Quantification of Specimen Geometry Effects on the Master Curve and To Reference Temperature
Type: article
Abstract: Application of the Master Curve method and associated reference temperature of ASTM E1921 to define the ductile to brittle transition in ferritic structural steels used in commercial nuclear reactor vessels requires extensive experimental verification.Recent suggestions have proposed replacing the nil-ductility reference temperature RT NDT of the ASME Boiler and Pressure Vessel Code with a RT To reference temperature.This reference temperature could then be used to position the median and lower bound transition toughness curves for the purpose of thermal shock evaluations or for life extension of existing US commercial nuclear power stations.In this experimental program different C(T), SE(B), and pre-cracked Charpy specimen geometries have been investigated including both deep and shallow cracked SE(B) geometries.Two or more test temperatures were used for each geometry and at least 6 identical specimens of each specimen configuration have been tested at each temperature.Specimen geometries have ranged from 5 mm thick SE(B) specimens to standard 1T (25mm by 50 mm) three point bend specimens and crack length to specimen width ratios for the SE(B) specimens ranged from a/W = 0.12 to 0.6.The material utilized was an A533 Grade B steel obtained from the decommissioned Shoreham nuclear power plant pressure vessel.Three distinct populations of data appear to exist in the results of this program corresponding to C(T) specimens, SE(B) specimens, and shallow crack SE(B) specimens.The differences found between shallow and deep crack specimens is not surprising, but the magnitude of the differences found between the C(T) and deep crack SE(B) specimens was highly unexpected and does not appear to have been previously reported.
Authors: J. A. Joyce, R. L. Tregoning
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1961726415