Text Box: “INTERNAL CORROSION OF THE COOLING SYSTEM, CORROSION MECHANISMS AND INHIBITORS MODULE” © ISBN 0-9720927-5-7 TTS Publication No. 107 List price US $15.00 NOTE: This module is extracted from “The Engine Cooling System” and/or “Engine Coolants” The module DOES NOT provide information in addition to that contained in the books. Text Box: TABLE OF CONTENTS Corrosion considerations of the cooling system Corrosion as a natural process Corrosion of ferrous and non-ferrous metals Electrochemical corrosion Galvanic series of metals Electrochemical corrosion processes Anodic and cathodic reactions Corrosion cells: Bi-metal and single metal cells Electrical conductivity of electrolytes Sources of electrical currents in the cooling system Acidity / alkalinity (pH) Effect of pH on the corrosion of metals Reserve coolant alkalinity Survey of coolant pH Effect of pH and electrical potential Electrolysis Electrolysis demonstration with conventional and organic acid coolant Pitting, crevice, solder bloom and uniform corrosion Liquid erosion, cavitation Liquid erosion, impingement Laminar and turbulent flows Erosion patterns in radiator tubes Effect of dissolved mineral salts (from the water) on corrosion Effect of dissolved oxygen and combustion gas on corrosion Effect of relative surface areas on corrosion Effect of aggressive ions on corrosion Effect of metal temperature and heat transfer rates on corrosion Effect of homogeneity of the tube material on corrosion Effect of deposits on corrosion Copper/brass corrosion Aluminum corrosion CORROSION INHIBITORS Corrosion inhibition Evolution of inhibitor formulations Anodic, cathodic and adsorption inhibitors Silicate, Amines, Nitrite, Nitrate, Borate, Phosphate, Molybdate Carboxylic Acids + polymers Inhibitor / Function Summary chart