure 
Sulfate Induced Hot Corrosion 
Vanadate Induced Hot Corrosion 
 
 
Corrosion Without the Formation of a Solid Scale 
Molten Phases as Corrosion Products 
Volatile Corrosion Products 
 
 
Gas Corrosion by Species Other than Oxygen 
Carburization and Metal Dusting 
Internal Carburization 
Metal Dusting 
 
 
Sulfidation 
Chlorination 
Water Vapor 
Hydrogen 
 
 
Experimental Techniques
The crystal structure of stilpnomelane. Part II. The full cell
Summary The structural formula of stilpnomelane averaged from 37 representative literature analyses and based on the determined structure is (Ca,Na,K)4(Ti0·1Al2·3Fe35·5Mn0·8Mg9·3)[Si63Al9](O,OH)216·nH2O. Ferrostilpnomelanes have up to 12 R 3+ cations in the octahedral sheet, ferristilpnomelanes commonly have between 24 and 30 R 3+ cations, rarely up to 37. The two groups can be distinguished by accurate X-ray powder diffraction, ferrostilpnomelanes having d 001 less and a greater than have ferristilpnomelanes. The unit cell is triclinic, a = b∼21·8 Å, γ = 120°, d 001∼12·2 Å, P . Hexagonal groups or ‘islands’ of 24 silicon-oxygen tetrahedra co-ordinate to the octahedral sheet, the centres of the ‘islands’ are displaced by 5a/12, 8b/12 on either side of the octahedral sheet as a result of warping of this sheet to permit articulation with the smaller tetrahedral sheet. The 24-tetrahedra ‘islands’ are linked laterally by 6-member rings of inverted tetrahedra, which in turn link at their apices to like rings connecting the next sheet of ‘islands’. Thus a single tetrahedral layer is 4 tetrahedra thick and has symmetry 6/m. The 6-member rings of tetrahedra act as hinges permitting up to 0·5 Å extension or contraction of the tetrahedral sheet to accommodate variations in the octahedral sheet dimensions with varying R 2+/R 3+ ratio.