Assistant professor, Tennessee Technological University, Cookeville, TN
Professor, The University of Tennessee, Knoxville, TN
Pages: 13 Published: Jan 2000
The notched round bar (NRB) geometry was assessed for use with ASTM E 1921-97 Standard for Test Method for the Determination of Reference Temperature, T0, for Ferritic Steels in the Transition Range. Instead of precracking the NRB specimens, apparent fracture toughness using three different notch root radii was extrapolated to a zero radius to infer sharp crack fracture toughness. The reference temperature using A302B NRB specimens was determined to be -89°C, while A302B C(T) specimens yield T0 of -87.3°C. In applying ASTM E 1921 to the NRB geometry, a simple scheme to remove notch root radius bias from apparent fracture toughness was developed. In addition, a size correction for converting NRB results to comparable 1T-C(T) results was investigated.
notched round bars (NRB), A302B steel, transition fracture toughness
Paper ID: STP14806S