The Influence of Carbon Contents on the Corrosion Resistance of Plain-Carbon Steels in the Water Environments

Transcription

1 - - The Influence of Carbon Contents on the Corrosion Resistance of Plain-Carbon Steels in the Water Environments SobhiIIbrahim YasirAAbdullah Ass Prof Engineer Mech Eng Dept / College of Engineering / Mosul University Abstract Plain-carbon steels are considered to be the most widely used materials in engineering and industrial applications In this study wide range of carbon steels are used in the most common corrosion environments which are salt water and drinking water The weight loss method is used then corrosion rate is found to correlate with carbon percentage of steels The results indicate good correlation which are related to the microstructure where higher pearlite show higher corrosion rate and pearlitic steel represents the maximum corrosion rate This is found in both environments used where higher corrosion rate is the characteristic of salt water It is also found that the longer exposure time the lower corrosion rate while weight loss is still continuing Keyword Plain-carbon steelscarbon content Corrosion rates Water environments 9//7 9//

2 Al-Rafidain Engineering Vol8 No June (Corrosion environment) (Electrochemical) (Chemical reaction) (Wet Corrosion) (Electrolyte) (Anode) (Galvanic Corrosion Cell) [] (Single phase) (Mechanical (Hardness) (Tensile strength) (Corrosion) (Cathode) (Two phases) properties) [] (Microgalvanic corrosion cells) (Electrolyte) [] (Eutectoid Steels) (Corrosive media) () (Hyper- (Hypo-eutectoid Steels) eutectoid Steels) () ) ( % [7] ph (Localized breakdown) [98] ( ) %

3 (% C 8% C) [] (Han 8) (%C %C) [] (Melchers ) [] (Pillai 98) (% C % C) [] [] (Tomlinsion 98) ( Miroslav ) (Raja % ( % % %) (8%C %C) [] ) - SO - Cl - [] (Takasaki 7) (s) (Mild steels) (Larson and SO - Cl - Skold 98) - HCO Cl - - SO HCO ( (Cl - ) [7] (Garcia 8 ) (Conductivity ) Weight loss ) ( ) NaCl NaCl (% C) [] (Takasaki 7) (Macdonald (Mild steels) [8] 978) (%C) Ca + [9] (Moller 7) (8% C) (CaCo ) (Cl - ) [] (Corvo ) 7

4 Al-Rafidain Engineering Vol8 No June - () (Equilibrium heat- treatments) (Polishing) ( 8 ) % Nitric acid and 98% alcohol ) (% Nital) () (Etching) [] ( 8 9g % / () (NaCl) - (Close condition) g % ( ) ( ) 8

5 ) % C Steel ) % C Steel ) % C Steel ) % C Steel ) % C Steel ) % C Steel 7) % C Steel 8) % C Steel (a) 9) 8% C Steel (b) ) 8% C Steel ) % C Steel ) % C Steel (c) (X) (X) (X) (X) 87 (8% C) () 9

6 Al-Rafidain Engineering Vol8 No June () COMPOUND Total hardness mg/l Calcium hardness mg/l (Cl - )mg/l (Mg + ) (Ca + ) Electrical conductivity PH Electrode potential (Volt) SALT WATER DRINKING WATER () STEEL SAMP LE NO S S S S S S S7 S8 S9 S S CHEMICAL COMPOSITIONS (% WEIGHT) C Si Mn P S Cr Ni Mo Al Fe ( ml hydrochloric acid and g hexamethylene tetramine distilled water to make ml) [] ()

7 (Mils Per Year) / (T ) (Corrosion rate) (W) Corrosion rate ( mpy) = W DAT (A) (D) ( ) -[8] ( ) (mg ) (w) (g/cm ) (D) (in ) (A) (hours) (T) inch (mil) {a ) {ab ()} ( () } {b ()} (Microstructure) + ) [8] ( [8] ( + ) (Primary ferrite) [] (Intermetallic compound) ( + ) (Solid Solution) (Microgalvanic corrosion)

8 Al-Rafidain Engineering Vol8 No June 7 month months months months months % Fe % Carbon (a) 7 month months months months months % Fe % Carbon (b) (b) (a) () % [] (Different potentials) (Two phase structure) ( + ) (Nital)

9 {ab ()} [8] [] (Melchers ) [] { ab () } (Pillai 98) [] (Han 8) (Corrosion products layers) (Oxides protection layers) {abcde ()} [] [8] (Macdonald 978) [] (Azzerri 98) [] (Takasaki 7) [7] [9] (Yunping ) [8] (Nacl) (% Nacl) [9] (Yunping )

10 Al-Rafidain Engineering Vol8 No June Months (a) % % Months (b) % Fe % Carbon (b) (a) ()

11 7 7 8 Month 8 % Fe % Carbon (a) Months 8 % Fe % Carbon (b)

12 Al-Rafidain Engineering Vol8 No June Months 8 % Fe % Carbon (c) Months 8 % Fe % Carbon (d) Months 8 % Fe % Carbon (b) (d) (e) (e) () (a) (c)

13 () () Fontana G and Green D Corrosion Engineering rd Edition McGraw-Hill International USA pp 8-7 (98) Roberge PR Hand Book of Corrosion Engineering pp -88 () United States of America New York Van Vlack H Elements of Materials Science and Engineering th Edition Wesley Publishing Company Inc USA pp -79 (98) Shreir LL Jarman RA and Burstein GT edition Great Britain pp -7 () Corrosion Vol Corrosion Control Third (989) 7- " - - " " " (987) - Francis R Bimetallic Corrosion National Corrosion Service London UK pp 8-7 () Winston R Uhlig s Corrosion Handbook John Wiley & Sons Inc Canada pp 7-78 () Salem AH and Saber TM Inhibition of The Corrosion of Steel Pipes Carrying Potable Water Elsevier Science Publishers BV Amsterdam Vol9 pp-7 (99) Han L and Song S Ameasurement System Based on Electrochemical Frequency Modulation Technique for Monitoring the Early Corrosion of Mild Steel in Sea Water pp - 9 (8) 7

14 Al-Rafidain Engineering Vol8 No June Melchers R E Effect on Marine Immersion Corrosion of Carbon Content of Low Alloy Steels Journal of Corrosion Science Vol pp 9- () Pillai K C and Narayan R The Corrosion of Mild Steel in M M M HCL Journal of Corrosion Science Vol No pp -9 (98) Tomlinsion W J and Giles K The Microstructures and Corrosion of 79C Steel Tempered in the Range -7 C Journal of Corrosion Science Vol pp -9 (98) Mirosalv H and Mirosalv K Influnce of Carbides Over Some Steel Corrosion Acta University Vol pp - () Raja VS Baligidad RG and Shankar Rao V Effect of Carbon on Corrosion Behaviour of Fe Al Intermetallics in N Sulphuric Acid Journal of Corrosion Science Vol pp - () Takasaki S and Yamada Y Effects of Temperature and Aggressive Anions on Corrosion of Carbon Steel in Potable Water Journal of Corrosion Science Vol 9 pp -7 (7) Garcia KE and etal Lost Iron and Iron Converted in to Rust in Steels Submitted to Dry-Wet Corrosion Process Journal of Corrosion Science Vol pp 7-77 (8) Macdonald D D and etal Corrosion of Carbon steel during Cyclical Exposure to Wet Elemental Sulphur and the Atmosphere Journal of Corrosion Science Vol 8 pp 99- (978) Moller H The Influence of Mg + on the Formation of Calcareous Deposits on a Freely Corroding Low Carbon Steel in Sea Water Journal of Corrosion Science Vol 9 pp 99- (7) Corvo F and Minotas J Changes in Atmospheric Corrosion Rate Caused by Chloride Ions Depending on Rain Regime Journal of Corrosion Science Vol 7 pp () Higgins RA Engineering Metallurgy The English University PressLtd London UK pp - (999) ASTM G -9 Standard Practice for Preparing Cleaning and Evaluating Corrosion Test Specimens ASTM Washington USA pp -8 (999) Tomlinsion W J and Giles K The Microstructures and Corrosion of 79C Steel Tempered in the Range -7 C Journal of Corrosion Science Vol pp -9 (98) Principles of Corrosion Engineering and Corrosion Control Ahmad Z Technology Books pp 9-7 () Elsevier Science and 8

15 Bayliss DA and Deacon DH -7 () Steel Work Corrosion Control Second edition London pp Azzerri N and etal Assessment of Corrosion Rate of Steel in Sea Water by Polarization Resistance Technique Journal of Corrosion Science Italy Vol No pp (98) Louis F Jack T and Henry L Prediction of Corrosion Defect Growth on Operating Pipelines Trans Canada Pipelines Ltd Canada () Salem AH and Saber TM Inhibition of The Corrosion of Steel Pipes Carrying Potable Water Elsevier Science Publishers BV Amsterdam Vol9 pp-7 (99) Yunping X and Zhaohui X Corrosion Effect of Magnesium Chloride and Sodium Chloride on Automobile Components University of Colorado USA Report No CDOT-DTD- R-- () 9