what is "galvanic action"?

Galvanic Action 电耦作用
When iron and steel are subject to conditions of aqueous corrosion the incidence and rate at which the corrosion takes place will alter if the steel is coupled with other metals or alloys that are also exposed to the electrolyte. Copper, brass, bronze, lead and nickel are more “noble” and act as auxiliary cathodes to the steel and accelerate its anodic dissolution, that is, its corrosion. Magnesium, zinc and zinc-base alloy are nearly always less noble and tend to divert the attack from the steel to themselves. The galvanic relationship of various metals is an important factor affecting corrosion.

定义: 当钢在含水的情况下发生腐蚀﹐腐蚀的程度将受到和钢结合一起并暴露于电解质的其它金属或合金的影响。 铜, 黄铜, 古铜, 镍，其他贵族金属作为负极将加速对作為正极的钢的溶解。含镁和锌的合金則可使钢免受腐蚀。 各种各样的金属电耦关系是一个影响腐蚀的重要因素.


2007-01-08 02:37:50 補充：
不過你個講法都0岩不一定要係鋼的galvanic action -- A form of corrosion which occurs when dissimilar metals in contact with each other and with an electrolyte causes one of the metals to dissolve and go into solution.