1. Plenary Lecture: Corrosion Standards- Who Needs Them?
Sheldon W. Dean, Jr.
Dean Corrosion Technology, Inc
Corrosion 2010, San Antonio, TX
NACE International

2. What is a Standard?
Document that provides specific procedures or set of requirements for a commercial product or process that attains a consensus of knowledgeable people.
Compliance with standards is voluntary unless mandated by law.

3. International Society of Testing Materials- 1880’s.
History of Standards
International Society of Testing Materials- 1880’s.
ASTM founded ~1898.
NACE founded 1948.
ISO ~1960.

4. History of Corrosion Standards
• ASTM- 1904
- Steel vs. wrought iron in atmosphere
• ASTM-1939
- Salt Spray Test, B117
• NACE- Cathodic protection issues

5. History of Corrosion Standards, Continued
ASTM Reorganization Created Committee G-1 on Corrosion of Metals
NACE ~1960s Created Technical Practices Committee
ISO 1978 Created TC156 on Corrosion of Metals
11 Working Groups

6. 3 Examples of Standards ASTM G 5 Potentiodynamic Polarization
NACE SP0294 Sulfuric Acid Storage Tanks
ASTM G186/G188 Leak Detection Fluids

7. Potentiodynamic Polarization
Corrosion is electrochemical
Potentiostats became available (1960s)
Passive-active behavior of stainless steels revealed with potentiostat
Issues with reliability and reproducibility

8. ASTM G5 Reference Method 1969
430 stainless steel in 1.0 N H2SO4
Single lot of stainless steel
Carefully designed procedure
10 mV per min from Ecorr
Many participants
Reproducibility range shown

10. ASTM G 5 Potentiodynamic Composite

11. ASTM G 5 Crevice Effect

12. ASTM G 5 Standard Reference Method
First reference method
Results demonstrated reproducibility
Method widely used to qualify labs
Basis of many potentiodynamic studies
Method upgraded and improved several times

13. Who Needs ASTM G5? New researchers learning electrochemical methods
Technicians learning electrochemical techniques
Lab managers overseeing labs using electrochemical methods
Technical reviewers judging laboratory qualification to run electrochemical methods

14. Sulfuric Acid Storage Tanks
Sulfuric acid widely used chemical
Common grades: 93%, 96%, 98 to 99%
Carbon steel is tank material of construction
Corrosion rate low and manageable
Catastrophic failures have occurred
Other problems occur

15. Storage Tank Design API 650 is the basis for flat bottom tanks
API 650 is not adequate for sulfuric acid
Many problems have occurred with this design
Modifications are required for success
A design standard was needed

18. Problems with Concentrated Sulfuric Acid
Velocity accelerated corrosion of steel
Corrosion rate increases catastrophically when acid is diluted
Hydrogen corrosion product caused problems
Increased temperature increases corrosion rate

19. 163C
325F
107C
225F
52C
125F
24C
75F

20. Issues with C Steel Tanks
Corrosion allowance
Nozzle problems
Inlet/outlet design
Hydrogen grooving
Inspection frequency

21. NACE SP 0294 Original RP in 1994 Revision in 2006
Covered vertical and horizontal designs
RP 0205 covered spent alkalation acid
Fatal accident occurred earlier

23. Who Needs SP 0294? Sulfuric acid producers Sulfuric acid users
Tank inspectors
Plant maintenance engineers
Plant engineers
Consultants and contractors

24. Failures in High Pressure Gas Systems
Cylinder valve/pressure regulator connections
Cracking failures
Brass components, CDA 360
Older systems

25. Failure Analyses Intergranular cracks found Multiple branched cracks
Strain hardened alloy structure
External corrosion products
Bluish color noted
Mottled appearance

26. Probable Cause Stress corrosion cracking Ammonia or amines likely
Source- leak detection fluid (LDF)
Ammonia used to adjust pH of LDF
Brass strained through repeated tightening of components

27. Need: To Qualify LDFs Old MIL Spec not relevant
Non corrosive = <100mpy
Test to detect ammonia difficult
How much NH3 is needed to reject?
Method should simulate service
Performance test

28. Path Forward Find an SCC test for LDFs
Find a susceptible brass specimen
Test to verify susceptibility
Design atmospheric exposure program
Need to qualify atmosphere
Ammonia fumes are common in labs
May cause unrelated failures

29. Result: ASTM G 186 C-ring specimen of UNS C27200
Hard drawn temper, H80
0.65% strain
5 replicates required
LDF with copper powder added
Wick of fiber glass, apply and air dry
15 cycles to pass
Pass = no cracks

30. Qualification of Specimens
Run preliminary test with Mattsson’s solution
ASTM G 37
1 cycle to fail specimen
Must complete test before running LDF samples
Ammonia from Mattsson’s solution will contaminate atmosphere

32. Control Test Solution: DI water plus copper powder
Run simultaneously with LDF samples
Same specimens as LDF
15 cycles required
No cracks means LDF test valid

33. LDF Specification: ASTM G188
Requirement for LDF to pass ASTM G186
Responsibility of LDF manufacturer
Sampling plan required
Label to show that LDF meets ASTM 188 required

34. Who Needs ASTM G 186/188? LDF manufacturers and suppliers
Users of compressed gas systems
Labs
Hospitals
Users of welding equipment
Industrial gas companies
Independent labs desiring to do qualifications of LDFs

35. Types of Standards Test methods (TM) Standard Practice (SP) aka RP
ASTM G186
ASTM G 5-Reference Method
Standard Practice (SP) aka RP
NACE SP 0294
NACE RP 0205
Specification
ASTM G188

36. Summary: Who Needs Corrosion Standards?
Industries dealing with corrosive situations
Engineers and designers
Governments specifying materials for projects
Academics teaching how to use materials in the real world

37. Why Use Corrosion Standards?
Improve safety of equipment and systems
Improve reliability
Minimize unplanned shutdowns
Reduce cost of operation
Improve efficiency
Avoid duplication of effort

38. Thank You! Wayne France Len Rowe Bob Baboian Harvey Hack Sally Ketcham
Alan Fabiszewski
Florian Mansfeld
Sankara Papavinasam
Ed Hibner
Scott Whitlow
Steve Brubaker
Bob Smallwood
Kang Xu
Bill Watkins
John Scully