We studied the corrosion inhibition properties of a combination of polyaspartic acid, polyepoxysuccinic acid, polyamino polyether methylenephosphonate, and sodium gluconate for carbon steel in recirculating cooling water. Characterization employed weight loss measurements, Tafel polarization, electrochemical impedance spectroscopy, X-ray fluorescence (EDX), and atomic force microscopy (AFM). The results show that the composite efficiently inhibited corrosion on carbon steel at relatively low dosages in severely corrosive soft water media. The EDX spectrum determined the nature of the adsorption layer on the steel surfaces. Scanning electron microscopy and AFM further confirmed the formation of a protective film on the carbon steel surface.