Influence of microstructure on stress corrosion cracking of mild steel in synthetic caustic-nitrate nuclear waste solution

Thesis/Dissertation · Mon Dec 01 04:00:00 EST 1975

DOI:https://doi.org/10.2172/4088159· OSTI ID:4088159

Sarafian, Peter Gregory ^[1]

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1. Georgia Inst. of Technology, Atlanta, GA (United States)

The influence of alloy microstructure on stress corrosion cracking of mild steel in caustic-nitrate synthetic nuclear waste solutions was studied. An evaluation was made of the effect of heat treatment on a representative material (ASTM A 516 Grade 70) used in the construction of high activity radioactive waste storage tanks at Savannah River Plant. Several different microstructures were tested for susceptibility to stress corrosion cracking. Precracked fracture specimens loaded in either constant load or constant crack opening displacement were exposed to a variety of caustic-nitrate and nitrate solutions. Results were correlated with the mechanical and corrosion properties of the microstructures. Crack velocity and crack arrest stress intensity were found to be related to the yield strength of the steel microstructures. Fractographic evidence indicated pH depletion and corrosive crack tip chemistry conditions even in highly caustic solutions. Experimental results were compatible with crack growth by a strain- assisted anodic dissolution mechanism; however, hydrogen embrittlement also was considered possible.

• Research Organization: Georgia Inst. of Technology, Atlanta, GA (United States)
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• NSA Number: NSA-33-020695
• OSTI ID: 4088159
• Report Number(s): DP-MS--76-10
• Country of Publication: United States
• Language: English

Related Subjects

*RADIOACTIVE WASTE STORAGE
*SODIUM HYDROXIDES-- CORROSIVE EFFECTS
*SODIUM NITRATES-- CORROSIVE EFFECTS
*STEEL-ASTM-A516-- STRESS CORROSION
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
CRACKS
DISSOLUTION
EMBRITTLEMENT
FRACTURE PROPERTIES
HYDROGEN
LIQUID WASTES
MICROSTRUCTURE
PH VALUE
SIMULATION
YIELD STRENGTH