A Review of Fatigue and SCC Crack Growth Rate Relationships for Ferritic and Stainless Steels and Ni-Cr-Fe Materials in BWR Environment

2006 ◽  
Author(s):  
Hardayal S. Mehta
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Corrosion Fatigue ◽  
Full Range ◽  
Water Environment ◽  
Plant Component

When in-service inspection of a nuclear plant component reveals the presence of cracking, an engineering evaluation (typically called a justification for continued operation, or JCO) is required to demonstrate the structural suitability for continued operation. A key element in such a flaw evaluation is the projected crack growth over the period when the cracked component will be reinspected. The crack growth is expected to be a combination of stress corrosion cracking (SCC) and corrosion fatigue. The ASME Section XI Code is in the process of developing a full range of SCC and corrosion fatigue crack growth rate relationships (CGRs) for stainless steel and Ni-Cr-Fe materials. The objective of this paper is to summarize several available SCC and fatigue crack growth rate relationships for these materials exposed to boiling water reactor (BWR) water environments. For completeness, low alloy steel SCC and corrosion fatigue CGRs in BWR water environment are also briefly reviewed. Two example evaluations are provided that used some of these CGRs in developing the JCOs for BWR components. A detailed comparison of these CGRs along with a review of the underlying data will be part of a future effort undertaken by the ASME Section XI Task Group.

scholarly journals Effect of Various Factors Produced by Welding on the Corrosion Fatigue Crack Growth Rate

1987 ◽  
Vol 36 (12) ◽  
pp. 774-780
Author(s):  
Toshio Terasaki ◽  
Tetsuya Akiyama ◽  
Masatoshi Eto ◽  
Yasuhumi Matsuo ◽  
Masaharu Kusuhara
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Corrosion Fatigue ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth

Effect of Hold-Time Interspersed With Cyclic Loading on Corrosion Fatigue Crack Growth Rate of a Steel in Sodium Chloride Solution

2018 ◽  
Author(s):  
Raghu V. Prakash ◽  
Dhinakaran Sampath
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Corrosion Fatigue ◽  
Hold Time ◽  
Corrosion Fatigue Crack ◽  
Corrosion Fatigue Crack Growth

Corrosion fatigue growth behavior of structural steels at low cyclic frequency is characterized by an increase in crack growth rate in the threshold and Paris regions, due to the simultaneous action of cyclic mechanical load (fatigue) and corrosive environment. Knowledge on the effect of load sequence on corrosion fatigue crack growth is important to set out the realistic design and prognosis criteria for components operating under corrosive environments. In this study, the corrosion fatigue crack growth rate under the effect of hold-time (1000s), at a maximum stress intensity factor (Kmax), interspersed during cyclic load on was studied experimentally on a Mn-Ni-Cr steel under 3.5% NaCl solution at a constant stress intensity factor range (ΔK) of 15 MPa √m; the corrosion crack growth rate was evaluated for three different frequencies of: 0.01, 0.1 and 1 Hz. As a result of hold time at the peak load, the exposure time for the crack-tip to interact with the environment increased, which could enhance the corrosion crack growth rates. To verify if this corrosion effect can be contained, electrode potential of (−) 850 mV and (−) 950 mV SCE was applied to the specimen to reduce the extent of corrosion contribution to crack growth rate. The fatigue crack growth rate (da/dN) increased when the frequency was decreased from 1 to 0.01 Hz at all electrode potentials. However, the crack growth rate at 0.01 Hz increased by an order of magnitude with a tensile hold at Kmax for 1000 s compared with the crack growth rate during continuous cyclic load for a given electrode potential. The crack growth rate reduced when the electrode potential was decreased to −950 mV SCE. The enhancement of corrosion fatigue crack growth rate with the introduction of a hold-time is explained using crack-tip strain rate assisted anodic dissolution.

Fatigue Crack Growth Rate for Nickel-Based Alloys in PWR Environment

2007 ◽  
Author(s):  
Yuichiro Nomura ◽  
Hiroshi Kanasaki
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Stress Ratio ◽  
Water Environment ◽  
Primary Water ◽  
Water Reactors

Reference fatigue crack growth rate (FCGR) curves for ferrite and austenitic stainless steels in light water reactors environments are prescribed in JSME S NA1-2004 in Japan. The reference FCGR curves in the environment in pressurized water reactors (PWR) are determined as functions of the stress intensity factor range, temperature, load rising time and stress ratio. However, similar reference FCGR curve for nickel-based alloys for PWR environment are not prescribed. In order to propose reference curve in PWR environment, fatigue tests of nickel-based alloys in a simulated PWR primary water environment were conducted. The results of the study show that FCGR in a PWR primary water environment increases with decreasing cyclic loading frequency f, increasing stress ratio R, and increasing temperature Tc.

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