Definition - What does Brass Corrosion mean?
Brass corrosion occurs when the components of the brass alloy, such as zinc, copper and tin, corrode when they come in contact with water. Since brass typically contains a significant amount of zinc, it is susceptible "dezincification" or the corrosion of that zinc. The zinc will selectively corrode in the alloy, leaving behind only a weak shell consisting of the remaining copper. Corroded brass that has been "dezincified" can be identified by a splotchy reddish or pink coloring. Brass is susceptible to other forms of corrosion caused by different chemicals, such as ammonia or mercury, that attack the brass causing it to weaken.
Corrosionpedia explains Brass Corrosion
Brass is an alloy of cooper, zinc and small amounts of tin. The zinc component of brass is easily lost when it comes into contact with water, causing the brass to easily corrode. This occurs when the zinc corrodes, leaving a copper shell remaining, that is generally quite weak. Generally, corrosion resistance decreases and the concentrations of zinc increases in an alloy. To prevent brass corrosion caused by the corrosion of the zinc component, the zinc content can be kept below 15% and small amounts of tin can be added to the alloy. Brass should never be used in raw-water applications since it is so susceptible to corrosion. Brass corrosion can be prevented by using sacrificial anodes that will corrode before the brass itself does. It is also important to vigilantly monitor brass to further prevent corrosion.