ESTIMATION OF LOWER BOUND FRACTURE RESISTANCE OF PRESSURE VESSEL STEEL IN THE TRANSITION REGIME

Abstract

Abstract— An empirical investigation of different procedures was carried out for determining a lower bound fracture toughness on the basis of small specimen test data in the ductile‐to‐brittle transition range. The procedures have been applied to various data sets in order to study the practicability and behaviour of the different procedures.It has been shown that these procedures produce estimates which fall into the lower tail regime of the scatter band of fracture toughness. Within the range of the data sets investigated these estimated lower bounds do not significantly depend on the specimen size, side grooving of the specimens and the magnitude of the data set used for the estimation. Nevertheless, the estimated lower bound values themselves are different depending on the method used for the estimation.