Measuring and testing – Ductility or brittleness
Patent
1994-12-29
1996-05-21
Chilcot, Richard
Measuring and testing
Ductility or brittleness
73 86, G08B 2100
Patent
active
055178510
ABSTRACT:
An autoclave-enclosed sidestream model boiler is used to predict the onset of intergranular attack ("IGA") and stress corrosion cracking ("SCC") within tubing associated with a power generator. Power generator final feed water is fluid coupled to a pipe within the model boiler, which pipe is strain-gage monitored, preferably using welded fiber optic strain gage devices. The monitored pipe includes a crevice region that produces a water-starved region in which chemical impurities in the feed water become concentrated. A cylindrical heater, located within a portion of the monitored pipe, promotes the water-starved region. A cylindrical portion of the pipe wall preferably is thinned, generally in the region bounding the crevice. Thinning promotes the onset of IGA/SCC within the monitored pipe and also passively amplifies the effects of IGA/SCC to promote easier strain detection. To further promote stress, the monitored pipe is subjected to loading and unloading from an axial load. Drift in the strain gage measurement can be substantially eliminated by taking measurements under axial load and no load conditions, as these two conditions may be attained within a short time of each other, e.g., a few minutes. Long term monitoring of the strain gages provides a measure of onset and progression of IGA and SCC within the autoclave model. These measurements can provide a prediction of the onset of IGA and SCC within the actual power generator, allowing corrective action to be taken before a pipe fails.
REFERENCES:
patent: 3104355 (1963-09-01), Holmes et al.
patent: 3352149 (1967-11-01), Sherlock et al.
patent: 3846795 (1974-11-01), Jones
patent: 4468613 (1984-08-01), Slaugh et al.
patent: 4915473 (1990-04-01), Haese et al.
patent: 5020379 (1991-06-01), Berthold et al.
patent: 5178822 (1993-01-01), Buford III et al.
patent: 5361284 (1994-11-01), Baum et al.
Berthold John W.
Passell Thomas O.
Roman Garry W.
Biegel Ronald
Chilcot Richard
Electric Power Research Institute
Kaufman Michael A.
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