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Similar a Improving Surface Characterics In Nickle Alloys Rev May 08 Inc Passivation
Similar a Improving Surface Characterics In Nickle Alloys Rev May 08 Inc Passivation (20)
Improving Surface Characterics In Nickle Alloys Rev May 08 Inc Passivation
- 1. Improving Surface Characteristics in Nickel Alloys through Electropolishing Ken Kimbrel This presentation is the intellectual property of UltraClean Electropolish, Inc. Do not reproduce in part or in whole without prior written authorization of UltraClean Electropolish, Inc. 03-01-06
- 2. Electropolishing Why Bother? Electropolishing Why Bother?
- 3. Do You Think This Surface is Easier to Clean or….. 20Ra
- 4. Would This Surface Be Better? 20Ra
- 5. 10 Ra – 2B Sheet Metal 1000 X 2B Sheet Metal 10Ra, 1500X How About This vs. …..
- 6. 5Ra – 2B Electropolish 2B – Electropolished 7Ra, 1500X This?
- 12. Electropolishing; How it Works
- 13. Electropolishing; How it Works
- 15. Electropolishing; How it Works
- 16. Electropolishing – How it Works The process can also be performed “on site” or “in situ” by firms that specialize in this service. This allows equipment purchased without the finish, or equipment originally electropolished and damaged, to be repaired or completely electropolished where it sits. Electropolishing; How it Works
- 17. Electropolishing; How it Works 120 Ra MILL FINISH - Hot Rolled Annealed 316 Plate Material
- 18. Electropolishing; How it Works 35 Ra ELECTROPOLISHED - Hot Rolled Annealed 316 Plate Material
- 19. Electropolishing; How it Works As Electropolishing Exposure Increases Microscopic Smoothing Continues Until Optimum Improvement is Achieved
- 21. Electropolishing; How it Works When the process is allowed to continue for an adequate amount of time the surface becomes microscopically smooth and virtually featureless As the anodic film becomes uniform in thickness the benefits of electropolishing have been accomplished and material will continue to be removed uniformly until the process is stopped
- 24. 2B Stainless Sheet Metal SEM 1500X – 304 Stainless Steel Note the cross section in the following slide to see illustration of surface roughness
- 25. 2B Stainless Sheet Metal White Light Interfermetric Surface Analysis Observe this cross section Ra 7.4uin
- 26. #4 Stainless Sheet Metal SEM 1500X – 180 grit 304 Stainless Steel
- 27. #4 Stainless Sheet Metal Ra 11.5uin
- 28. Electropolished Stainless Coupon SEM 1500X - 304 Stainless Steel
- 29. Electropolished Stainless Sheet Metal Compare this to previous slides Ra 2.3uin
- 32. Electropolishing; Why it Works Electropolishing allows for the removal of any distorted or “damaged” material layer that will be present following grinding, sanding, or machining. #4, 3A, 180 grit 304 sheet Electropolished
- 35. Damaged Layer – “Bielby Layer” 180 grit sanded surface 180 Grit -Electropolished .0003”
- 36. Damaged Layer – “Bielby Layer” 80 grit sanded mill plate – damage .0006”
- 38. Bacterial Control NO ELECTROPOLISH ELECTROPOLISHED The Cold Worked, Damaged, or Beibly layer offers significant site for bacterial adhesion and bio-film formation. Bacterial bio-films can contribute to corrosion as they can breakdown the passive film underlying the formations. If the bio-film is them successfully removed an “active site” (non-passivated) can allow corrosion to initiate via a galvanic effect.
- 39. “ Multiple imaging techniques demonstrate the manipulation of surface to reduce bacterial contamination and corrosion” J.W. Arnold, D.H. Booth, O. Suzuki, & G. W. Bailey – Journal Of Microscopy, Vol. 216, Pt 3 Dec. 2004 In this study the researchers exposed samples of 2B “mill finish” (control) and the same material electropolished. Four sets of disc were included in this study; A 2B “mill finish” B Electropolished C 2B followed by corrosive treatment D Electropolished followed by corrosive treatment Corrosive Treatment: “The disks were placed in 100ml purified water, autoclaved for 1h, brought to room temperature and water supplemented to 100ml…repeated 50 times and the process carried out twice per day”
- 40. “ Multiple imaging techniques demonstrate the manipulation of surface to reduce bacterial contamination and corrosion” J.W. Arnold, D.H. Booth, O. Suzuki, & G. W. Bailey – Journal Of Microscopy, Vol. 216, Pt 3 Dec. 2004
- 44. Material Applications & Benefits AL-6XN As Received 1000X
- 45. Material Applications & Benefits
- 46. Material Applications & Benefits AL-6XN Mechanical Polished 1000X
- 47. Material Applications & Benefits
- 48. Material Applications & Benefits AL6XN Electropolished 1000X
- 49. Material Applications & Benefits
- 56. “ In Situ” Vessel Remediation 4000 liter “in place” 316L SS Vessel Agitator Damage Sanded to 320 grit (10 Ra) Bottom Head – Scuffs & Rouge Sanded to 320 grit (10 Ra)
- 57. “ In Situ” Vessel Remediation 4000 liter “in place” 316L SS Vessel Agitator Damage – Sanded, Electropolished Bottom Head & Entire Vessel Electropolished
- 58. Vessel Remediation Wiper/Scrapper Damage, Never Electropolished Operator Damage, Scratches 200 Liter Portable Vessel – Never Electropolished
- 59. Vessel Remediation 200 Liter Portable Vessel 316L
- 61. Vessel Remediation Size (Liters) Description of work 5,790 Removed minor scratches and electropolished the entire interior surface 726 Removed minor scratches and electropolished the entire interior surface 6,828 Electropolished the entire interior surface 3,900 Electropolished the entire interior surface 200 Removed minor scratches and electropolished the entire interior surface 726 Removed minor scratches and electropolished the entire interior surface 9,250 Removed very deep pitting and electropolished the entire interior surface 22,000 Removed very deep pitting and electropolished the entire interior surface 30,800 Removed very deep pitting and electropolished the entire interior surface 20,000 Removed very deep pitting and electropolished the entire interior surface
- 63. Electropolishing Why Bother? Electropolishing Why Bother?
- 71. Weld Seam Analysis Before Passivation millimeters Article By: K. Balmer Heat Affected Zone
- 72. Weld Seam Analysis After Passivation millimeters Article by: K. Balmer Heat Affected Zone
- 74. Passivated and Non-Passivated Tube Sections - Salt Spray Test
- 75. Cleaning Processes Passivation Process Process Description Chemistry Conditions of Process Pros Cons Cleaning Processes Phosphate cleaners Blends of sodium phosphates (TSP,DSP,MSP) and surfactants 1 to 2 hours at 60 to 80 degrees C Removes light organic deposits Can leave phosphate surface contamination Alkaline cleaners Blends of non-phosphate detergents, buffers and surfactants 1 to 4 hours at 40 to 80 degrees C. Can be designed for specific organic contaminates Caustic cleaners Blends of sodium and potassium hydroxides and surfactants 1 to 2 hours at 60 to 80 degrees C Effective at removal of heavy organic contamination
- 76. Passivation Process Passivation Process Process Description Chemistry Conditions of Process Pros Cons Passivation Process Nitric acid 10 to 40% active nitric acid 30 to 90 minutes at ambient temperatures Proven method. ASTM recommended and can be run at ambient temps Generates hazardous waste Phosphoric acid 5 to 25% phosphoric acid 1 to 4 hours+ @ 40 to 80 degrees C Effective at removing iron oxides in addition to iron Phosphoric acid blends 5 to 25% citric acid + either citric or nitric acid at various concentrations 1 to 4 hours+ @ 40 to 80 degrees C Can be used at a variety of temperatures and conditions Citric acid 10% citric acid 2 to 4 hours at 40 to 80 degrees C Specific for iron removal. Takes longer to process than mineral acid systems Chelant systems 3 to 10% citric acid with various chelants, buffers, and surfactants 2 to 4 hours at 60 to 80 degrees C. Should be run at elevated temps. Takes longer to process than mineral acid systems
Notas del editor
- The standard or typical treatment includes the items listed, including: An initial DI water rinse; a derouging phase, if required; a cleaning or decontamination phase with detergents; a passivation phase; a sanitization or oxidation phase and final rinse to a conductivity endpoint. During the passivation phase, the amount of iron dissolved into the solution is measured. This is our means to verify passivation endpoint is met; All iron has been dissolved from the surface. The conductivity endpoint is verifying the final rinse to show that the effluent water quality matches the influent water quality; or water coming out the system is as clean as the water going in.
- Here is the reason passivation is required for newly fabricated or constructed systems. This is a series of Auger analyses that were performed across the weld area of a 316L tube sample. It shows that the area at and near the weld bead is very high in iron with almost no chromium at the surface, yet still in an oxidized condition. The heat effected zone appears on both sides of the weld, with relatively speaking, equal parts iron and chromium. However, this associates with a dark band that consists of chromium carbide precipitation and an equally susceptible area for corrosion. That is why you often see iron oxide rouge on the weld or in the heat effected zone from corrosion. Now, if you passivate this weld…..
- We can repair the damage due to welding with passivation and re-form the passive layer to form a 2 to 1 chromium to iron ratio protective film. You see that the weld area and the heat effected zone has been fixed. These areas are now as good as the standard tubing area ON THE SURFACE . One note : If you have weld damage below the three or four molecular levels, it will still show through, visibly; and you will likely, with some amount of corrosion, break through the protective passive layer and get to the damage zone below over time. The corrosion rate will be much higher than expected, even for the alloy, resulting in pitting corrosion and possible tube failure.