Crack growth testing on Cold Worked Alloy 690 in Primary Water Environment

2011 ◽  
pp. 71-89 ◽  
Author(s):  
David R. Tice ◽  
Stuart L. Medway ◽  
Norman Platts ◽  
John W. Stairmand
Keyword(s):  
Crack Growth ◽  
Water Environment ◽  
Alloy 690 ◽  
Primary Water ◽  
Cold Worked

Continuity of Environmentally Assisted Fatigue and Stress Corrosion Cracking Based on Short Crack Growth Behavior of 316 Stainless Steel in Simulated PWR Primary Water

2017 ◽  
Author(s):  
Choongmoo Shim ◽  
Yoichi Takeda ◽  
Tetsuo Shoji
Keyword(s):  
Stainless Steel ◽  
Stress Corrosion ◽  
Crack Growth ◽  
Stress Corrosion Cracking ◽  
Water Environment ◽  
Growth Behavior ◽  
Corrosion Cracking ◽  
Short Crack ◽  
Crack Growth Behavior ◽  
Primary Water

Environmental correction factor (Fen) is one of the parameters to evaluate the effect of a pressurized high temperature water environment. It has been reported that Fen for stainless steel saturates at a very low strain rate. However, the relationship between environmentally assisted fatigue (EAF) and stress corrosion cracking (SCC) is still unclear. The aim of this study is to investigate the short crack growth behavior and possible continuity of EAF and SCC at very low strain rates. Short crack initiation and propagation have similar behaviors, which retard the crack growth between 100–200 μm in depth. We find that the striation spacing correlates well with the maximum crack growth rate (CGR) data. Based on the correlation, it is clarified that the local CGR on an intergranular facet was faster than that on a transgranular facet. Furthermore, the overall maximum and average CGR from the EAF data is well interpreted and compared with the SCC data.

scholarly journals Fatigue Damage Management According to Performance Based Maintenance (PBM) Concept

2021 ◽  
Author(s):  
Masayuki Kamaya
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Thermal Loading ◽  
Water Environment ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Term Operation ◽  
Primary Water ◽  
Crack Growth Curve

Abstract A maintenance concept of performance based maintenance (PBM) has been proposed by the current author. According to the PBM concept, inspection results are considered in determining the next inspection schedule. In this study, this concept was applied to fatigue degradation for stainless steel components in the pressurized water reactor (PWR) primary water environment. It is possible to estimate the fatigue life for the PWR water environment from that obtained in an air environment and the parameter Fen, which represents the ratio of the fatigue life in the air and PWR water environments. It was shown that the fatigue life prediction using Fen can be replaced by the crack growth analysis using the growth rate for the PWR water environment. Then, the crack growth was predicted for a thermal loading assuming the growth occurred in the PWR water environment. It was shown that the duration until the next inspection could be optimized based on the inspection results together with the crack growth curve. A long term operation before the inspection resulted in a longer duration until the next inspection.

PWSCC of Nickel Base Alloys in Vapor Phase Environment of Pressurizer

2008 ◽  
Author(s):  
Takao Tsuruta ◽  
Kenji Sato ◽  
Seiji Asada ◽  
Takaaki Kobayashi ◽  
Koji Okimura ◽  
...  
Keyword(s):  
Weld Metal ◽  
Liquid Film ◽  
Vapor Phase ◽  
Water Environment ◽  
Alloy 600 ◽  
Alloy 690 ◽  
Primary Water ◽  
The Difference ◽  
Nickel Base ◽  
Susceptibility Tests

PWSCC incidents of Alloy 600 in vapor phase environment of pressurizer have been confirmed at several PWR plants. Vapor phase of pressurizer is filled with vapor from primary water, and the inner surface is covered with liquid film. Chemistry of the liquid film may be different from primary water, and this may cause different PWSCC susceptibility. Therefore the chemistry of liquid film of vapor phase has been investigated using simulated mock-up tests, and PWSCC susceptibility of 152 weld metal and TT600 (SG tube) has been investigated under the chemistry of the liquid film of vapor phase and primary water. According to the result of the chemistry investigation tests using mock-up of pressurizer, the liquid film environment was evaluated as follows: DH2 concentration: 300cc/kg·H2O, B:150ppm, Li<0.1ppb, pH320°C:5.6 under the primary water chemistry condition is DH2 concentration:30cc/kg·H2O, B:1950ppm, Li:3.7ppm, pH340°C:6.9. DH2 concentration of the liquid film is ten times higher and pH is lower than that of primary water. PWSCC susceptibility tests have been performed under the environment of the liquid film and primary water. No PWSCC crack propagation of 152 weld metal is confirmed in vapor phase environment. Crack growth rate of TT600 in vapor phase environment of pressurizer is not particularly high compared with that in primary water environment. It is confirmed that Alloy 690 (152 weld metal) has no PWSCC susceptibility under vapor phase environment of pressurizer. The difference of PWSCC susceptibility for Alloy 600 between vapor phase of pressurizer and primary water environment is not significant.

Environmentally assisted crack growth in one-dimensionally cold worked Alloy 690TT in primary water

2012 ◽  
Vol 57 ◽  
pp. 81-88 ◽  
Author(s):  
Q.J. Peng ◽  
J. Hou ◽  
T. Yonezawa ◽  
T. Shoji ◽  
Z.M. Zhang ◽  
...  
Keyword(s):  
Crack Growth ◽  
Primary Water ◽  
Cold Worked

scholarly journals Effect of Cold Working and Long-Term Heating in Air on the Stress Corrosion Cracking Growth Rate in Commercial TT Alloy 690 Exposed to Simulated PWR Primary Water

2021 ◽  
Author(s):  
Toshio Yonezawa ◽  
Atsushi Hashimoto
Keyword(s):  
Stress Corrosion Cracking ◽  
Cold Working ◽  
Cold Work ◽  
Index Number ◽  
Defect Index ◽  
Alloy 690 ◽  
Primary Water ◽  
Cold Worked ◽  
Shape And Size

AbstractThe authors have previously reported that the number of cavities at or near grain boundary (GB) carbides in commercial thermally treated (TT) Alloy 690 increases with increasing cold work reduction ratio and with heating temperature in air. In the present work after very long-term heating in air, the number of cavities at or near GB carbides in cold worked commercial TT Alloy 690 was observed to saturate, and the shape and size of the cavities changed. The shape and size of cavities and cracks were categorized, and a GB defect index number was defined as a function of their number, shape and size. Stress corrosion cracking growth rates in a commercial TT Alloy 690 with various levels of cold work exposed to simulated PWR primary water at 633 K (360 °C) have been measured and correlated with the defined GB defect index number. Cavities and cracks in the same materials before and after long-term heating in air have also been correlated with the defined GB defect index number. For the heavily cold worked (≥ 15 pct) commercial TT Alloy 690, a good correlation has been observed between the PWSCCGR and the GB defect index number. By contrast, for lightly cold worked (≤ 10 pct) commercial TT Alloy 690, the SCCGR in the simulated PWR primary water was very low and the GB defect index number was usually zero, regardless of cold working reduction ratio ≤ 10 pct. It is concluded that the mechanism of SCCGR for lightly cold worked TT Alloy 690 in PWR primary water is likely to be different from that for heavily cold worked TT Alloy 690.

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