アルミニウム製器物の腐食発生に及ぼす水質の影響

抄録

The aluminum kettles used in Noboribetsu in Hokkaido leaked in around one year or so. The leakage was caused by corrosion attacks at the bottom of the kettle. The characteristics of corrosion behavior were investigated by SEM, EPMA and electrochemical measurements. The EPMA analysis showed that some ions such as silicate, calcium and sulfate ions dissolved in tap water deposited on the anodized film. The deposited water glass with various contents of silicon and calcium elements causes cracks in the anodized film, which makes the adherence between anodized layer and aluminum substrate weaker and more brittle. The electrochemical measurement reveals that as the temperature becomes higher and concentration of the dissolved ions increases, the anodic polarization resistance of aluminum becomes lower.