Predicting Fracture Toughness of TRIP 800 Using Phase Properties Characterized by In-Situ High-Energy X-Ray Diffraction

Abstract

Transformation-induced plasticity (TRIP) steel is a typical representative of first generation advanced high-strength steel, which exhibits a combination of high strength and excellent ductility due to its multiphase microstructure. In this article, we study the crack propagation behavior and fracture resistance of a TRIP 800 steel using a microstructure-based finite element method with the various phase properties characterized by in-situ high-energy X-ray diffraction (HEXRD) technique. Uniaxial tensile tests on the notched TRIP 800 sheet specimens were also conducted, and the experimentally measured tensile properties and R curves (resistance curves) were used to calibrate the modeling parameters and to validate the overall modeling results. The comparison between the simulated and experimentally measured results suggests that the micromechanics based modeling procedure can well capture the overall complex crack propagation behaviors and the fracture resistance of TRIP steels. The methodology adopted here may be used to estimate the fracture resistance of various multiphase materials.

Plastic deformation and damage induced by fatigue in TWIP steels

“…Thus, the grain size and crystallographic orientation play a significant role in the thickness of the deformation twins. This agrees with the data reported by Soulami et al [46].…”

“…Therefore, over a distance of 15 m (grains 1 and 7), the cumulated misorientation reaches a value higher than 60º. Several fundamental mechanisms for mechanical twinning in fcc materials are proposed in the literature [46], probably due to the heterogeneous character of the observations. Furthermore, as it can be observed from the profiles, the twin thickness is different from one grain to another.…”

Extreme shear-deformation-induced modification of defect structures and hierarchical microstructure in an Al–Si alloy

“…2b). A 2-D, microstructure-based finite element reciprocating shear deformation model 50,51 was also employed to analyze stress and plastic strain accumulation in the microstructure and to simulate the von Mises stress distribution and equivalent plastic strain after three cycles of reciprocal shear deformation.…”

Micromechanics of plastic deformation and phase transformation in a three-phase TRIP-assisted advanced high strength steel: Experiments and modeling

“…The phases were modeled using constitutive relations developed for austenitic steels or shape memory alloys Tjahjanto et al, 2006;Sierra and Nemes, 2008). Efforts have also been made towards microstructure based modeling using 2-D idealization of the microstructure and assuming simple elastic-plastic constitutive relations with isotropic hardening for each phase together with a phenomenological description of phase transformation Soulami et al, 2010).…”

“…Determining accurate values for the properties of the phases has been a significant challenge. A common approach has been to select parameters to fit the macroscopic flow response (Perlade et al, 2003;Han et al, 2009) or to fit the parameters to match the lattice strain measured using neutron or X-ray diffraction techniques Delannay et al, 2008;Choi et al, 2009;Soulami et al, 2010). These experiments probe the collective behavior of the overall microstructure and therefore, extracting material properties from the data is not straightforward.…”