Using Chemical Vapor Deposition Processes to Enhance the Corrosion Performance of Steel Substrates...
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Transcript of Using Chemical Vapor Deposition Processes to Enhance the Corrosion Performance of Steel Substrates...
Using Chemical Vapor Deposition Processes to Enhance the Corrosion Performance of Steel Substrates
SilcoTek CorporationGary Barone
Topics
• About Us• Products and Applications• Product Performance• Conclusion/Future Product Development
APPLICATION AREAS• SilcoNert™: Inertness
• Silcolloy™:Anti-Corrosion
• SilcoKlean™: Anti-Coking
• SilcoGuard™: Ultra-High Vacuum
MARKET AREAS
AnalyticalPharmaceuticalEnvironmental
PetrochemicalChemicalProcess
Automotive
Semiconductor/Research
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
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
Coating Cross Section
316 SS316 SS
Auger Depth Profile
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
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
Substrates Which Coat Well
• 300 and 400 grade stainless steel
• High carbon steel
• Titanium
• Ceramics
• Borosilicate glass
• Inconel®
• Hastelloy®
Substrates with Issues
• Nickel / Nickel plating• Aluminum*• Monel®• Copper• Brass• Gold and Silver plated components • Chrome Plated components• Magnesium• Elastomers
*heat-dependent
Corrosion Resistance of Coatings
Silcolloy™Corrosion 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.
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)
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 InitialWeight (g)
FinalWeight (g)
WeightLoss (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
ASTM G48 B (cont.)
• Bare 316L Stainless Steel coupon showing severe crevice corrosion
ASTM G48 B (cont.)
• Corrosion resistant treated sample showing no crevice corrosion and slight pitting corrosion
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)– EG&G VersaStat System, 23ºC– 316L vs. Silcolloy™ on 316L & 304L
Neutral solution;3000ppm Cl-
Sample Ec, mV Ic, uA/cm^2 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
Ec = corrosion potentialIc = current density at EcEb = pitting potentialCR = corrosion rate
-CR vs 316L Raw: 50x improvement
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.
ASTM B117 Data (cont.)
• Silcolloy™ treated samples showed no signs of bleeding, rusting, or pitting corrosion
ASTM B117 Data (cont.)
• The non-treated samples showed some light surface rusting, but no signs of pitting corrosion.
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
ASTM D4585 (cont.)
• Silcolloy™ treated samples showed no signs of bleeding, rusting, or pitting corrosion
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
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)
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.
QUESTIONS ?