Factors influencing the rate of corrosion Corrosion and Potable Water Quality of Majmaah Region, North Riyadh – KSA Research Centre: Engineering and Applied Sciences Shemy M. Ahmed, Sameh S. Ahmed, Ehab A. Abdelhafiz, Hassan I. Mohamed (1) Mechanical Engineering Department – College of Engineering (2) Civil Engineering Department – College of Engineering Kingdom of Saudi Arabia Ministry of Higher Education Majma’ah University 1432/2011 Pitting Project Objective Localized pitting corrosion has been recognized as a source of water system equipment failure The aim of the present work is to investigate the effect of different tap water resources in North Riyadh on the Localized pitting corrosion morphology of carbon steel. Cast iron pipe without any protection from pipe corrosion (pipe burst, poor water quality customer compliant) Corrosion: The destruction or the deterioration of a material that occurs due to reaction with its environment. Types of Corrosion Impact of corrosion: Costly system repairs and replacements Disruption of service Structural and environmental damage Reduced water quality Improper treatment Discolored water (red, brown or blue), Decreased system capacity Uniform Pitting Stress corrosion Corrosion Fatigue Dissimilar metal Concentration cells Crevice Stray current Dezincification Graphitization Impingement attack Cavitations Factors influencing the rate of corrosion Schematic layer structure in aged unprotected cast iron and steel pipes ( Bohlar et al, 2005) Bimetallic couples Stressed areas Conductivity Aeration Ion concentrations pH Temperature Flow rate and turbulence Anaerobic bacteria 2nd Phase: Experimental Work Immersion test Test material Collective of water analysis Test times, 3, 5, 7, 9 hours 3rd Phase: Results Microscopic observation Data analysis Macrograph pictures of corrosion products formed in aged pipe internal surfaces which were established over decades in the actual TBW pipe distribution systems receiving conventional Groundwater (G1) treated by aeration, disinfection, and pH stabilization:(a) Unlined cast iron, (b) Galvanized steel © Lined iron (d) PVC. 4th Phase: Report writing Macrographs of the failed tube samples (a) outer surface and (b) Inner surface