A dispersion-strengthening Fe-Cr-Al oxidation-resisting alloy has been made by means of spray-dispersion method which oxide particles are sprayed into molten steel. The oxide particle's effection upon crystal growth at high temperature, tensile strength and toughness, impact fracture shape, high temperature oxidation as well as mechanical properties at high temperature, have been studied. The results indicate that the oxide particles are effective in preventing the trend of the crystal growth at high temperature, and this action that the oxides obstruct the movement of the grain boundaries becomes more striking at higher temperature. There is also a rise in strength and toughness of Fe-Cr-Al alloy with oxide particles and that σ_(0.2) and σ_b increase in the range of 167-178MPa and 129-146MPa, respectively, and a_k increases in the range of 2.62-5.29J/cm~2, this may be considered to the oxide particles preventing the movement and prolifiration of dislocations. Oxides have changed the fracture shapes, the alloy with spraying oxides shows cleavage and ductile dimple cracking and cleavage fracture without oxides. The accelerated oxidation at 1100 ℃ and the rapid heating life test at 1250 ℃ of three alloys: (A) Fe-25Cr-5Al (B) Fe-25Cr-5Al-CeO_2 (C) Fe-25Cr-5Al-ZrO_2, have been examined, and the oxide scales have been observed by SEM. EPMA and X-ray diffraction. It is shown that oxides contribute to a decrease of oxidation rate of the accelerated oxidation which oxidation kinetics conforms to parabolic. Oxides have no infulence upon the phases of the scale but have changed the multi-layer structure of it, exerted correspondingly good influence up the adhesivity and density of the scale and given a control over the presence of the cavities at the scale/substrate interface. Such may be concluded that oxides prevent Al ions from diffusing in the scale and eliminate the facts that destroy the adhesivity and density of the scale and give it a tight adherency to the substrate. The rapid heating life test shows: the oxides remarkably increase the rapid heating life, the addition of oxides makes the life above 86.2% and 66.7% comparision with no spray-alloy, respectively, and the total percentage elongation at the end of test decreases to greater extent. The oxides are found to exert notably good influence up the mechanical properties of the Fe-Cr-Al alloy at high temperature oxidation, such may be very important to increase the heating life of Fe-Cr-Alalloy.
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