Abstract
ASTM SA 210 GrA1 steel is used for many different applications of steam-generating systems in thermal power plants because of its resistance to corrosion at elevated temperatures and low cost of production. This study examines the oxidation behavior of tungsten inert gas (TIG) weldment in GrA1 boiler steel. Different regions of the weldment were identified by optical microscopy. The oxidation studies were then performed about heat-affected zone (HAZ) and weld metal specimens of TIG weldment after exposure to air at 900°C under cyclic conditions. The thermogravimetric method was applied to observe the kinetics of oxidation. X-ray diffraction and scanning electron microscopy with energy-dispersive X-rays techniques were used to analyze the oxidation product. The HAZ region confirmed the presence of moderately more oxidation (in terms of weight gain of 145.045 mg/cm2) than that of weld metal (139.797 mg/cm2) because the formation of the thick porous oxide scale had internal voids to a high extent.
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