scholarly journals Report of the US Nuclear Regulatory Commission Piping Review Committee. Volume 1. Investigation and evaluation of stress corrosion cracking in piping of boiling water reactor plants

1984 ◽  
Author(s):  
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Nuclear Regulatory Commission ◽  
Corrosion Cracking ◽  
Boiling Water ◽  
Boiling Water Reactor ◽  
Review Committee ◽  
Water Reactor ◽  
The Us ◽  
Regulatory Commission

Stress–Corrosion Cracking of Surface-Engineered Alloys in a Simulated Boiling-Water Reactor Environment

CORROSION ◽  
10.5006/2673 ◽  
2018 ◽  
Vol 74 (6) ◽  
pp. 635-653 ◽  
Author(s):  
W. Niu ◽  
Z. Li ◽  
F. Ernst ◽  
Z. Ren ◽  
C. Ye ◽  
...  
Keyword(s):  
Fracture Surface ◽  
Strain Rate ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Boiling Water ◽  
Boiling Water Reactor ◽  
Aisi 316L ◽  
Water Reactor ◽  
Water Composition

The potential of surface engineering by concentrated interstitial solute (SECIS) for improved resistance to stress–corrosion cracking (SCC) in a simulated boiling-water reactor (BWR) environment was studied for an austenitic stainless steel (AISI-316L) and a Ni-base superalloy (IN-718) via slow-strain-rate tests. For these tests, tensile rods of both alloys were carburized at a low temperature, which generates a concentrated solution (supersaturation: 105) of interstitially dissolved carbon within a ≈25 μm deep zone below the surface. In BWR-NWC (normal water composition), SECIS AISI-316L exhibits high susceptibility to SCC with a reduction in elongation and a fracture surface consistent with transgranular SCC (TGSCC). We found that the crack-tip strain rate plays an important role for crack initiation and propagation. To understand the role of concentrated interstitial carbon on the failure mode, we also studied specimens treated by ultrasonic nanocrystal surface modification (UNSM), a carbon-free method for surface hardening. We conclude that the carbon-rich zone enables nucleation of sharp cracks, which normally do not form in AISI-316L. Crack propagation in the underlying carbon-free alloy core and, ultimately, TGSCC failure, depends on the environment (solution and potential), as demonstrated by tests in BWR-HWC (hydrogen water composition). The stress–strain curve of SECIS IN-718, in contrast, is similar to that of non-treated material. In this case, the fracture surface was consistent with ductile failure.

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