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. • Introduction
• Causes of CUI and Mitigation of CUI
• CUI Coating Solutions
• Coating Testing
Agenda
Protective Coatings
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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.

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
Courtesy: NACE International IMPACT Study, 2016
G2MT Laboratories 2014
Pierre Crevolin, NACE Western Regional Conference 2005

4. 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)
Corrosion Under Insulation (CUI) – Costs Billions

5. Corrosion Related Accidents

6. Corrosion Under Insulation

7. 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 SP0198 - 2010 & EFC 55
Carbon Steel - 4C to 175C
Stainless Steel 50C to 175C
Overview of CUI

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 212o
F 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

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

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
SteelWater
Corrosion

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

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

15. Metallic, Organic and Inorganic Solutions to CUI?

16. • 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
CUI Solutions - Thermal Spray Aluminum

17. Organic – Epoxy
Organic - Phenolic/ Novolac Epoxy
Inorganic –
Conventional Thin Film Silicones, TSA
Inorganic -
Inorganic copolymer, TMIC
Inorganic - Zinc Silicates
650C
Technology
CUI Solutions – Transcendence Road
125C
220C
400C
600C
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

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

19. NACE SP 0198-2010SP0 198-2010 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, 100-200
(4-8)
Epoxy novolac or silicone hybrid,
100-200 (4-8)
CS-5
-45° to 595°C
(-50 to 1100°F)
NACE No. 1 /
SSPC-SP 515
50-100 (2-4)
TSA, 250-375 (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)
NACE No. 2 /
SSPC-SP 10
40-65 (1.5-2.5)
Inorganic coplymer or
coatings with an inert
multipolymeric matrix,
100-150 (4-6)
Inorganic coplymer or coatings with an inert
multipolymeric matrix, 100-150 (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: Epoxy Phenolic
High Temperature
Silicone Acrylic
Heat Resistant Cold
Spray Aluminum
High Temperature
Silicone
IMMP
Temperature
Ranges:
Ambient up to
392F; intermittent
surges up to 446F
Ambient up to
500F
-321F up to 1200F
Ambient up to
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 2-coats x 4 mils DFT
1-coat x 1.6 mils DFT
over IOZ 500F
over OZ 300F
1-coat x 8 mils DFT
2-coats x 1-1.5 mils
DFT
over IOZ
1-coat x 8 mils DFT
Under
Insulation:
Yes No Yes No Yes
Substrate:
Carbon Carbon Carbon Carbon Carbon
Stainless Stainless Stainless Stainless Stainless
IMMP = Inert Multipolymeric Matrix Paint
TMIC = Titanium Modified Inorganic Copolymer

21. 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
Densely Cross-linked
Epoxy Phenolic
Epoxy
Phenolic
Polyamine
+
Crosslink
Epoxy Phenolic and Novolacs
(CS-4; - 45C to 205C, -50F to 400F)

22. • 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
Barrier Protection Playing Field
(CS-6; - 45C to 650C, - 50F to 1200F) Examples:

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

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

25. 25Marine & Protective Coatings
CUI Coatings - More Balancing
Damage own to metal
Harder Coating
“Bruising” effect only
Softer Coating

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

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

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

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

30. 70C-100C 100C-165C 165C-215C 215C-300C 300C-450C 450C-560C
Coatings on Carbon Steel up to 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
Method B 5% NaCl solution
Temperature Control Ambient to
250C

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. Thank You - Questions?
www.akzonobel.com/protective
Vijay Datta, MS
vijay.datta@akzonobel.com
Dr. Mike O'Donoghue
mike.odonoghue@akzonobel.com