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Title: Determination of the activation energy for SCC crack growth for Alloy 182 weld in a PWR environment.

Abstract

No abstract prepared.

Authors:
; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USNRC
OSTI Identifier:
982625
Report Number(s):
ANL/NE/CP-59819
TRN: US201015%%1235
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Conference
Resource Relation:
Conference: 13th International Conference on Environmental Degradation of Materials in Nuclear Power Systems; Aug. 19, 2007 - Aug. 23, 2007; Whistler, B. C., Canada
Country of Publication:
United States
Language:
ENGLISH
Subject:
29 ENERGY PLANNING, POLICY AND ECONOMY; ACTIVATION ENERGY; ALLOYS; CRACK PROPAGATION; ENVIRONMENT; MATERIALS; MEETINGS; NUCLEAR POWER; WELDED JOINTS

Citation Formats

Alexandreanu, B., Chopra, O. K., and Shack, W. J.. Determination of the activation energy for SCC crack growth for Alloy 182 weld in a PWR environment.. United States: N. p., 2007. Web.
Alexandreanu, B., Chopra, O. K., & Shack, W. J.. Determination of the activation energy for SCC crack growth for Alloy 182 weld in a PWR environment.. United States.
Alexandreanu, B., Chopra, O. K., and Shack, W. J.. Mon . "Determination of the activation energy for SCC crack growth for Alloy 182 weld in a PWR environment.". United States. doi:.
@article{osti_982625,
title = {Determination of the activation energy for SCC crack growth for Alloy 182 weld in a PWR environment.},
author = {Alexandreanu, B. and Chopra, O. K. and Shack, W. J.},
abstractNote = {No abstract prepared.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}

Conference:
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  • The crack growth response of alloy 152 and 52 weld metals has been measured in simulated PWR primary water at both high (325-350 C) and low (50 C) temperatures. Tests were performed on samples machined from alloy 152 or 52 mockup welds. Propagation rates under cycle + hold and constant K conditions at high temperatures show stable, but extremely low SCC growth rates. The most significant intergranular cracking occurred during cycling at 50 C, particularly for the alloy 152 weld metal at high stress intensity.
  • Significant intergranular (IG) crack growth during stress corrosion cracking (SCC) tests has been documented during tests in simulated PWR primary water on two alloy 152 specimens cut from a weldment produced by ANL. The cracking morphology was observed to change from transgranular (TG) to mixed mode (up to ~60% IG) during gentle cycling and cycle + hold loading conditions. Measured crack growth rates under these conditions often suggested a moderate degree of environmental enhancement consistent with faster growth on grain boundaries. However, overall SCC propagation rates at constant stress intensity (K) or constant load were very low in all cases.more » Initial SCC rates up to 6x10-9 mm/s were occasionally measured, but constant K/load growth rates dropped below ~1x10-9 mm/s with time even when significant IG engagement existed. Direct comparisons were made among loading conditions, measured crack growth response and cracking morphology during each test to assess IGSCC susceptibility of the alloy 152 specimens. These results were analyzed with respect to our previous SCC crack growth rate measurements on alloy 152/52 welds.« less
  • No abstract prepared.
  • No abstract prepared.
  • ZnO additions to boiling water reactor (BWR) water have been the focus of recent interest, primarily because of their beneficial influence in reducing buildup of radioactive species such as Co{sup 60} in the oxide film of structural components, e.g., stainless steel piping. The effect of ZnO additions on stress corrosion crack growth rates were studied using 1T CT fracture mechanics specimens of sensitized type 304 stainless steel, sensitized Alloy 600, and Alloy 182 weld metal exposed to {approx}288 C water containing various levels of dissolved oxygen and impurities. Zn levels of 5 to 100 ppb Zn{sup 2+} were evaluated andmore » found to reduce crack growth rates for all materials and in all water chemistries. Many Zn tests involved long term exposure and were performed at somewhat reduced corrosion potential (e.g., from {approx}+200 to 0 {minus}+50 mV{sub she}); variations in corrosion potential from +200, to +50, to {minus}50 mV{sub she} clearly had an important effect. The benefit of Zn appeared to be most pronounced when the growth rate was decreased (e.g., by corrosion potential). This was consistent with the findings of mechanistic studies, which showed that Zn decreased the repassivation response at times >10{sup 4} s, which is associated with low crack tip strain rates, i.e., low growth rates. Reduced corrosion potentials are also expected to directly effect Zn, since high (crack mouth) corrosion potentials inhibit the transport of Zn{sup 2+} into the crack. Zn also increased the fracture strain of the oxide on stainless steel, and may also reduce crack growth rates by increasing the pH in the crack. Similar benefits are expected for other structural materials, such as nonsensitized or irradiated stainless steel, carbon steel, low alloy steel, and other nickel alloys.« less