Fatigue crack growth of A508 steel in high-temperature, pressurized reactor-grade water
Fatigue crack growth tests of A508-2 pressure vessel steel have been conducted at two test temperatures (93 degrees C and 288 degrees C) using a variety of constant amplitude waveforms. The load ratios were either 0.1 or 0.125, and the water chemistry was carefully monitored and controlled so as to simulate the nominal pressurized water reactor chemistry. The test procedures are described, and an examination of all the data indicates that the results fall into one of two rather clearly defined categories. One band of data, termed 'low', lies close to or essentially on, the ASME Section XI Code air environment default line. The other band of data, termed 'high', resides approximately midway between the ASME Sec. XI air and water environment default lines. The two bands of data are the result of certain combinations of the waveform and temperature variables listed above, and are determined by the following rules: (1) a ramp time in excess of one second is needed to obtain the high crack growth rate; and (2) the application of a hold time, together with a high temperature, serves to depress a normally high crack growth rate test (i.e. one with a long ramp time) and force it into the low category. A hydrogen embrittlement model is used as a basis for the explanation of this behavior. During the longer ramp times (approximately one second) hydrogen, formed by aqueous hydrolysis, diffuses into the plastic zone, resulting in local embrittlement.
- Research Organization:
- Naval Research Lab., Washington, DC (USA)
- OSTI ID:
- 5572944
- Report Number(s):
- AD-A-075506
- Country of Publication:
- United States
- Language:
- English
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Fatigue-crack growth rates of A 508-2 steel in pressurized, high-temperature water. [PWR]
Hydrogen-assisted crack growth of A508-2 in high-temperature pressurized reactor-grade water
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36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHEMICAL REACTIONS
CONTAINERS
CORROSION
CRACKS
CRYOGENIC FLUIDS
DATA
ELEMENTS
EMBRITTLEMENT
EXPERIMENTAL DATA
FATIGUE
FLUIDS
FRACTOGRAPHY
HIGH TEMPERATURE
HYDROGEN
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
METALLOGRAPHY
NONMETALS
NUMERICAL DATA
PRESSURE VESSELS
PWR TYPE REACTORS
REACTORS
STEEL-ASTM-A508
STEELS
STRESS CORROSION
WATER CHEMISTRY
WATER COOLED REACTORS
WATER MODERATED REACTORS