ABSTRACT
Methods to determine fracture toughness of structural materials as documented in
ASTM standard E-1820 are neither appropriate for quality control of tonnage materials
at the stage of production due to techno-economic reasons nor are suitable for material
development owing to their time-consuming nature. This report aims to suggest a
common solution to these problems considering measurement of fracture toughness
(KIVM) using chevron notched bend bar specimens with either rectangular cross-section
(RC) or circular cross-section (CC). The theoretical background for obtaining KIVMRC
and KIVMCC and the corresponding normalized stress intensity factors are first discussed
in this report. The usefulness of this technique is next illustrated using a number of
examples related to the examinations of the (a) effect of inclusions on toughness
characteristics of microalloyed steels, (b) optimization of the volume fraction of the
constituent phases in dual phase steels, (c) design of heat treatment for cast rolls and
(d) designing small specimens for fracture toughness determination.