• CORROSION AND PROTECTION
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• v.12 no.1
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• pp.30-38
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• 2013

Austenitic stainless steels and Ni-base alloys are widely used as structural materials for major components and piping system in pressurized water reactors (PWRs). These austenitic alloys are known to be susceptible to environmental assisted cracking (EAC), such as environmentally-assisted fatigue (EAF) and primary water stress corrosion cracking (PWSCC) during long-term exposure to PWR primary water environment. In this paper, the current understanding on the phenomena and mechanisms of these EAC are briefly introduced using experimental results and literature review. The mechanisms for EAF and PWSCC for austenitic stainless steels and Ni-base alloys are discussed. Currently, austenitic stainless steels are known to be more susceptible to EAF, while less susceptible to PWSCC than Ni-base alloys. The possible explanations to such behaviors are proposed and discussed in view of the role of hydrogen and internal oxidation.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.280-280
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• 2001

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.1 s.173
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• pp.156-162
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• 2000

Sensitized STS 304 stainless steel crack growth rate(CGR) in high temperature water was investigated under trapezoidal wave loading test using fracture mechanics techniques. The CGR, due to stress corrosion cracking(SCC), were systematically measured as a function of the stress intensity factor and stress. holding time under trapezoidal wave loading. In high temperature water, CGR was enhanced by a synergistic effects in combination with an aggressive environment and mechanical damage. The CGR, $(da/dN)_{env}$ was basically described as a summation of the environmentally assisted crack growth rate $(da/dN)_{SCC}$, $(da/dN)_{CF}$ and fatigue crack growth rate in air $(da/dN)air,. The CGR, $(da/dN)_{env}$, increased linearly with increasing stress holding time. The CGR, $(da/dN)_{SCC}$ decreased linearly with increasing stress holding time. Fracture surface mode varied from trans-granular cracking to inter-granular cracking with increasing stress holding time.