Methods of employing corrosion inhibitors with oxidizing and/or non-oxidizing biocides, such as peroxycarboxylic acids, to provide corrosion protected compositions are disclosed. Various corrosion inhibitors further provide biocidal efficacy in addition to the corrosion protection providing further benefits for application of use. Methods of employing corrosion protected biocide compositions, such as peroxycarboxylic acid compositions, for corrosion protection are particularly well suited for treating fluids intended to flow through pipes, namely in the energy industry, water and paper industries, etc. Methods providing suitable corrosion protection in comparison to untreated systems and corrosion protected systems using conventional corrosion inhibitors, such as quaternary amines and imidazolines commonly used in the industry, are disclosed.