AM60镁合金大气腐蚀及动力学分析

Atmospheric Corrosion and Dynamic Analysis of AM60 Mg Alloy

摘要:

本文研究了铸态和挤压态AM60镁合金在太原地区的大气腐蚀行为。试验结果表明铸态合金的腐蚀速率高于挤压态合金。铸态合金中的共晶组织比α-Mg更具耐大气腐蚀能力，但是这导致了共晶相周围的α-Mg相腐蚀严重，且腐蚀产物膜也不均匀保护性差。挤压态合金的最大腐蚀深度要远小于铸态合金。挤压态合金的显微组织比铸态更加均匀，而且不含有共晶组织，导致挤压态合金表面的腐蚀产物膜更加致密也更具有保护性。挤压变形不会引起AM60镁合金大气腐蚀性能的下降。

Abstract:

Atmospheric corrosion behaviour of cast and as-extruded AM60 Mg alloy was studied in this paper. The results showed that the corrosion rate of cast alloy was higher than that of as-extruded alloy. α-Mg-Mg17Al12 eutectics in cast alloy had better corrosion resistance than α-Mg phase in outdoor atmospheric environment, which would lead to the α-Mg phase being corroded seriously than the nearby eutectics. Then, the corrosion films on as-extruded alloy would not be uniform and had a poor protective effect. The maxium depth of corrosion pit in as-extruded alloy was deeper than that in cast alloy. The as-extruded alloy had much uniform mircrostructures and did not contain eutectics than cast alloy, which caused the corrosion film formed on surface of the former had better protection effect than that on the latter’s surface. Extruded process can not lead to a decrease in atmospheric corrosion resistance of AM60 Mg alloy.