Senior scientific officer, Risley Nuclear Laboratories, Warrington, Cheshire
Pages: 21 Published: Jan 1985
The paper outlines the problems encountered in attempting to define a self-consistent upper shelf toughness data base for use in a generic study of the integrity of a light water reactor (LWR) pressure vessel. Multiple-specimen resistance curve JR data were examined to provide “best estimates” of static initiation fracture toughness Ki at temperatures corresponding to fully ductile upper shelf behavior. In some cases, this involved reassessment of published data. To provide information that should be typical of current commercial steel making practice, Ki temperature relationships were developed from a statistical analysis of those data for A533B-1 and A508-3 steels containing less than 0.010 weight % sufur.
Relatively few data exist for weld metals, but the available results indicated that the Ki temperature relationships derived for base metals should also be applicable when assessing the significance of defects located in welds of a modern LWR pressure vessel.
Lower bound slopes (dJ/da)LB to the available JR data for A533B-1 and A508-3 steels were also defined. These can be used in conjunction with the Ki temperature relationships to derive post-initiation toughness data for up to 2-mm crack growth. The data base was derived from linear JR analyses, and its relevance to upper shelf initiation toughness data derived from nonlinear (power law) JR analyses is considered. Different methods of estimating initiation toughness are discussed and proposals are made to simplify the interpretation of upper shelf toughness data.
ductility, crack propagation, temperature, welded joints, sulfur, upper shelf, fracture toughness (initiation), J, R, curve, pressure vessel steels
Paper ID: STP34517S