Velocity Assisted Corrosion Of Api X 52 Steel In 3

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The presentation deals with our study on the velocity affected corrosion of a line=pipe steel, API-X52 in sea water environment.

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  • thanks prof. for this intresting presentation it really 'll help me in my research& i really hope 4 more contact with u
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  • Hello! I congratulate you for your excellent presentation. It’s really interesting. I add your presentation as a favorite, I hope you visit my presentation, and also add me to your favorites. Thanks, greetings from Venezuela http://www.slideshare.net/jesusd411/microsoft-office-nuestro-estilo-de-vida-3202387 Add me to your Favorites click on the heart that says Favorite. Thanks
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  • Thanks for your comments. Would appreciate greatly if you kindly send me details of your new materials.. Regards.
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  • Thanks for sharing this... Very specialised, but interesting to me all the same. My company manufactures and sells plain bearings. In hydrodynamic fluid film lubrication regimes, where the system is unstable/turbulant or where the externally applied dynamic loads are too high, we sometimes see cavitation erosion of the plain bearing surface. General erosion can also sometimes be a problem in conditions where the fluids move over the bearing surface at high velocity. We have therefore specialised in developing erosion- and cavitation erosion- resistant materials; and with considerable success I might add!
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Velocity Assisted Corrosion Of Api X 52 Steel In 3

  1. 1. VELOCITY-ASSISTED CORROSION OF API X-52 STEEL IN 3. 5 % NaCl SOLUTION DR. AMARNATH & PROF.T. K. G. NAMBOODHIRI DEPT. OF METALLURGICAL ENGINEERING, BANARAS HINDU UNIVERSITY
  2. 2. INTRODUCTION <ul><li>Corrosion of metals in fluids enhanced by relative velocity of corrodent </li></ul><ul><li>Corrosion increases with increasing velocity, first by mass-transfer and then by surface shear forces.- Laminar flow. </li></ul><ul><li>In turbulent systems impingement attack and cavitation damage lead to increased corrosion. </li></ul>
  3. 3. EROSION-CORROSION IN AQUEOUS SYSTEMS EROSION- CORROSION VELOCITY-ASSISTED CORROSION IMPINGEMENT ATTACK CAVITATION-DAMAGE
  4. 4. EFFECT OF VELOCITY ON MASS LOSS
  5. 5. VELOCITY- ASSISTED CORROSION UNDER LAMINAR FLOW
  6. 6. IMPINGEMENT ATTACK-TURBULENT FLOW <ul><li>Under turbulent flow high velocity impact of fluids leads to removal of material </li></ul><ul><li>Stress created by fluid impact crack or remove corrosion product films and expose fresh metal </li></ul>
  7. 7. CAVITATION DAMAGE <ul><li>Pressure variations in flowing liquids lead to formation of bubbles or cavities. </li></ul><ul><li>Under high pressure, these bubbles collapse violently and damage nearby surface. </li></ul>
  8. 8. AIM OF THE PAPER <ul><li>Line-pipe steels like API X-52 are used for large diameter pipelines carrying crude, natural gas and petroleum products over large distances, often under the sea. </li></ul><ul><li>Exposure to high velocity fluids within and the dynamic sea-environment outside make these pipelines susceptible to erosion-corrosion. </li></ul><ul><li>This paper evaluates the erosion-corrosion behaviour of API X-52 in flowing 3. 5 % NaCl solution </li></ul>
  9. 9. Experimental <ul><li>Commercial API X-52 supplied by SAIL R&D, Ranchi as 10 mm thick hot rolled plate. Table 1- chemical composition </li></ul><ul><li>Strips hot rolled to 2. 5 mm at 850 C. Some strips cold rolled to 10, 30 and 50 % reductions. Some strips annealed at 950 C, furnace cooled or water quenched and tempered at 150 C </li></ul><ul><li>Immersion tests for general corrosion. Exposure on a parallel disk rotating assembly for velocity effects. Weight loss measurements. </li></ul>
  10. 10. TABLE 1:CHEMICAL COMPOSITION OF API X-52 STEEL Nominal Composition, Weight % Balance 0. 05 0. 04 0. 026 0. 027 0. 20 1.25 0. 15 Fe V Nb S P Si Mn C
  11. 11. PARALLEL DISK ROTOR
  12. 12. RESULTS <ul><li>Mechanical Properties, Table 2 </li></ul><ul><li>Microstructures </li></ul><ul><li>STATIC CORROSION: TABLE 3 </li></ul><ul><li>VELOCITY-ASSISTED CORROSION </li></ul>
  13. 13. Table 3 Mechanical properties of API X-52 steel <ul><li>conditions YS UTS % el Hardness </li></ul><ul><li> (MPa) (MPa) (VPN) </li></ul><ul><li>As-received 476 595 30.0 180 </li></ul><ul><li>10 % cold rolled 580 620 4.13 312 </li></ul><ul><li>30 % cold rolled 610 679 2.40 339 </li></ul><ul><li>50 % cold rolled 695 765 1.06 363 </li></ul><ul><li>Q & T. 639 972 10.3 389 </li></ul><ul><li>Annealed 297 481 31.95 134 </li></ul>
  14. 14. MICROSTRUCTURE OF API X-52 <ul><li>As-received (hot rolled) steel </li></ul>
  15. 15. MICROSTRUCTURE OF API X-52 <ul><li>Annealed </li></ul><ul><li>Quenched & tempered </li></ul><ul><li>10 % cold rolled </li></ul><ul><li>30 % cold rolled </li></ul><ul><li>50 % cold rolled </li></ul>
  16. 16. Table 3. Static corrosion of API X-52 steel 3.5% NaCl, 20 days’ exposure <ul><li>Conditions Corrosion </li></ul><ul><li>Rate, mdd </li></ul><ul><li>Hot rolled 20 </li></ul><ul><li>Annealed 23 </li></ul><ul><li>Quenched & tempered 13 </li></ul><ul><li>10 % Cold rolled 18 </li></ul><ul><li>30 % Cold rolled 14 </li></ul><ul><li>50 % Cold rolled 19 </li></ul>
  17. 17. VELOCITY-ASSISTED CORROSION <ul><li>API X-52 Steel, as-received, 3. 5 % NaCl </li></ul><ul><li>Variation of corrosion rate with time at three velocities </li></ul><ul><li>Corrosion rate increases with increasing velocity </li></ul>
  18. 18. VELOCITY ASSISTED CORROSION <ul><li>Corrosion rate (Hot rolled steel) increases with increasing velocity (0. 11 m/s to 4. 62 m/s) </li></ul><ul><li>At velocities above 400 RPM(0. 86 m/s), the corrosion rate was found to be more than that for a rotating cylinder with laminar flow. (Erosion-corrosion) </li></ul>
  19. 19. EFFECT OF THERMAL AND MECHANICAL TREATMENTS <ul><li>Velocity-assisted corrosion changes with thermo mechanical treatments </li></ul><ul><li>Increasing cold work decreases the corrosion rate </li></ul><ul><li>Q & T steel shows the lowest corrosion rate </li></ul>
  20. 20. TABLE 4. EFFECT OF THERMOMECHANICAL TREARMENTS ON CORROSION 617 42 Q & T 671 70 50% C. R. 793 48 30 % C. R. 832 47 10 % C. R. 932 85 Hot rolled 5054 28 Annealed Dynamic 1. 36 m/s 20 hrs. Static 24 hrs Corrosion rate, mdd in 3. 5 % NaCl solution Thermo mechanical Treatment
  21. 21. EFFECT OF HARDNESS <ul><li>Velocity-assisted corrosion decreases with increasing hardness of the steel. </li></ul><ul><li>This dependence attributed to impingement attack and/or cavitation damage. </li></ul>
  22. 22. CONCLUSIONS <ul><li>API X-52 steel undergoes erosion-corrosion in flowing 3. 5 % NaCl solution. </li></ul><ul><li>Increasing velocity increases the corrosion rate, the increase dependent on the condition of steel. </li></ul><ul><li>The dynamic corrosion of the steel decreases with increasing hardness. </li></ul>
  23. 23. LIST OF PUBLICATIONS <ul><li>Amarnath, M. M. Singh and T. K. G. Namboodhiri, Corrosion of API X-52 grade line pipe steel in sodium chloride media, Trans. SAEST, 35 (2000), 85-90 </li></ul><ul><li>Amarnath, T. K. G. Namboodhiri and S. N. Upadhyay, Flow Assisted Corrosion of API X-52 Steel in 3. 5% NaCl Solution, The Canadian Journal of Chemical Engineering, 80 (2002) (6), 456-464 </li></ul><ul><li>Amarnath and T. K. G. Namboodhiri, Effect of cold rolling on the hydrogen-induced delayed failure of API X-52 line-pipe steel, Trans. Indian Inst. Metals, 55 (2002), 25-30 </li></ul><ul><li>G. Ananta Nagu, Amarnath and T. K. G. Namboodhiri, Effect of heat treatments on the hydrogen embrittlement susceptibility of API X-65 grade line-pipe steel, Bull. Mater. Sci. ,26 (2003)435-439 </li></ul><ul><li>Amarnath, S. N. Upadhyay and T. K. G. Namboodhiri, Effect of thermal and mechanical treatments on corrosion of API X-52 grade line-pipe steel in flowing 3. 5 % NaCl solution, Indian J. Chem. Technol. , 10 (2003) 611-614 </li></ul>

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