Definition - What does Neutral Charge mean?
A neutral charge is the electrochemical occurrence where an atom has an equal number of electrons and protons. Such an atom is neither positively charged nor negatively charged because the protons and electrons balance each other out. The presence of a neutral charge in any system helps prevent or reduce corrosion on a metal's surface.
Corrosionpedia explains Neutral Charge
In order for corrosion to occur, ions must be transferred from an electrochemical cell to and from the metal's surface. Therefore, the existence of a neutral charge within such a system reduces the probability of an exchange occurring. In general, metals lose electrons to form positively charged ions and nonmetals gain electrons to form negatively charged ions.
When metal atoms are exposed to an environment containing water molecules, they give up electrons and become positively charged ions, provided an electrical circuit can be completed. This effect can be concentrated locally to form a pit or crack, causing pitting and/or crevice corrosion.