Microstructure and Mechanical Properties of CrMoV Steel after Long-Term Service

Open access

The paper presents the results of research on the microstructure and mechanical properties of 12HMF steel after longterm service. The investigated material was taken from a pipeline with circumferential welded joint after 419 988 hours of service at the temperature of 490°C, steam pressure 8 MPa. Performed research has shown that the 12HMF steel after service was characterized by a typical microstructure for this grade of steel, that is a ferritic-bainitic microstructure without any visible advanced processes of its degradation. The investigation of mechanical properties has shown that the examined steel after service was characterized by a very low impact energy KV, and yield strength lower than the required minimum. Whilst tensile strength and yield strength determined at elevated temperature was higher and similar to the standard requirements, respectively. It has been proved that the main cause of an increase in brittleness and a decrease in yield strength of the examined steel should be seen in the segregation of phosphorus to grain boundaries and the formation of precipitate free zones near the boundaries.

[1] A. Zieliński, J. Dobrzański, J. Wodzyński, Prace IMZ 1, 42 (2010).

[2] S. Stachura, Energetyka 2, 109 (1999).

[3] A. Jasiński, Energetyka 3, 551 (2013).

[4] J. Dobrzański, A. Zieliński, H. Paszkowska, Prace IMŻ 1, 9 (2009).

[5] PN-75/H-84024 Steels for elevated temperatures service. Grades.

[6] PN-EN ISO 643:2012 Steels - Micrographic determination of the apparent grain size.

[7] J. Janovec, A. Vyrostkova, M. Svoboda, Metall. Mater. Trans. 25A, 267 (1994).

[8] A. Vyrostkova, A. Kroupa, J. Janovec, M. Svoboda, Acta Mater. 46, 31 (1998).

[9] R.D. Fu, T.S. Wang, W. H. Zhou, W.H. Zhangc, F.C. Zhang, Mater. Character. 58, 968 (2007).

[10] Y. Zhang, H. Han, L. Miao, H. Zhang, J. Fi, Mater. Trans. 50A, 2507 (2009).

[11] G.D. Pigrova, Metall. Mater. Trans. 27A, 498 (1996).

[12] B.A. Senior, Mater. Sc. Eng., 103A, 263 (1988).

[13] G. Golański, P. Wieczorek, Arch. Found. Eng. 9, 97 (2009).

[14] J. Dobrzański: Materials science interpretation of the life of steels for power plants, Open Access Library, Gliwice 2011.

[15] A. Joarder, D.S. Sarma, N.S. Cheruvu, Metall. Trans. 22A, 1811 (1991).

[16] T.D. Nguyen, K. Sawada, H. Kushima, M. Tabuchi, K. Kimura, Mater. Sc. Eng. 591A, 130 (2014).

[17] R.M. Horn, R.O. Ritchie, Metall. Trans. 9A, 1039 (1978).

[18] Z. Qu, K. H. Kuo, Metall. Trans. 12A, 1333 (1981).

[19] S. Stachura. Z. Stradomski, G. Golański, Hutnik - Wiadomości Hutnicze 5, 184 (2001).

[20] G. Golański, Arch. Found. Eng. 9, 91 (2009).

[21] H. Erhart, H.J. Grabke, Metal Sc. 15, 401 (1981).

[22] M.A. Islam, M. Novovic, P. Bowen, J.F. Knott, J. Mater. Eng. Perform. 12, 244 (2003).

[23] J. Janovec: Nature of alloy steel intergranular embrittlement, Veda Publ., Bratislava, 1999.

[24] F. Abe, K. Asano, A. Fujiwara, Metall. Trans. 4, 1499 (1973).

[25] A. John, E. Wert, R. Parker, V. F. Zackay, Metall. Trans. 10A, 1313 (1979).

[26] K. Thorsten, B. Dietmar, N. Eckhard, Sc. Mater. 48, 1189 (2003).

[27] T. Węgrzyn, J. Piwnik, Arch. Metall. Mater. 2, 539 (2012).

[28] A. Zieliński, J. Dobrzański, H. Krztoń, J. Achiev. Mater. Manuf. Eng. 25, 33 (2007).

Archives of Metallurgy and Materials

The Journal of Institute of Metallurgy and Materials Science and Commitee on Metallurgy of Polish Academy of Sciences

Journal Information


IMPACT FACTOR 2016: 0.571
5-year IMPACT FACTOR: 0.776

CiteScore 2016: 0.85

SCImago Journal Rank (SJR) 2016: 0.347
Source Normalized Impact per Paper (SNIP) 2016: 0.740

Cited By

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 393 330 15
PDF Downloads 139 126 8