03-23-2019, 12:10 PM
RE bi-metal corrosion:
Depending on context, some people may refer to it as sacrificial anode protection. The sacrificial metal is more reactive, has more negative electro-potential than the metal it is protecting. Hence, the anode (one of the two dissimilar metals) is much more likely to corrode. However, I believe it has to be in the presence of an electrolyte like rain water and earth salts?
This is a reason why so many vehicle exhaust shields are found at road sides in the north and eastern states and provinces. The steel securing hardware did not fail, but the aluminum shield attached to the securing hardware corroded away.
Depending on context, some people may refer to it as sacrificial anode protection. The sacrificial metal is more reactive, has more negative electro-potential than the metal it is protecting. Hence, the anode (one of the two dissimilar metals) is much more likely to corrode. However, I believe it has to be in the presence of an electrolyte like rain water and earth salts?
This is a reason why so many vehicle exhaust shields are found at road sides in the north and eastern states and provinces. The steel securing hardware did not fail, but the aluminum shield attached to the securing hardware corroded away.