Issue << content << Characterization of Cr-Mo Steel After High-Temperature Processing with Magnetic NDE Techniques


2008. . No. 2(40) - Jun 2008, pp. 72-74

Characterization of Cr-Mo Steel After High-Temperature Processing with Magnetic NDE Techniques

Amitava Mitra, J. N. Mohapatra, A. K. Panda, J. Swaminathan, R. N. Ghosh

Modified 9Cr-1Mo steel is a candidate material for pres­sure vessels and piping components. This steel owing to its high temperature strength, good creep resis­tance and excellent corrosion resistance finds potential applications in thermal environments. However, prolonged exposure of these materials under high temperature and stress causes microstructural changes, which ultimately lead to failure of the components. Magnetic hysteresis loop measurement and magnetic Barkhausen emis­sion techniques have been used to assess the ageing and creep behavior of this steel. The microstructural changes in the form of carbide precipitation and carbide growth during ageing and creep have been found to reveal different magnetic signals. A significant change in magnetic property has been observed corresponding to the three different stages of creep damage.
  1. Jiles D. C. Magnetic properties and microstruc­ture of AISI 1000 series carbon steels. – J. Phys. D: Appl. Phys. 1988. V. 21. No. 7. P. 1186-1195.
  2. Ryu K. S.; Nahm S. H.; Kim Y. B. et al. Depen­dence of magnetic properties on isothermal heat treatment time for 1Cr-1Mo-0.25V steel – J. Mag. Mag. Mat. 2000. V. 222. No. 1-2, P. 128–132.
  3. Das S. K., Joarder A., Mitra A. Magnetic Barkhausen emissions and microstructural degra­dation study in 1.25 Cr–0.50 Mo steel during high temperature exposure. – NDT & E. International. 2004. V. 37. P. 243–248.
  4. Moorthy V., Vaidyanathan S., Jayakumar T., Baldev Raj. On the influence of tempered micro­structures on magnetic Barkhausen emission in ferritic steels. – Phil. Mag. 1998. V. A 77. No. 6. P. 1499–1514.
  5. Bhadeshia H. K. D. H. Bainite in steels. – London: The Institute of Materials, 1992, 329 p.
  6. Wada T., Doane D. V. – Met. Trans. 1974. V. 5. P. 231.
  7. Brummer S. M., Viswanathan R., Richman R. H. – In: Intern. Conf. on Life Assessment and Exten­sion. 1988, p. 92–98.
  8. Watanabe Y., Shoji T. The evaluation of in-service materials degradation of low-alloy steels by the electrochemical method. – Metallurg. Mat. Trans. A. 1991. V. 22. No. 9. P. 2097–2106.
  9. Yu K. M., Nahm S. H., Kim Y. I. Toughness degradation evaluation of 1Cr–1Mo–0.25V steel by electrical resistivity. – J. Mater. Sci. Lett. 1999. V. 18. No. 14. P. 1175–1176.
  10. Drew M., Humphries S., Thorogood K., Barnett N. Remaining life assessment of carbon steel boiler headers by repeated creep testing – Int. J. Pressure Vessels and Piping. 2006. V. 83. No. 5. P. 343–348.
  11. Ohtani T., Ogi H., Hirao M. Evolution of microstructure and acoustic damping during creep of a Cr–Mo V ferritic steel. – Acta Materialia. 2006. V. 54. No. 10. P. 2705–2713.
  12. Mitra A., Mohapatra J. N., Swaminathan J. et al. Magnetic evaluation of creep in modified 9Cr–1Mo steel. – Scripta Materialia. 2007. V. 57. No. 9. P. 813–816.
  13. Mohapatra J. N., Panda A. K., Gunjan M. K. et al. Ageing behavior study of 5Cr–0.5Mo steel by magnetic Barkhausen emissions and magnetic hysteresis loop techniques – NDT & E Internat. 2007. V. 40. P. 173–178.
  14. Govindaraju M. R., Kaminski D. A., Devine M. K. et al. Nondestructive evaluation of creepdamage in power-plant steam generators andpiping by magnetic measurements. – Ibid. 1997. V. 30No. 1. P. 11–17.
  15. Das S., Joarder A. Effect of long-term service exposure at elevated temperature on microstructural changes of 5Cr–0.5Mo steels. – Metallurg. Mat. Trans. A. 1997. V. 28. No. 8. P. 1607–1616.


5 Udelny Pr.
St. Petersburg
007 812 670 7609

NDT World, Russian Quarterty Journal
©2000-2016 All rights reserved