High Temperature Hydrogen Attack Resistance Using Autoclave Testing of Scoop Samples SM Tim Munsterman Antonio Seijas Dana G. Williams, P.E. Technology Director – Engineering. Mechanical Engineering Consultant Materials & Corrosion Specialist Lloyd’s Register Capstone, Inc. Marathon Petroleum Co, LLC Houston, Texas USA Ashland, Kentucky USA Presented by: Dr John Fuad Edwards Haed of Integrity Services Lloyd’s Register Kuala Lumpur
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
High Temperature Hydrogen Attack Resistance Using Autoclave Testing of Scoop SamplesSM
Tim Munsterman Antonio Seijas Dana G. Williams, P.E. Technology Director –
Engineering. Mechanical
Engineering Consultant Materials & Corrosion Specialist
Lloyd’s Register Capstone, Inc. Marathon Petroleum Co, LLC Houston, Texas USA Ashland, Kentucky USA
Presented by:
Dr John Fuad Edwards
Haed of Integrity Services
Lloyd’s Register
Kuala Lumpur
March 6-8 2012
API Singapore 2012
• Introduction • Industry Dilemma • Scoop SamplerSM • Autoclave Testing • Real Time Monitoring • Data Interpretation • Conclusions
March 6-8 2012
API Singapore 2012
Introduction API 941 High Temperature Hydrogen Attack curves.
• 1976 Guard Reactor in a Distillate Hydrotreater Unit
• A302-B C-Mn- ½Mo Steel • Operating 110C (230oF) above CS
Curve • High Potential for HTHA based on
API 581 Risk Based Inspection • No damage found so far, however,
limited prior inspections • Scoop Sample Removal for
Toughness Testing and HTHA Testing
Carbon Steel Curve
C ½ Mo Curve
100 Hr Curve
Test Conditions
4H + FeC↔CH4 + Fe (atomic hydrogen reacting with iron carbides)
March 6-8 2012
API Singapore 2012
Industry Dilemma: How to tell Good from Bad C ½ Mo Steel?
• Microstructure analysis not reliable for HTHA resistance. • Current HTHA models incorporate range of HTHA Susceptibility,
Probability or Carbon Activity • There is no method to measure Carbon Activity • Actual HTHA Resistance Is Not Known • LR Capstone Approach is Straightforward:
• Perform a Test Using Vessel Material to Determine Properties • Similar Concept to Accelerated Creep Testing • Elevated Temperatures and Pressures using H2
• Remove Samples From Vessel • LR Capstone’s Scoop SamplerSM • Various Plates / Locations
March 6-8 2012
API Singapore 2012
Scoop SamplerSM
• Removes a spherical shaped samples – low stress concentration
• Attach tool using magnets • Uses a spherical cold cut saw blade
– no sparks • Local thin area calculations
performed prior to avoid repair welding
• Toughness can only be measured destructively
• Quantitative HTHA Resistance • Over 500 Scoop Samples Removed
March 6-8 2012
API Singapore 2012
Scoop Sample Locations – Guard Reactor
Lower Course
Top Head
Bottom Head
Upper Course
Scoop Sample 1
Scoop Sample 4
Scoop Sample 8
Scoop Sample 10
Scoop Sample 3
Scoop Sample 7
Scoop Sample 2
Scoop Sample 9
Scoop Samples 5
and 6
Impact Testing
Scoop Samples 11 and 12
HTHA Testing
• Performed both: • MPT Assessment
(Minimum Pressurization Temperature)
• HTHA Assessment • Samples removed from each shell
course and head (bottom head was not accessible at time of testing)
• Weld metal and HAZ’s included. • Nozzles can be sampled.
March 6-8 2012
API Singapore 2012
Scoop Samples Removed from Guard Reactor
March 6-8 2012
API Singapore 2012
High Temperature Hydrogen Autoclaves
97 bara H2 538°C
March 6-8 2012
API Singapore 2012
Full Immersion Coupon for Real Time Incipient Damage Monitoring
• 0.25” diameter x 0.375 long
March 6-8 2012
API Singapore 2012
Immersion Coupon Microstructure After Testing Displacement Monitoring of Coupon HTHA Swelling
• Hydrogen reacts with carbon to form methane.
• Methane trapped sub surface
• Intergranular methane bubbles (voids) and cracking
• Coupon swells with damage.
• Incipient damage when rate is non- linear
March 6-8 2012
API Singapore 2012
Carbon Steel Reference Coupon
• Displacement data is continuously monitored during HTHA testing
• Change in rate indicates incipient threshold
• Test duration based on time to incipient damage
March 6-8 2012
API Singapore 2012
C ½ Mo Coupon from Scoop Sample 11 (Upper Course)
• Displacement data showed growth during entire HTHA test
• Change in rate indicated incipient threshold
• Similar to a shift from second to third stage creep
March 6-8 2012
API Singapore 2012
• Displacement data indicated continuous growth during HTHA testing
• Change in rate indicated incipient threshold
• Jump in displacement likely due to blister formation
C ½ Mo Coupon from Scoop Sample 9 (Top Head)
March 6-8 2012
API Singapore 2012
• Surface Exposed to H2
• Large blister at center of coupon
• Many smaller blisters • Cross sectioned this
coupon for depth of damage
C ½ Mo Coupon from Scoop Sample 6 (Lower Course) Single Side Exposure - 830 Hours
March 6-8 2012
API Singapore 2012
• One side exposure coupon
• Cross section view for depth of damage
• 39.5% through-wall damage
• High Resistance to HTHA
C ½ Mo Coupon from Scoop Sample 6 (Lower Course)
Single Side Exposure - 830 Hours
March 6-8 2012
API Singapore 2012
• Cross section view for depth of damage
• 75% Through Wall HTHA Damage
• Incipient Damage Occurred in 10 Hours.
Carbon Steel Ref. Coupon
Single Side Exposure - 181 Hours
March 6-8 2012
API Singapore 2012
• Cross section view for depth of damage
• 7.4% Through Wall HTHA Damage
• Incipient Damage Occurred in 151 Hours.
Scoop Sample 5 C ½Mo Coupon
Single Side Exposure - 181 Hours
March 6-8 2012
API Singapore 2012
Data Interpretation • API 941 Incipient Damage Curves • Better Approach: The Pw parameter
• Amount of time to incipient damage • First developed by Shewmon • Refined by Japan Pressure Vessel Research Council (JPVRC) • Included in the Technical Basis for 941 Report, Appendix F
Pw= - 3 ln(PH2)-ln(t)+190000/(8.3145 T) Where: PH2 = hydrogen partial pressure in MPa,
t = time in hours, T= temperature in K
March 6-8 2012
API Singapore 2012
HTHA Test Results with Pw Calculations
Test Samples T, °C P, bara Hours to Incipient Damage
API 941 App. A-1
Critical Pw 20 yr
No Attack
Pw Calculated
Projected Years to
Increase in Risk
Carbon Steel (516-70) Sample 545 97 10 ----
Scoop Sample# 11 (Upper Course) 544 97 110 16.43 110
Scoop Sample# 5 (Lower Course) 538 97 151 16.33
Sample# 9 (Top Head) 538 97 159 16.28
Scoop Sample# 6 (Lower Course) 538 97 232 15.90
C ½ Mo Current Op. Conditions 402 34 17.75 30
March 6-8 2012
API Singapore 2012
Conclusions • Reactor has similar or better resistance than “good” C
½ Mo steel • Reactor is suitable for this service • Reactor will move to a medium potential for HTHA
damage after 30 years of operation. • It is recommended to perform HTHA inspections
based on risk based guidelines given in API 581 or similar.
March 6-8 2012
API Singapore 2012
Conclusions • The upper course and top head displayed lower HTHA
resistance • Recommended more thorough inspections of these
plates and fewer locations on the lower course • Typical RBI assessment for a C ½ Mo vessel
operating 110°C (230oF) above the carbon steel curve: • High likelihood after just 250 hours of exposure
(based on API 581, Appendix I, Table I-3).
The Lloyd’s Register Group works to enhance safety and approve assets and systems at sea, on land and in the air.
Services are provided by members of the Lloyd’s Register Group Lloyd’s Register, Lloyd’s Register EMEA and Lloyd’s Register Asia are exempt charities under the UK Charities Act 1993.
Thank you for listening
For more information: Tim Munsterman Phone 1-281-649-2212 Mobile 1-281-414-2136 Fax 1-281-493-5161 Engineering Services Lloyd’s Register Capstone, Inc. 1505 Highway 6 South Suite 100 Houston, TX 77077 [email protected] www.lr.org
Related Documents
