What metal corrodes with water?

Answer 1

All of them, to a greater or lesser degree, depending on their position in the "Electromotive Series of Metals," also known as the "Galvanic Series of Metals." This is a list of metals in order from most to least reactive in sea water. If there are two metals near each other in salt water, the one which is the more reacive (a.k.a. "least noble") will corrode, thus protecting the other metal. This is why ships often put chunks of zinc (called "zinc lozenges") near the propeller---without the zinc, the steel hull would corrode very quickly as it is more reactive than the bronze propeller. The zinc is more reactive than steel even, so it will do all the corroding and the hull is protected. Of course you have to replace your zinc lozenges periodically, as they will corrode away to nothingness eventually. Here is a simple one: From Most Noble (Protected Metals) to Least Noble (Corroded Metals): Mercury Vanadium Gold Silver Monel Nickel Passivated Stainless Steel (rare type) Copper Brass Tin Lead Active Stainless Steel (most common type) Cast Iron Steel Aluminum Zinc Magnesium You see that zinc is quite low on the list, and will corrode first and thus protect everything above it. Stainless steel is higher than ordinary steel---it stays stainless by forcing everything below it (like ordinary steel) to do the corroding. However, if you put stainless steel alongside nickel in salt water, the stainless will do the corroding and the nickel will be protected. Fancier lists include more metals and alloys of different metals. Some links to corrosion and the electromotive series of metals: http://en.wikipedia.org/wiki/Galvanic_series http://www.corrosion-doctors.org/Definitions/galvanic-series.htm http://www.experiencefestival.com/a/Corrosion_-_Electrochemical_theory/id/1262459

Answer 2

The most common example is iron, with the presence of oxygen.