Ductile crack initiation in steels

RETRACTED: Modeling Ductile-to-Brittle Transition Temperature of Functionally Graded Steels by Gene Expression Programming

“…However, the mechanism of the formation of microvoids and their special distribution ahead of the crack tip may be different. Recently, Ebrahimi and Seo (1996) have investigated crack initiations in two specific types of steels: a ferritic-pearlitic and a bainitic structural steel. In the ferritic-pearlitic steel, relatively large inclusions, mainly manganese sulfide, were found close to the crack tip, where microvoids may form due to high shear stresses; ductile cracks usually grow along the position of these particles.…”

RETRACTED: Ductile to Brittle Transition Temperature of Functionally Graded Steels

“…However, the mechanisms of the formation of microvoids and their special distribution ahead of the crack tip may be different. Recently, Ebrahimi and Seo (1996) have investigated crack initiations in two specific type of steels: a ferriticpearlitic and a bainitic structural steel. In the ferriticpearlitic steel, relatively large inclusions, mainly manganese sulfide, were found to be close to the crack tip, where microvoids may form due to high shear stresses, and ductile cracks usually grow along the position of these particles.…”

Experimental investigation on ductile stable crack growth emanating from wire-cut notch in AISI 4340 steel

“…In the second stage predictions based on the trial criterion are verified by experiment. Some of the candidate criteria, that are considered, are the contour integral J (Narasimhan et al, 1992), crack opening displacement COD (Ma et al, 1999(Ma et al, , 2001, crack opening angle COA and crack tip opening angle CTOA (Newman, 1984;Mourad, 1995a, 1995b;Mourad and Maiti, 1996), stretch zone width (Otsuka et al, 1974(Otsuka et al, , 1976(Otsuka et al, , 1977Ebrahimi and Seo, 1996) and local energy criterion (Tvergaard and Hutchinson, 1992). In the micromechanics approach the ductile fracture mechanism is studied through void/damage nucleation and growth model.…”