Surface Condition

During fabrication of components from Grade 91 steel, when weld repair of surface imperfections, such as grinding marks or arc strikes, is conducted, as permitted in the applicable engineering Code, a PWHT must be applied in accordance with the provisions of Section 2.6 of this report, “Welding Practices.”

Note that with respect to repair welds, it is recommended that instructions be included in the purchasing requirements that specify that the weld filler metal used by the producer for repair welding conform to the requirements of Section 2.6.4.1 of this report.

Section 3: References

1. J. R. DiStefano and V. K. Sikka, “Summary of Modified 9Cr-1Mo Steel Development Program, 1975–1985,” Oak Ridge National Laboratory, October 1986. ORNL-6303.

2. J. F. King, V. K. Sikka, M. L. Santella, J. F. Turner, and E. W. Pickering,

“Weldability of Modified 9Cr-1Mo Steel,” Oak Ridge National Laboratory, September 1986. ORNL-6299.

3. C. R. Brinkmann, V. K. Sikka, J. A. Horak, and M. L. Santella, “Long Term Creep Rupture Behavior of Modified 9Cr-1Mo Steel Base and Weldment Behavior,” Oak Ridge National Laboratory, November 1987.

ORNL/TM-10504.

4. Service Experience with Grade 91 Components. EPRI, Palo Alto, CA: 2009.

1018151.

5. Service Experience with Creep Strength Enhanced Ferritic Steels in Power Plants in the Asia-Pacific Region. EPRI, Palo Alto, CA: 2015. 3002005089.

6. Evaluation of Grade 91 Creep Rupture Strength as a Result of Heat Treatment Around the Intercritical Zone. EPRI, Palo Alto, CA: 2008. 1015818.

7. J. D. Parker and J. Henry, “The Performance of Creep-Strengthened Ferritic Steels in Power Generating Plant,” Proceedings of CREEP8, Eighth

International Conference on Creep and Fatigue at Elevated Temperatures, ASME, San Antonio, TX (July 22–26, 2007). Paper 26368.

8. The Benefits of Improved Control of Composition of Creep-Strength-Enhanced Ferritic Steel Grade 91. EPRI, Palo Alto, CA: 2014. 3002003472.

9. The Influence of Steel Making and Processing Variables on the Microstructure and Properties of Creep Strength Enhanced Ferritic (CSEF) Steel Grade 91. EPRI, Palo Alto, CA: 2014. 3002004370.

10. Best Practice Guideline for Well-Engineered Weld Repair of Grade 91 Steel.

EPRI, Palo Alto, CA: 2014. 3002003833.

11. Metallurgical Guidebook for Fossil Power Plants Boilers. EPRI, Palo Alto, CA: 2008. 1014183.

12. M. D. Bernstein and L. W. Yoder, Power Boilers: A Guide to Section I of the ASME Boiler and Pressure Vessel Code. ASME Press, New York: 1998.

13. B. W. Roberts, “Is Construction to the Code Good Enough?” Sixth Annual EPRI Conference on Welding and Repair Technology for Power Plants.

Sandestin, FL (June 2004).

14. ASME Boiler and Pressure Vessel Code, Section I, Rules for Construction of Power Boilers. American Society of Mechanical Engineers, New York, 2011.

15. Positive Material Identification Practice, ASME Boiler and Pressure Vessel Code, Nonmandatory Appendix B, Section I, Rules for Construction of Power Boilers. American Society of Mechanical Engineers, New York, 2011.

16. Embrittlement of Power Plant Steels. EPRI, Palo Alto, CA: 2013.

3002001474.

17. Evaluation of Factors Affecting the Accuracy of Field Post-Weld Heat Treatment.

EPRI, Palo Alto, CA: 2012. 1024722.

18. A Well-Engineered Approach for Establishing the Minimum Allowable Post-Weld Heat Treatment for Power Generation Applications of Grade 91 Steel. EPRI, Palo Alto, CA: 2015. 3002005350.

19. The Use of Portable Hardness Testing in Field Applications for Grade 91 Steel.

EPRI, Palo Alto, CA: 2012. 1024695.

20. A Perspective on the Selection of Preheat, Interpass and Post-Weld Cool Temperatures Using Grade 91 Steel as an Example. EPRI, Palo Alto, CA:

2015. 3002005351.

21. Creep Strength-Enhanced Ferritic (CSEF) Steel Welding Guide. EPRI, Palo Alto, CA: 2013. 1026584.

22. The T91/P91 Book, Vallourec & Mannesmann Tubes, Houston, TX: 1999.

23. S. J. Brett, “Early Type IV Cracking on Retrofit Grade 91 Steel Headers.”

Safety and Reliability of Welded Components in Energy and Processing Industry.

Graz University of Technology: 2008, pp. 225–231.

24. D. L. Newhouse, C. J. Boyle, and R. M. Curran, “A Modified 12-Perecent Chromium Steel for Large High Temperature Steam Turbine Rotors.” Paper presented at ASTM 68th Annual Meeting, Purdue University, Lafayette, IN, 1965.

25. EPRI Conference on 9Cr Materials Fabrication and Joining Technologies. EPRI, Palo Alto, CA: 2001. 1006299.

26. A. L. Schaeffler, “Constitution Diagram for Stainless Steel Weld Metal, Metal Progress 56(11): 680–680B, 1949.

27. H. Schneider, “Investment Casting of High-Hot Strength 12% Chrome Steel,” Foundry Trade Journal, Vol. 108, 1960, pp. 562–3.

28. J. P. Shingledecker and M. L. Santella, “Chemical Composition

Recommendations for ASME TG-CSEF Steels,” Presentation to ASME Boiler and Pressure Vessel Code Meeting, based on Research at ORNL supported by the U.S. Department of Energy (DOE), Office of Fossil Energy, Advanced Research Materials Program, under Contract DE-AC05-00OR22725 with UT-Battelle, LLC, 2009.

29. F. Masuyama, Summary of Analysis Results of Creep Strength for Modified 9Cr-1Mo Steel, Committee Correspondence,ASME committees SC-II, SG-SFA, 1993.

30. Advances in Materials Technology for Fossil Power Plants: Proceedings from the Sixth International Conference. EPRI Palo Alto, CA: 2011. 1022300. 2010.

31. R. Bruscato, “Temper Embrittlement and Creep Embrittlement of 21/4Cr1Mo Shielded Metal Arc Weld Deposits,” Welding Research Supplement, April 1970, pp. 148s–156s.

32. S. H. Lalam, H. K. D. H. Bhadheshia, and D. J. C. MacKay, “Bruscato Factor in Temper Embrittlement of Welds,” Science and Technology of Welding and Joining, Vol. 5, No. 5, pp. 338–340 (2000).

33. S. A. Kumar, Physical Metallurgy Handbook, McGraw-Hill, New York: 2003.

34. M. Santella and J. Shingledecker, “Prediction of A1 & Ms Critical

Transformation Temperatures for 9 & 12 Cr Steels,” Presentation in ASME Code Week, Las Vegas, NV (August 2006).

35. M. Santella and J. Shingledecker, “Analysis of Transformation Temperatures for Commercially Produced Advanced Ferritic Steels,” Presentation in ASME Code Meeting—TG Advanced Ferritic Steels, Atlanta, GA (January 28, 2007).

36. Metrode Welding Consumables, “Welding Consumables for P91 Steels for the Power Generation Industry,” Issue 6, July 2006, www.metrode.com.

37. G. C. Bodine, B. Chakravarti, C. M. Owens, B. W. Roberts, D. M.

Vandergriff, and C. T., Ward, “A Program for the Development of Advance Ferritic Alloys for LMFBR Structural Application,” Oak Ridge, TN

(September 1977), pp. 71–155. TR-MCD-015.

38. J. H. Holloman and L. D. Jaffe, “Time-Temperature Relations in Tempering of Steel,” AIME, Vol. 162, pp. 223–249 (1945).

39. The Effect of Variables on the Results of Field Hardness Testing of Grade 91 Steel.

EPRI, Palo Alto, CA: 2011. 1024694.

40. The Use of Portable Hardness Testing in Field Applications for Grade 91 Steel.

EPRI, Palo Alto, CA: 2012. 1024695.

41. Effects of Cold-Work and Heat Treatment on the Stress-Rupture Behavior of Grade 91 Material. EPRI, Palo Alto, CA: 2005. 1011352.

42. Stress Corrosion Cracking of Grade 91 Material. EPRI, Palo Alto, CA: 2007.

1013360.