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Grain Boundary Segregation Behavior in 2.25Cr-1Mo Steel During Reversible Temper Embrittlement

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Abstract

Low alloy steels serving for a long time at high temperature, e.g., around 500 °C, are very sensitive to temper embrittlement due to segregation of various trace elements at prior austenite grain boundaries and/or carbide/matrix interfaces. This type of segregation in combination with various environmental effects can adversely affect the fracture resistance and fatigue crack propagation rate with subsequent change in fracture morphology of low alloy steels. This article describes the segregation behavior of various elements in 2.25Cr-1Mo pressure vessel steel investigated by AES, FEG-STEM, SEM, and EDS analyses. As confirmed by AES and FEG-STEM, phosphorus is found to be the main embrittling element for isothermal embrittlement. Sulfur and Mo segregation is only evident after longer embrittlement times. In the step-cooling embrittlement, phosphorus is still found to be the main embrittling element, but heavy segregation of sulfur in some isolated intergranular facets was also observed. For P segregation, a Mo-C-P interaction is observed, while sulfur segregation is attributed to site competition between sulfur and carbon atoms.

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References

  1. Islam M.A., Knott J.F., Bowen P. Critical Level of Intergranular Fracture to Affect the Toughness of Embrittled 2.25Cr-1Mo Steels. J. Mater. Eng. Perform. 2004, 13(5), 600-606

    Article  CAS  Google Scholar 

  2. M.A. Islam, “Intergranular Fracture in 2.25Cr-1Mo Pressure Vessel Steel at Low Temperatures,” Ph.D. Thesis, The University of Birmingham, U.K., 2001

  3. Islam M.A., Novovic M., Bowen P. Knott J.F. (2003) Effect of Phosphorus Segregation on Fracture Properties of 2.25Cr-1Mo Pressure Vessel Steel. J. Mater. Eng. Perform. 12(3), 244-248

    Article  CAS  Google Scholar 

  4. Nishioka K., Knott J.F. (1990) Effects of Environment on the Occurrence of Intergranular Facets During Fatigue Crack Propagation in 9Cr-1Mo Steel. Mech. Engr. Publications, London, 241-254

    Google Scholar 

  5. Islam M.A., Bowen P., Knott J.F. (2005) Intergranular Fracture on Fatigue Fracture Surface of 2.25Cr-1Mo Steel at Room Temperature in Air. J. Mater. Eng. Perform. 14(1), 28-36

    Article  CAS  Google Scholar 

  6. BS 7448 “Fracture Mechanics Toughness Tests, Part 1, Method for Determination of KIC, Critical CTOD and Critical J Values of Metallic Materials,” 1991, p 2677-2710

  7. Naudin C., Frund J.M., Pineau A. Intergranular Fracture Stress and Phosphorus Grain Boundary Segregation of a Mn-Ni-Mo Steel. Scripta Mater. 1999, 40, 1013-1019

    Article  CAS  Google Scholar 

  8. Yu J., McMahon C.J. Jr. (1980) Effect of Composition and Carbide Precipitation on Temper Embrittlement of 2.25Cr-1Mo Steel: Part 1. Effect of P and Sn. Met. Trans. 11A, 277-289

    Article  CAS  Google Scholar 

  9. Thomson R.C., Miller M.K. (1998) Carbide Precipitation in Martensite During the Early Stages of Tempering in Cr-and-Mo-Containing Low Alloy Steels. Acta Mater. 46(6), 2203-2213

    Article  CAS  Google Scholar 

  10. Wada M., Hosoi K., Nishiwaka O. (1982) FIM Observation of 2.25Cr-1Mo Steel. Acta Metall. 30, 1005-1011

    Article  CAS  Google Scholar 

  11. Islam M.A., Knott J.F., Bowen P. Kinetics of Phosphorus Segregation and its Effect on Low Temperature Fracture Behaviour in 2.25Cr-1Mo Pressure Vessel Steel. J. Mater. Sci. Technol. 21(1), 76-84, 2005

    Article  CAS  Google Scholar 

  12. Wada T., Hagel W.C. (1976) Effect of Trace Elements, Molybdenum and Intercritical HT on Temper Embrittlement of 2.25Cr-1Mo Steel. Met. Trans. A 7A, 1419-1426

    Article  CAS  Google Scholar 

  13. Yu J., McMahon C.J. Jr. (1980) Effect of Composition and Carbide Precipitation on Temper Embrittlement of 2.25Cr-1Mo Steel: Part 2. Effect of Mn and Si. Met. Trans. 11A, 291-300

    Article  CAS  Google Scholar 

  14. Briant C.L., Banerji S.K. (1979) Phosphorus Induced 350 °C Embrittlement in an Ultra High Strength Steel. Met. Trans. A 10, 123-131

    Article  Google Scholar 

  15. Shin K.S., Tsao T. (1988) Effect of Carbon on Grain Boundary Segregation of Sulfur in Iron. Scripta Metall. 22, 585-588

    Article  CAS  Google Scholar 

  16. Suzuki S., Obata M., Abiko K., Kimura H. (1983) Effect of Carbon on the Grain Boundary Segregation of P in Alpha-iron. Scripta Metall. 17, 1325-1328

    Article  CAS  Google Scholar 

Download references

Acknowledgments

The author is highly grateful to ORS Authority of U.K. and also Professor J.F. Knott and Professor P. Bowen of School of Metallurgy and Materials, University of Birmingham, U.K. to provide financial help during this research work. He also acknowledges Chris Hardy for her co-operation during AES analysis.

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  1. Materials and Metallurgical Engineering Department, Bangladesh University of Engineering and Technology (BUET), Dhaka, 1000, Bangladesh

    M.A. Islam

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Islam, M. Grain Boundary Segregation Behavior in 2.25Cr-1Mo Steel During Reversible Temper Embrittlement. J of Materi Eng and Perform 16, 73–79 (2007). https://doi.org/10.1007/s11665-006-9011-1

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  • DOI: https://doi.org/10.1007/s11665-006-9011-1

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