PRAKTISCHE METALOGRAPHIE, cilt.42, sa.2005, ss.290-303, 2005 (SCI-Expanded)
The present article is intended to examine the relationships between the microstructure and
the fracture mechanical properties. It uses the J integral concept for a characterization of the
properties of fracture mechanics. The microalloyed steels of the X65/API-5L type were used
for this purpose. Some of the individual microstructures were characterized qualitatively,
others quantitatively, by means of a light microscope (LM) and a scanning electron
microscope (SEM). The examinations of the size and distribution of the non-metallic