Establishment of Yield Strength Using Sub-Size Samples without Gas Line Shutdown, Phase 2

Transcription

1 OTD-13/0005 Establishment of Yield Strength Using Sub-Size Samples without Gas Line Shutdown, Phase 2 (Mini, Full-Wall Longitudinal Specimens) Prepared by: Gas Technology Institute Des Plaines, Illinois March 2011

2 FINAL REPORT OTD Project No. 4.7.g / GTI Project No PHASE 2 - Establishment of Yield Strength Using Sub-size Samples without Gas Line Shutdown (Mini, Full-Wall Longitudinal Specimens) Report Issued: March 4, 2011 Prepared For: Operations Technology Development (OTD), NFP GTI Project Manager GTI Technical Contact: Ms. Alicia Farag Mr. Daniel Ersoy Program Manager R&D Director, Sr. Metallurgist alicia.farag@gastechnology.org daniel.ersoy@gastechnology.org Gas Technology Institute 1700 S. Mount Prospect Rd. Des Plaines, Illinois GTI Team Members: Mr. Brian Miller Chief Metallurgical Technologist Jim Louis and Frank Hennessey, CAD, Fabrication, and Machining

3 Signature Page Print or typed First M. Last Signature Date AUTHOR: Daniel Ersoy Daniel Ersoy//S// 04 MAR 2011 Title: Sr. Metallurgist and Principal Investigator CO-AUTHOR: Brian Miller Brian Miller//S// 04 MAR 2011 Title: Chief Metallurgical Technologist REVIEWED BY/ RELEASED: Alicia Farag Alicia Farag//S// 04 MAR 2011 Title: Senior Engineer / Program Mgr Page ii

4 Legal Notice This information was prepared by Gas Technology Institute ("GTI") for Operations Technology Development NFP. Neither GTI, the members of GTI, the Sponsor(s), nor any person acting on behalf of any of them: Makes any warranty or representation, express or implied with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privatelyowned rights. Inasmuch as this project is experimental in nature, the technical information, results, or conclusions cannot be predicted. Conclusions and analysis of results by GTI represent GTI's opinion based on inferences from measurements and empirical relationships, which inferences and assumptions are not infallible, and with respect to which competent specialists may differ. Assumes any liability with respect to the use of, or for any and all damages resulting from the use of, any information, apparatus, method, or process disclosed in this report; any other use of, or reliance on, this report by any third party is at the third party's sole risk. The results within this report relate only to the items tested. Page iii

5 Table of Contents Signature Page... ii Legal Notice... iii Table of Contents... iv Table of Figures... v List of Tables... vi Executive Summary... 1 Background... 2 Test Methods Used... 5 Experimental... 6 Machining Method... 6 Tensile Test Procedure...11 Results and Discussions...14 Pipe Sample Set...14 Grain Size Analysis...15 Tensile Testing...21 Acicular Ferrite and Controlled Rolling...26 Correlation of Yield Strength Test Specimens Mini, Full-Wall Longitudinal vs. Full-Size Transverse...29 Conclusions and Summary...31 Recommendations...32 Appendix A Grain Size Anisotropy (Horizontal vs. Vertical) in the Longitudinal and Transverse Planes...33 Appendix B Mini, Full-Wall Tensile Specimen Stress-Strain Plots...34 References...96 Page iv

6 Table of Figures Page Figure 1. Dimensional Drawing of Mini, Full-Wall Tensile Test Specimen Figure 2. 3D Wire Mesh Model of Tensile Specimen Design Figure 3. Diameter Dependent Index Angle Calculation Figure 4. Coupon Clamp Down Figure 5. The Second Specimen In Progress. First Specimen s Outline and Tabs Are Still Visible Figure 6. The Second Specimen In the Sequence Completed and Being Retained By Its Tabs Figure 7. Cutting of Retention Tabs to Release Finished Tensile Specimen Figure 8. Completed Tensile Specimens Cut to Final Dimensions Figure 9. Test Specimen After Surface Preparation Figure 10. Specimen In Fixture with Extensometer Attached Figure 11. Specimen Test Report Figure 12. Box Plot of Grain Size Delta (L-T) Figure 13. Normal Probability Plot ASTM Grain Size Number Delta (Longitudinal Transverse) for All Pipes Figure 14. Box Plot Grain Size Delta Figure 15. Normal Probability Plot Estimated Yield Strength Delta from ASTM Grain Size Number Delta (L-T) for All Pipes Figure 16. Grain Size Calculated (Estimated) Yield Strength Delta from ASTM Grain Size No Figure 17. Scatter Plot of Diameter (D), Wall Thickness (t), D/t, Diameter/Specimen Width (D/W), and Yield Strength Delta. Sequenced in Increasing YS Delta Figure 18. Yield Strength Comparison Between Mini, Full-Wall Longitudinal and Full-Size Transverse Tests Figure 19. Ultimate Tensile Strength Comparison Between Mini, Full-Wall Longitudinal and Full-Size Transverse Tests Figure 20. Ratio of yield to ultimate tensile strength, R. Includes side-by-side values for: full-size transverse vs. mini, full-wall longitudinal specimens, labeled by steel type Figure 21. Normal Probability Plot - 0.2% Offset Yield Strength %Difference Mini vs. Full-Size Specimen Figure 22. Pipe 14 Near I.D. Surface Chaotic Acicular Ferrite Figure 23. Pipe 14 Transverse Section Near O.D. Polygonal Ferrite and Pearlite Figure 24. Normal Probability Plot - Normalized Full-Size Yield Strength Range Figure 25. Full-Size Transverse (y-axis) vs. Mini, Full-Wall (x-axis) Yield Strength Figure 26. Grain Size Difference (Horizontal vs. Vertical Directions) In the Longitudinal and Transverse Planes of the Pipe Wall. Includes Probable Mechanical and Thermo-Mechanical History Page v

7 List of Tables Table 1: Test Methods Used... 5 Table 2: Pipe Specimen Critical Attributes That Could Affect Yield Strength Orientation Table 3: Average Longitudinal vs. Transverse Grain Size Difference and Affect on Yield Strength Table 4: Ave. Long-Transv. Grain Size Delta (L-T) Table 5: Yield Strength Delta Due to GS Delta (L-T) Table 6: Tensile Testing Results - Yield Strength (Mini, Full-Wall Longitudinal and Full-Size Transverse) Table 7: Tensile Testing Results Ultimate Tensile Strength (Mini, Full-Wall Longitudinal and Full-Size Transverse) Table 8: 0.2% Offset Yield Strength %Difference Mini vs. Full-Size Specimen Table 9: 0.2% Offset Yield Strength Normalized ½ Range for Full-Size Samples Page Page vi