Effect of Grain Size on Corrosion Fatigue Behaviors of Primary Coolant Pipes of Nuclear Power Plants

Abstract:

Corrosion fatigue is one of the most important failure modes of primary coolant pipe used in nuclear power plant, due to the thermal cyclic stress caused by a variety of start-up and shutdown as well as transients when severed in the high temperature and pressure water environment. And 316LN stainless steel is one of the main materials used in pressurized water reactor in nuclear power plant. The mechanisms of fatigue crack initiation and propagation were elucidated by investigating the composition properties of oxide films formed in simulated service environment. The effects of grain size on the fatigue life and crack initiation mechanism of 316LN stainless steel in 320°C water environment were also investigated. The results indicated that the specimens with fine grains (30μm) own the longest fatigue lives than those with intermediate (80μm) and coarse grains (210μm). The fatigue stress amplitudes of the specimens increased with the grain refinement, although the fatigue lives of the specimens with intermediate and coarse grains were close. Fatigue cracks were often initiated at the persistent slip bands on the surfaces of the specimens with intermediate and coarse grains, while it was not easy to be initiated on the fine grain specimens. Finally, combined with the experimental results and the actual production of industry, a suggestion for the production of the primary coolant pipe is put forward.

• Periodical: Materials Science Forum (Volume 882)
• Pages: 124-129
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.882.124
• Online since: January 2017
• Authors: Ruoyun Zhang*
• Keywords: Corrosion Fatigue, Grain Size, High Temperature, Pressure Water, Primary Coolant Pipe

References

[1] J. D. Tucker, M. K. Miller, and G. A. Young, Assessment of thermal embrittlement in duplex stainless steels 2003 and 2205 for nuclear power applications., Acta Materialia 87 (2015): 15-24.

DOI: 10.1016/j.actamat.2014.12.012

[2] M. Wang, C. Lei, X. Liu, and X. Ma, Influence of thermal aging on the SCC susceptibility of wrought 316LN stainless steel in a high temperature water environment, Corrosion Science 81 (2014): 117-124.

DOI: 10.1016/j.corsci.2013.12.011

[3] T. Takeuch, Y. Kakubo, Y. Matsukawa, Y. Nozawa, T. Toyama, Y. Nagai, Y. Nishiyama, J. Katsuyamac, Y. Yamaguchic, K. Onizawac, and M. Suzukia, Effects of thermal aging on microstructure and hardness of stainless steel weld-overlay claddings of nuclear reactor pressure vessels, Journal of Nuclear Materials 452, no. 1 (2014).

DOI: 10.1016/j.jnucmat.2014.04.003

[4] K. H. Lo, C. T. Kwok, W. K. Chan, and D. Zeng, Corrosion resistance of duplex stainless steel subjected to long-term annealing in the spinodal decomposition temperature range., Corrosion Science 55 (2012): 267-271.

DOI: 10.1016/j.corsci.2011.10.027

[5] J. Zhou, J. Odqvist, M. Thuvander, S. Hertzman, and P. Hedström, Concurrent phase separation and clustering in the ferrite phase during low temperature stress aging of duplex stainless steel weldments., Acta Materialia 60. 16 (2012): 5818-5827.

DOI: 10.1016/j.actamat.2012.07.022

[6] Chandra, S. Kalyan, V. Shankar, K. Mariappan, R. Sandhya, and P. C. Chakraborty, Effect of strain rate on the low cycle fatigue behavior of 316L (N) stainless steel weld joints., Procedia Engineering 55 (2013): 176-180.

DOI: 10.1016/j.proeng.2013.03.239

[7] J. Marrow, D. Engelberg, A. Jivkov, P. Wood, L. Babout, and N. Stevens, Grain boundary control for improved intergranular stress corrosion cracking resistance in austenitic stainless steels: new approach., Energy Materials (2013).

DOI: 10.1179/174892406x142723

[8] D. T. Spencer, M. R. Edwards, M. R. Wenman, C. Tsitsios, G. G. Scatigno, and P. R. Chard-Tuckey, The initiation and propagation of chloride-induced transgranular stress-corrosion cracking (TGSCC) of 304L austenitic stainless steel under atmospheric conditions., Corrosion Science 88 (2014).

DOI: 10.1016/j.corsci.2014.07.017

[9] A. Järvenpää, L. P. Karjalainen, and M. Jaskar, Effect of grain size on fatigue behavior of Type 301LN stainless steel, International Journal of Fatigue 65 (2014): 93-98.

DOI: 10.1016/j.ijfatigue.2013.05.012

[10] T. P. Gabba, P. T. Kantzosb, J. Telesmana, J. Gaydaa, C. K. Sudbracka, and B. Palsa. Fatigue resistance of the grain size transition zone in a dual microstructure superalloy disk, International Journal of Fatigue 33. 3 (2011): 414-426.

DOI: 10.1016/j.ijfatigue.2010.09.022

[11] J. Zhang, and Y. Jiang, Fatigue of polycrystalline copper with different grain sizes and texture, International Journal of plasticity 22. 3 (2006): 536-556.

DOI: 10.1016/j.ijplas.2005.04.006

[12] X. Yang, J. Zhou, and X. Ling, Influences of surface grain size and gradient variation along depth on fatigue life of metallic materials., Materials & Design 43 (2013): 454-459.

DOI: 10.1016/j.matdes.2012.07.026

[13] C. A. Sweeney, B. O'Brien, F. P. E. Dunne, P. E. McHugh, and S. B. Leen, Strain-gradient modelling of grain size effects on fatigue of CoCr alloy, Acta Materialia 78 (2014): 341-353.

DOI: 10.1016/j.actamat.2014.06.044