Effect of Surface Fe-Sn Intermetallics on Oxide Films Formation of Stainless Steel in High Temperature Water

The oxidation of stainless steel with Fe-Sn intermetallics adhesion in 300 °C water was studied by analyzing the morphologies and phase structures of surface oxide films. The oxidation behavior of stainless steel was discussed in order to illustrate the effect of Fe-Sn intermetallics on the oxidation characteristic. Larger size of faceted spinel and small size of SnO2 particles are observed on the samples with Fe-Sn intermetallics adhesion, whereas smaller faceted hematite and spinel grow on the samples without Fe-Sn intermetallics adherence. The surface intermetallics aggravates the spalling of oxide particles and decreases the corrosion resistance of stainless steel. Such deterioration is attributed to the loose microstructure characteristic and the poor corrosion resistance of SnO2 particles formed in high temperature water.

Oxidation Characteristics of Cr2O3-La2O3 and NiAl-La2O3 Coated on Ferritic Stainless Steel by Thermal Spray Method

The present works concerns in evaluating thermal oxidation characteristic of composite coating on ferritic stainless steel at high temperature application. SUS430 ferritic stainless steel was used as the substrate material whereas Cr2O3-La2O3 and NiAl-La2O3 were used as the coating material. Thermal spray has been used as the deposition method, whereas thermal oxidation at temperature of 750°C for 24, 48 and 96 hours has been employed on the coated material in the atmosphere environment. From the weight meausurement before and after thermal oxidation, it was observed insignificant weight losses, whereas this condition is stable for all the applied oxidation period. However weight losses is more on the NiAl-La2O3 as compared with Cr2O3-La2O3 samples, which is due to the morphological characteristic of the former layer as observed by scanning electron microscope (SEM) characterization. From X-ray diffraction (XRD) characterization, it was observed the formation of stable layer Cr2O3 for Cr2O3-La2O3 coated samples, whereas formation of NiO observed for the case of NiAl-La2O3 sample.

Coal Quality Characteristics and Inflaming Retarding Mode of Indonesia Coal in the Large Power Statdion

this paper introduces the main parameters of the mining and arrival coal quality, and analyzes the low temperature oxidation characteristic of Indonesia coal through thermogravimetric test; meanwhile, the mechanism of spontaneous combustion of Indonesia coal is clarified, the advantages and disadvantages of various inflaming retarding methods are compared, and the development direction of inflaming retarding of Indonesia coal in the power plant is pointed out.