A SURVEY OF SEA WATER CORROSION OF ALUMINIUM-MAGNESIUM ALLOY IN THREE SEA AREAS
LF6M铝镁合金海水腐蚀规律研究及异常数据处理

By regression analysis of the corrosion results of the LF6M aluminium-magnesium alloy fully immersed in seawater for 8 years, the corrosion data may be described with the following two formulas: (1) A = m' tn (2) Dmax = a+b logt with A represerting corrosion rate and Dmax the maximum depth of pits. A special phenomenon was noted that in the seashore of Xiamen the clad may act as sacrificial electrode and the base alloy as cathode was protected by the formes. The morphological characteristics of the specimens seriously corroded were examined by using SEM, TEM, EDXA and X-ray diffraction techniques. The result indicates that the exfoliative corrosion of the alloy is related to MnAl6 precipitates which distribute as continuous chain along grain boundaries.