Al-8%Fe P/M材の強度と耐食性に及ぼす加熱処理の影響
1992 年 42 巻 5 号 p. 281-286
詳細
1992 年 42 巻 5 号 p. 281-286
Strength and corrosion resistance of an extruded Al-8%Fe P/M alloy has been investigated. Corrosion tests were carried out in a 3.5% NaCl aqueous solution kept at 40°C. Almost no change in the microstructure and strength was observed after heating up to about 400°C, while coarsening of structure and softening occurred above 400°C. The corrosion rate became minimum at a heating temperature of 200°C. The corrosion rate of as-extruded alloy was high in the early stage of corrosion, probably because of the residual stress. Since the residual stress is released by the pitting corrosion, the corrosion rate decreases in the later stage. The high corrosion rate observed after heating at higher temperature is considered to be due to the coarsening of structure and the increase in electrochemical nonuniformity.
