TY - GEN
T1 - A review and assessment of cold-work influence on SCC of austenitic stainless steels in light water reactor environment
AU - Garud, Y. S.
AU - Ilevbare, G. O.
PY - 2009
Y1 - 2009
N2 - The growing recognition of cold-work as an accelerant in stress corrosion cracking (SCC) is well justified by its common or persistent impact as a key factor in both the initiation and crack growth regimes. More significantly, this accelerating effect is also clear from several of the service related failures (locations and failure times), and its assessment becomes a potentially critical issue for extended service well beyond 40 or 60 years. Both, the surface layer limited cold-work and the through-thickness condition need to be assessed for their impact on the remaining useful life of many components. This includes mechanically-strained conditions due to weld-shrinkage and cold-bent elbows or similar geometries which result in volumetric effects of cold-working as well. As such, the control of fabrication, weld-repair, and mitigation strategies need to address the cold-work factor, preferably with some basis and quantitative approach. The above aspects are reviewed in this paper with focus on the non-precipitation-hardening stainless steels subject to the reactor water environments. Also, the related field observations and their significance in assessing the cold-work impact are discussed. It is shown that the residual stress including the strain-path and stress state, as well as the material condition seem to dominate the operating influence of cold-work on SCC. These are explicitly related to the SCC susceptibility in a quantitative framework discussed in this paper. The basis for inter-relation between the cold-work effects and SCC is presented in relation to the model parameters. Additional factors pertinent to the austenitic steels include their susceptibility to sensitization and phase transformation, particularly interacting with the presence and sequence of cold-work. Observations from the surveyed literature on these aspects are also discussed in relation to the proposed model.
AB - The growing recognition of cold-work as an accelerant in stress corrosion cracking (SCC) is well justified by its common or persistent impact as a key factor in both the initiation and crack growth regimes. More significantly, this accelerating effect is also clear from several of the service related failures (locations and failure times), and its assessment becomes a potentially critical issue for extended service well beyond 40 or 60 years. Both, the surface layer limited cold-work and the through-thickness condition need to be assessed for their impact on the remaining useful life of many components. This includes mechanically-strained conditions due to weld-shrinkage and cold-bent elbows or similar geometries which result in volumetric effects of cold-working as well. As such, the control of fabrication, weld-repair, and mitigation strategies need to address the cold-work factor, preferably with some basis and quantitative approach. The above aspects are reviewed in this paper with focus on the non-precipitation-hardening stainless steels subject to the reactor water environments. Also, the related field observations and their significance in assessing the cold-work impact are discussed. It is shown that the residual stress including the strain-path and stress state, as well as the material condition seem to dominate the operating influence of cold-work on SCC. These are explicitly related to the SCC susceptibility in a quantitative framework discussed in this paper. The basis for inter-relation between the cold-work effects and SCC is presented in relation to the model parameters. Additional factors pertinent to the austenitic steels include their susceptibility to sensitization and phase transformation, particularly interacting with the presence and sequence of cold-work. Observations from the surveyed literature on these aspects are also discussed in relation to the proposed model.
UR - http://www.scopus.com/inward/record.url?scp=78649342398&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:78649342398
SN - 9781617388538
T3 - 14th International Conference on Environmental Degradation of Materials in Nuclear Power Systems Water Reactors 2009
SP - 780
EP - 790
BT - 14th International Conference on Environmental Degradation of Materials in Nuclear Power Systems Water Reactors 2009
T2 - 14th International Conference on Environmental Degradation of Materials in Nuclear Power Systems Water Reactors 2009
Y2 - 23 August 2009 through 27 August 2009
ER -