Using Chemical Vapor Deposition Processes to Enhance the Corrosion Performance of Steel Substrates

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Using Chemical Vapor Deposition Processes to
Enhance the Corrosion Performance of Steel
Substrates

• SilcoTek Corporation
• Gary Barone

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Topics

• About Us
• Products and Applications
• Product Performance
• Conclusion/Future Product Development

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• MARKET AREAS

• APPLICATION AREAS
• SilcoNert Inertness
• SilcolloyAnti-Corrosion
• SilcoKlean Anti-Coking
• SilcoGuard Ultra-High Vacuum

Analytical Pharmaceutical Environmental
Petrochemical Chemical Process
Semiconductor/Research
Automotive
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Basic Manufacturing Process

• Receive items
• Document digital, customer contact
• Clean
• Standard caustic ultrasonic bath, 2 systems
• Custom solvation via other means
• Chemical Vapor Deposition (CVD) Process
• Vacuum
• 400ºC
• silicon-based deposition
• Clean
• Document digital, customer contact
• Pack, ship

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Product Characterization

• Amorphous silicon CVD coating
• Density 2.33 g/cm3
• Melting point 1410oC
• Max operating temp.
• 600oC to 1000oC Silcolloy SilcoNert 1000
  SilcoGuard
• 450oC SilcoNert 2000
• 1200A to 5um thickness, minimal smoothing of
  surface

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Coating Cross Section
316 SS
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Auger Depth Profile
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Coating Capabilities Substrates

• Tubing
• 0.004 to 0.5 ID
• 2000 ft. continuous lengths
• Complex geometry parts (inside and out)
• Fittings, valves, frits
• Block manifolds, sample vessels
• custom parts

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Sizes of reaction chambers

• Standard vessels
• 12 diameter cylinder w/ 56 height
• 6 diameter cylinder w/ 72 height
• 10 diameter cylinder w/ 18 height
• 21 diameter cylinder w/ 42 height
• Large processing oven
• 27 diameter x 26 deep
• Walk-in Oven
• 4 feet by 4 feet by 5 feet
• 6 feet by 4 feet by 5 feet

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Substrates Which Coat Well

• 300 and 400 grade stainless steel
• High carbon steel
• Titanium
• Ceramics
• Borosilicate glass
• Inconel
• Hastelloy

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Substrates with Issues

• Nickel / Nickel plating
• Aluminum
• Monel
• Copper
• Brass
• Gold and Silver plated components
• Chrome Plated components
• Magnesium
• Elastomers
• heat-dependent

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Corrosion Resistance of Coatings
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SilcolloyCorrosion Resistance

• Stainless steel surfaces susceptible to attack
  from in chlorinated environments and acidic
  exhaust environments.
• Corrosion resistant deposition is insoluble in
  hydrochloric acid and unaffected in salt water
  environments.

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Corrosion Resist studies

• External Evaluation
• Certified corrosion
• engineers (Matco)
• Spectroscopic
• analysis
• Mechanical testing
• Electrochemical
• Cyclic Polarization in neutral, acidic, alkaline
• Atmospheric corrosion
• ASTM moisture condensation
• Salt spray ASTM B117
• Stress corrosion cracking (MgCl2 ASTM G36)

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ASTM G48 B Data Pitting and Crevice Corrosion

• ASTM G48 method B Pitting and Crevice Corrosion
• 6 Ferric Chloride solution
• 72hrs, 20ºC
• 316L Stainless samples w/Gasket wrap

Sample Initial Weight (g) Final Weight (g) Weight Loss (g) Weight Loss (g/m2)
Silcolloy Sample 17 10.4105 10.3710 0.0395 19
Silcolloy Sample 28 10.1256 10.0743 0.0513 25
Silcolloy Sample 47 10.1263 10.0742 0.0521 25
Bare Sample 27 10.0444 9.5655 0.4789 231
Bare Sample 34 10.1265 9.6923 0.4342 209
Bare Sample 37 10.1007 9.6276 0.4731 228
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ASTM G48 B (cont.)

• Bare 316L Stainless Steel coupon showing severe
  crevice corrosion

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ASTM G48 B (cont.)

• Corrosion resistant treated sample showing no
  crevice corrosion and slight pitting corrosion

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ASTM G61 Data Cyclic Polarization

• ASTM G-61 Cyclic Polarization Electrochemical
  Corrosion Testing
• Acid, neutral, basic aqueous solutions with
  varying Cl- ion concentrations (100, 3000,
  5000ppm)
• EGG VersaStat System, 23ºC
• 316L vs. Silcolloy on 316L 304L

-CR vs 316L Raw 50x improvement
Ec corrosion potential Ic current density at
Ec Eb pitting potential CR corrosion rate
Neutral solution 3000ppm Cl- Neutral solution 3000ppm Cl-
Sample Ec, mV Ic, uA/cm2 Eb, mV CR, mpy
316 L -418 0.096 370 0.04
Silcolloy 316 L  -533 0.002 1460 0.0009
304 L -435 0.145 361 0.06
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ASTM B117 Data Salt Spray

• ASTM B 117 Practice for Operating Salt Spray
  (Fog) Apparatus.
• 4000 hour exposure
• 100 degree Fahrenheit
• 3.5 by weight sodium chloride
• Reproduces exposure to marine environments.

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ASTM B117 Data (cont.)

• Silcolloy treated samples showed no signs of
  bleeding, rusting, or pitting corrosion

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ASTM B117 Data (cont.)

• The non-treated samples showed some light surface
  rusting, but no signs of pitting corrosion.

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ASTM D4585 Data Condensing Humidity

• ASTM D 4585, Practice for Testing the Water
  Resistance of Coatings Using Controlled
  Condensation.
• 1000 hour study
• 100 degrees Fahrenheit
• Distilled water
• Reproduces exposure to atmospheric conditions

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ASTM D4585 (cont.)

• Silcolloy treated samples showed no signs of
  bleeding, rusting, or pitting corrosion

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Silcolloy Advantages

• Longer Life
• Extend lifetimes of equipment exposed to
  corrosive environments and/or process streams
• Protection
• Protection of high value equipment in corrosive
  environments
• Inert
• Provide enhanced corrosion resistance to
  analytical equipment while maintaining inert
  sample pathway
• High Temperature
• High temperature stability up to 1000c

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Silcolloy Applications

• Manufacturing/Chemical
• Process streams containing HCl
• Environmental
• Continuous Emissions Monitoring exposed to stack
  gases from coal fired plants and incinerators
• Automotive
• Equipment used in Automotive Exhaust testing and
  catalytic converter studies
• Diesel EGR Turbo systems
• Marine
• Some preliminary evaluation of coating in marine
  environments (offshore platforms)

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Conclusions/Future

• Continual process improvement and new product
  development for coatings
• Improving the hardness of coatings
• Improved corrosion resistant coatings
• Hydrophobic surfaces for moisture sensitive
  applications
• Protection of high nickel alloys such as
  Hastelloy and Inconel
• Hydrogen embrittlement resistance.

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QUESTIONS ?