1. From Trauma to Transcendence: CUI and Coatings of Choice
Dr. Mike O’Donoghue – AkzoNobel
Vijay Datta, MS – AkzoNobel
SSPC Webinar, October 25th , 2016

2. Agenda Introduction Causes of CUI and Mitigation of CUI
CUI Coating Solutions
Coating Testing
Unless otherwise agreed in writing by AkzoNobel, all products supplied together with all technical service, information, advice and recommendations given are subject to our standard terms and conditions of sale which are available on request. Any information given here is for guidance only and is provided without any representation or warranty of any kind, express or otherwise. Further, AkzoNobel accepts no control or liability for the appropriateness of any product or the surface, structure or design to which our products are applied or the application process itself. You should seek independent expert advice as to the appropriateness of a particular design or structure for use of our products. We also strongly recommend that independent testing and/or assessment is carried out prior to the application of any product to determine suitability for use.
Protective Coatings

3. Corrosion Cost Comparison
Annual Global Cost of Corrosion: > US$ 2.5 Trillion
(3.4% of a country’s GDP)
Annual Cost of US Natural Disasters : > $19 Billion
Corrosion costs the US Economy
> 50 times
as much as all the natural disasters
Vijay – read and cite Pierre Crevolin (what was G2 MT Vijay?)
Vijay – Impact Study States “ By using currently available corrosion control practices, it is commonly estimated that savings of between 15 and 35% could be realized….
Courtesy: NACE International IMPACT Study, 2016
G2MT Laboratories 2014
Pierre Crevolin, NACE Western Regional Conference 2005

4. Corrosion Under Insulation (CUI) – Costs Billions
Corrosion rates of carbon steel can be significant if operating at high temperatures and subject to temperature cycling, particularly when thermally insulated
“… approximately 35% of incidences of corrosion failures, or near failures were caused as a result of corrosion under insulation …”
(This statement follows a 2 year survey of plant failures at a major US petrochemical complex)

5. Corrosion Related Accidents
Motiva Delaware City started when sparks from welding on a catwalk fell onto, and then into, a severely corroded sulfuric acid tank, that then ignited and exploded.

6. Corrosion Under Insulation

7. Overview of CUI
Corrosion of steel under thermal insulation due to the presence of moisture, oxygen, and other corrodents
Known since 1950’s
High interest since 1983
NACE SP & EFC 55
Carbon Steel C to 175C
Stainless Steel 50C to 175C

8. CUI Corrosion under ‘wet’ thermal insulation - aggressive
CUI is up to 20x faster than atmospheric corrosion (1.5 – 3.0 mm/year)
Insulated high temperature steelwork requires protection against CUI which is a threat during construction, shutdown and intermittent use of equipment

9. Why is there is a problem?
No insulation is 100% waterproof
The corrosion rate under wet insulation can be up to 20 times greater
than the rate at ambient operating conditions
Corrosion is hidden
Nothing runs above 212oF forever
Equipment temperatures cycle
Inspection can be limited and costly
Reluctance to shut down unit
Budgetary concerns

10. Implications of CUI Critical Steel Temperature Ranges for corrosion:
C-Steel 25F → 302F (Greatest Risk of Corrosion)
S-Steel 122F→ 302F (Greatest Risk of E.S.C.C. )
The highest corrosion rates are normally experienced in operational conditions
between 140F to 250F
Moisture ingress into broken or compromised insulation can occur from
32F to 302F
E.S.C.C. = External Stress Corrosion Cracking
Stress corrosion cracking (SCC) is the growth of cracks in a corrosive environment. It can lead to unexpected sudden failure of normally ductile metals subjected to a tensile stress, especially at elevated temperature in the case of metals. SCC is highly chemically specific in that certain alloys are likely to undergo SCC only when exposed to a small number of chemical environments. The chemical environment that causes SCC for a given alloy is often one which is only mildly corrosive to the metal otherwise.

11. Thermal Cycling – The vehicle for CUI
Moisture movement
Insulation
Coating
HEATING
COOLING
Steel
Coating must provide excellent corrosion protection to insulated steelwork which experiences thermal cycling conditions

12. Corrosion at Elevated Temperatures
For corrosion to occur three key elements MUST be present
Water is not present in equipment where continuous operating temperatures above 248F exist
However, during shut down or cyclic temperature operations, rapid cooling can lead to condensation, & subsequent corrosion problems
Repeated cycling increases both corrosion rates, and potential for failure of coating systems
Air
Steel
Water
Corrosion

13. CUI Dynamics C U I Moisture Under Insulation Project Soluble Chlorides
Budget
Soluble Chlorides
C U I
Inspection
Cyclic
Temperatures
Maintenance
Requirements

14. CUI Coating Solutions - Balancing…
Anticorrosive
Properties
Thermal Resistance
(Cartoon Figs Courtesy Hexion)

15. Metallic, Organic and Inorganic Solutions to CUI?
Mike

16. CUI Solutions - Thermal Spray Aluminum
Flame spray, arc spray, plasma spray techniques
Aluminum Spray Alloy 1100 or 1350
SSPC-SP5/NACE 1/Sa3 (3-4 mils)
Temp Resistance to ca 595C
Life cycle costs are low
Process slow, installation costs are relatively high vs coating spray application, DFT issues, needs to form oxides
Galvanic protection – sacrificial system
Susceptible to corrosion by wet salts above 80C
Porosity
Seal coat or no-sealer coat?
Wire
Compressed Atomising Air
Oxygen Fuel Gas Mixture
Coating
Spray stream of molten atomised particles
Substrate
Nozzle
Air Cap
A long and accomplished history of success
Offshore platforms and bridges
For CUI – the jury is out – TSA can deteriorate under wet insulation
Sacrificial system
International Standards for application and composition
High degree of Surface prep
Porous, some interconnectivity of voids, open structure
We studied sealing: porosity reduced, see Ole Knudsen

17. CUI Solutions – Transcendence Road
Temperature
Higher bond strengths of
Inorganic Si-O bond (452 KJ mol-1)
vs Organic C-C bond (350 KJ mol-1 )
confers thermal stability
Inorganic -
Inorganic copolymer, TMIC
650C
Inorganic –
Conventional Thin Film Silicones, TSA
600C
400C
Inorganic - Zinc Silicates
vijay
Organic - Phenolic/ Novolac Epoxy
220C
Organic – Epoxy
125C
Technology
Protective Coatings

18. The Zinc Silicate Question (photo courtesy Peter Bock)

19. NACE SP
SP Typical Protective Coating Systems for Carbon Steels Under Thermal
Insulation and Fireproofing – Courtesy Art MacKinnon, PPG Hi-Temp Coatings
System Number
Temperature Range (A)(B)
Surface Preparation
Surface Profile, µm (mil) (c)
Prime Coat,
µm (mil) (D)
Finish Coat, µm (mil) (D)
CS-1, CS-2, CS-3
 Epoxy, Fusion Bonded Epoxy, Epoxy Phenolic minus 110° to 302°F [minus 45° to 150°C]
CS-4
-45° to 205°C (-50 to 400°F)
NACE No. 2 / SSPC-SP 10
50-75 (2-3)
Epoxy novolac or silicone hybrid, (4-8)
Epoxy novolac or silicone hybrid,
(4-8)
CS-5
-45° to 595°C (-50 to 1100°F)
NACE No. 1 / SSPC-SP 515
(2-4)
TSA, (10-15) with minimum of 99% aluminum
Optional: Sealer with either a thinned epoxy-based or silicone coating (depending on maximum service temperature) at approximately 40 (1.5) thickness
CS-6
-45° to 650°C (-50 to 1200°F)
40-65 ( )
Inorganic coplymer or coatings with an inert multipolymeric matrix, (4-6)
CS-7
Petroleum wax primer; ambient to 140°F [60°C]
CS-8
Shop primers and topcoats for inorganic zinc (IOZ)  minus 110° to 750°F [minus 45° to 400°C]
Novolac, phenolic, inorganic copolymer and inert polymeric matrix

20. Coatings for CUI Mitigation
Epoxy Phenolic
Silicone Acrylic
TMIC
Silicone
IMMP
Binder:
High Temperature Silicone Acrylic
Heat Resistant Cold Spray Aluminum
High Temperature Silicone
Temperature Ranges:
Ambient up to
392F; intermittent surges up to 446F
500F
-321F up to 1200F
1004F
-321F up to 1202F
Typical Systems:
2-coats x 4-6 mils DFT
2-coats x 1.6 mils DFT
2-coats x 4 mils DFT
3-coats x 1 mil DFT
1-coat x 1.6 mils DFT
over IOZ 500F
over OZ 300F
1-coat x 8 mils DFT
2-coats x mils DFT
over IOZ
Under Insulation:
Yes No
Substrate:
Carbon
Stainless
302F = 150C
392F = 200C
446F = 230C
500F = 260C
300F = 150C
-321F = C
752F = 400C
-265F = -165C
1050F = C
1004F = 540C
1202F = 650C
IMMP = Inert Multipolymeric Matrix Paint
TMIC = Titanium Modified Inorganic Copolymer

21. Epoxy Phenolic and Novolacs (CS-4; - 45C to 205C, -50F to 400F)
Barrier Protection - Epoxy Phenolic coatings perform well in high temperature aggressive environments because of their very densely cross linked nature
Epoxy
Polyamine +
Crosslink
Typical Cross-linked Epoxy
Epoxy
Phenolic
Polyamine +
Crosslink
VJ explains
Densely Cross-linked Epoxy Phenolic

22. Barrier Protection Playing Field (CS-6; - 45C to 650C, - 50F to 1200F) Examples:
Carboline Thermaline 4001
Dampney Thurmalox 225HD
Hempel Versiline 56990
International Interbond UPC 1202
Jotun Jotatemp 650
PPG Hi-Temp 1027
Sherwin Williams Heat-Flex Hi –Temp 1200

23. MIO Pigmented IMMP for CUI Mitigation
SEM Image after 4000C
200X Magnification
MIO Platelets
Barrier Protection

24. Aluminum Flake Pigmented TMIC for CUI Mitigation
SEM Image after 4000C
1000X Magnification
Interlacing aluminum platelets, intact
Barrier Protection

25. CUI Coatings - More Balancing
Damage own to metal
Harder Coating
“Bruising” effect only
Softer Coating
Vijay explains
This is TMIC – Titanium Modified Inorganic Copolymer
Q. VJ to M: How does real life experience of this technology compare with the laboratory tests, is there any correlation? You have done lots of independent lab testing on this technology, tell us about that?
Marine & Protective Coatings

26. International Paints Cyclic Pipe Tests Courtesy O’Donoghue and Datta, International Paint
CCCPT
CUI Cyclic Corrosion Pipe Test

27. Courtesy O’Donoghue and Datta, International Paint`
CUI Cyclic Pipe Tests
Courtesy O’Donoghue and Datta, International Paint`
100C
Diameter = 6 cm
Length = 60 cm
1 litre 1% NaCl twice/day
Temperature °C
Time
600C
8 hours
Heated to
600C
Naturally
cooled
16 hours
Repeated
x 30
600C
cyclic temperatures to mimic end user processes

28. Monitoring / Verifying the Coating Temperature
CCCPT procedure run with temperature probes to measure temperatures across the pipe

29. TSA and IMMP & TMIC Coatings on Carbon Steel
VJ explains
IMMP
TSA

30. Coatings on Carbon Steel up to 560C
70C-100C
100C-165C
165C-215C
215C-300C
300C-450C
450C-560C
IMMP
TMIC

31. PPG CUI Chamber Test (2008-Present) Courtesy Dik Betzig PPG Hi-Temp Coatings
Testing method approved:
Shell Oil 2008, Aramco 2010
Method B 350F (177C) 5% NaCl
Temperature Control Ambient to 250C
Method B 5% NaCl solution

32. CUI Chamber Test Cell Courtesy Dik Betzig PPG Hi-Temp Coatings
Before Test
After 6 Weeks Front View
After 6 Weeks Bottom View

33. Track Record Cyclic Service Conditions: 260C to 40C

34. Case History France

35. Case History France

36. Case History Texas

37. Case History Texas

38. Publications
“When Undercover Agents are Tested to the Limit: Coatings in Action (CIA) and Corrosion Under Insulation”
JPCL, May 2014 SSPC Presidential Lecture Series Award in 2013
“When Undercover Agents Can’t Stand the Heat: Coatings in Action (CIA) and the Netherworld of Corrosion Under Insulation”
JPCL, February 2012 Outstanding Publication of the Year Award in 2013
“From Trauma to Transcendence: Corrosion Under Insulation”
NACE, Northern Area Western Conference, 2010

39. Vijay Datta, MS vijay.datta@akzonobel.com Dr. Mike O'Donoghue
Thank You - Questions?
Vijay Datta, MS 
Dr. Mike O'Donoghue