Using Chemical Vapor Deposition Processes to Enhance the

Using Chemical Vapor Deposition Processes to Enhance the Corrosion Performance of Steel Substrates Silco. Tek Corporation Gary Barone

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

APPLICATION AREAS • Silco. Nert™: Inertness • Silcolloy™: Anti-Corrosion • Silco. Klean™: Anti-Coking • Silco. Guard™: Ultra-High MARKET AREAS Analytical Pharmaceutical Environmental Petrochemical Chemical Process Semiconductor/Research Vacuum Automotive

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/cm 3 o Melting point: 1410 C Max operating temp. • 600 o. C to 1000 o. C: Silcolloy; Silco. Nert 1000; Silco. Guard • 450 o. C Silco. Nert 2000 • 1200 A to 5 um thickness, minimal smoothing of surface

Coating Cross Section 316 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 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

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 B 117 Corrosion – Stress corrosion cracking (Mg. Cl 2; ASTM G 36)

ASTM G 48 B Data: Pitting and Crevice Corrosion • ASTM G 48 method B; Pitting and Crevice Corrosion – 6% Ferric Chloride solution – 72 hrs, 20ºC – 316 L Stainless samples w/Gasket wrap Sample Initi Fina We Weig al l i ht Wei g Lo g g h ss h h t (g/m 2 t t Lo ) ( ( s g g s ) ) ( Corrosion g

ASTM G 48 B (cont. ) • Bare 316 L Stainless Steel coupon showing severe crevice corrosion Corrosion

ASTM G 48 B (cont. ) • Corrosion resistant treated sample showing no crevice corrosion and slight pitting corrosion Corrosion

ASTM G 61 Data: Cyclic Polarization • ASTM G-61; Cyclic Polarization Electrochemical Corrosion Testing – Acid, neutral, basic aqueous solutions with varying Cl- ion concentrations (100, 3000, 5000 ppm) – EG&G Versa. Stat System, 23ºC – 316 L vs. Silcolloy™ on 316 L & 304 L -CR vs 316 L Raw: 50 x improvement Neutral solution; 3000 ppm Cl- Ec = corrosion potential Ic = current density at Ec Eb = pitting potential CR = corrosion rate Sample Ec, m. V Ic, u. A/cm^2 Eb, m. V 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 Corrosion

ASTM B 117 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. Corrosion

ASTM B 117 Data (cont. ) • Silcolloy™ treated samples showed no signs of bleeding, rusting, or pitting corrosion Corrosion

ASTM B 117 Data (cont. ) • The non-treated samples showed some light surface rusting, but no signs of pitting corrosion. Corrosion

ASTM D 4585 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 Corrosion

ASTM D 4585 (cont. ) • Silcolloy™ treated samples showed no signs of bleeding, rusting, or pitting corrosion 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: Corrosion – High temperature stability up to 1000 c

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 Corrosion 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 ?