Quantitative Fractographic Analysis of Variability in the Tensile Ductility of a High Strength Dual-Phase Steel

Abstract

Variability in tensile ductility of a dual-phase steel is investigated using quantitative microscopy and fractography. Variability in the ductility does not correlate with the global properties such as phase volume fractions. Quantitative fractography reveals an inverse quantitative correlation between number density of the pullouts of ferrite-martensite colonies in the fracture surfaces and the ductility of corresponding tensile test specimens. Therefore, local variations in the attributes of interfaces, rather than global microstructural properties, account for a significant part of variability in ductility. © 2012 Springer Science+Business Media New York and ASM International.