アルミニウム合金A6N01-T5の腐食形態に及ぼす組織の影響

概要

論文の詳細を見る
Corrosion behavior of the industrially manufactured materials of an Al-Mg-Si alloy A6N01 was investigated for a soak in synthetic seawater at 40℃ for 20 days. Microstructural analyses were also carried out by electron probe microanalyzer (EPMA) and X-ray diffractometry (XRD). Although the chemical compositions and mechanical properties were within the limit prescribed in the standard (JIS), a wide variation of the microstructure was observed probably depending on manufacturing process including both mechanical and heat treatments. The materials were characterized by the detailed analyses of the precipitates in the aluminum matrix. In particular, distribution of magnesium and crystallography of the precipitates were indicative for this characterization. SEM (scanning electron microscope) observations of the surface of the materials after the soak revealed that the corrosion morphologies of these materials were categorized into three types including large micropitting with a slight intergranular corrosion, general corrosion and intergranular corrosion with connected small micropits. These morphologies correlate with microstructural features probably because the local-action cell formation depends on the distribution of additive elements in the aluminum matrix.
社団法人日本船舶海洋工学会の論文