Mechanisms of void formation during tensile testing in a commercial, dual-phase steel

• Published in: Acta materialia Vol. 59; no. 7; pp. 2575 - 2588
• Main Authors: Kadkhodapour, J., Butz, A., Ziaei Rad, S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-04-2011
• Subjects: Dual phase steels; Dual-phase (DP) steel; Duplex stainless steels; Failure mechanism; Failure mechanisms; Martensite; Martensite shape effect; Mathematical models; Nucleation; Steels; Tensile test; Void initiation; Voids; Failure mechanism; Void initiation; Dual-phase (DP) steel; Martensite shape effect; Tensile test
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2010.12.039

A detailed analysis of the microstructure and failure mechanism of a dual-phase steel material as a function of strain was conducted. Accordingly, three tensile tests were performed and interrupted at different strain levels in order to investigate void nucleation, void growth and void coalescence. Scanning electron microscopy analysis revealed that void nucleation occurs by ferrite grain-boundary decohesion in the neighborhood of martensite grains. Further, void initiation could be observed between closely situated martensite grains. Martensite morphology and distribution has a significant impact on the accumulation of damage. The mechanism of failure was found to be influenced by deformation localization due to microstructural inhomogeneity. Based on the experimental observations and simulation results, a model describing the failure mechanism is proposed for dual-phase steel material.