M. Pardun et al., APPLICATION OF A MICROMECHANICAL DAMAGE MODEL TO THE ANALYSIS OF DUCTILE FRACTURE OF A THERMOMECHANICALLY TREATED STEEL WITH DIFFERENT MICROSTRUCTURES, Steel research, 68(6), 1997, pp. 272-276
A possibility to characterize the different stages of the process of d
uctile fracture from a more microscopic point of view are micromechani
cal damage models, On a steel 27MnSiVS6 microalloyed additionally with
titanium, which belongs to the group of the microalloyed precipitatio
n hardening ferritic-pearlitic steels, different states of microstruct
ure (ferrite-pearlite, tempered martensite, bainite) were produced usi
ng thermomechanical treatment. On such specimens fracture mechanics te
sts were done with side-grooved 1/2 CT-specimens and the results were
compared with those obtained by a numerical simulation based on the mo
dified Gurson model. A good agreement between calculated and measured
J(R)-curves also for a thermomechanical treated steel with separations
was found. The critical distance l(c) has a great influence on the re
sults of this numerical model. A qualitative relation between this par
ameter and the average inclusion spacing, which depends on the microst
ructure, was found.