AZ91Dマグネシウム合金の大気中における異種金属との接触腐食挙動 Atmospheric galvanic corrosion behavior of AZ91D coupled to other metals
The high purity magnesium alloy AZ91D has demonstrated superior corrosion resistance to the atmosphere, when compared with commercial alloys previously available. Magnesium is anodic to all other engineering metals and has no defense against galvanic corrosion when a magnesium-dissimilar metal assembly is exposed to salt water or other electrolyte. Although galvanic couples are unavoidable in most practical applications of magnesium, there are very few reports about galvanic corrosion of magnesium alloys coupled to other metals. Atmospheric galvanic corrosion test was done to get basic data about the galvanic corrosion behavior of magnesium alloys coupled to dissimilar metals and alloys. This paper reports the results of atmospheric galvanic corrosion test of magnesium alloy AZ91D coupled to a number of dissimilar metals and alloys in Asahikawa, Choshi, Miyakojima and Kayamajima. According to our result this time, it appears the mild steel and SUS304 stainless steel accelerate and anodized aluminum alloys reduce a galvanic corrosion of magnesium alloys. And the corrosion area of atmospheric galvanic corrosion of magnesium alloys were in and around dissimilar metals. We obtained similar results by electrochemical measurements in chloride solution of the magnesium alloy AZ91D and mild steel or SUS304 stainless steel.
軽金属 49(4), 172-177, 1999-04-30
The Japan Institute of Light Metals