PSI - Issue 42

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ScienceDirect

Procedia Structural Integrity 42 (2022) 1651–1659 Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 0 ( 0 9) 000–000

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© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 2020 The Authors. Published by Elsevier B.V. his is an open access article under the CC BY-NC-ND license (http://creativec mmons.org/licenses/by-nc-nd/4.0/) eer-review under responsibility of 23 European Conference on Fracture – ECF23 . Keywords: Dual-phase steel; Crystal Plasticity; Cohesive Zone Elements; Ductile Failure Abstract Ferrite-martensite dual-phase (DP) steels have become popular in weight-reduced automotive components due to their straightfor ward thermomechanical processing and excellent mechanical properties. Even though it has been a popular and productive area of research, there are still many open questions related to their interesting microstructure. Being composed of brittle martensitic clusters dispersed in a ductile ferrite matrix, DP steels benefit from the properties of both phases, which induce interesting fail ure mechanisms at the same time. The microstructural parameters such as martensite volume fraction, grain size, carbon content, martensite/ferrite morphology, ferrite grain size, and texture, as well as micro and mesoscale segregation, make them difficult to analyze. However these aspects have to be studied in order to link the underlying microstructural influence to macroscopic be haviour. Therefore, the modelling techniques at the microstructure scale should be utilized for physical understanding. In this work, a multi scale odeling strategy is followed for the analysis of plastic deformation and failure in DP steels. A rate-dependent crystal plasticity framework and the isotropic J 2 plasticity model are employed for the simulation of the plastic deformation in ductile ferrite phase and in the hard martensite phase respectively at the RVE scale. Moreover, the intergranular cracking is studied by the incorporation of a cohesive zone model at the ferrite-martensite grain boundaries and the failure in martensite phase is addressed through a ductile failure model. The effect of microstructural parameters on both plastic and fracture behaviour is analyzed under axial loading conditions. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture – ECF23 . Keywords: Dual-phase steel; Crystal Plasticity; Cohesive Zone Elements; Ductile Failure 23 European Conference on Fracture – ECF23 Crack Initiation and Propagation in Dual-phase Steels Through Crystal Plasticity and Cohesive Zone Frameworks Tuncay Yalc¸inkaya a, ∗ , Berkehan Tatli a , Izzet Erkin U¨ nsal a , Ilbilge Umay Aydiner a a Department of Aerospace Engineering, Middle East Technical University, 06800, Ankara, Turkey Abstract Ferrite-martensite dual-phase (DP) steels have become popular in weight-reduced automotive components due to their straightfor ward thermomechanical processing and excellent mechanical properties. Even though it has been a popular and productive area of research, there are still many open questions related to their interesting microstructure. Being composed of brittle martensitic clusters dispersed in a ductile ferrite matrix, DP steels benefit from the properties of both phases, which induce interesting fail ure mechanisms at the same time. The microstructural parameters such as martensite volume fraction, grain size, carbon content, martensite/ferrite morphology, ferrite grain size, and texture, as well as micro and mesoscale segregation, make them difficult to analyze. However these aspects have to be studied in order to link the underlying microstructural influence to macroscopic be haviour. Therefore, the modelling techniques at the microstructure scale should be utilized for physical understanding. In this work, a multi scale modeling strategy is followed for the analysis of plastic deformation and failure in DP steels. A rate-dependent crystal plasticity framework and the isotropic J 2 plasticity model are employed for the simulation of the plastic deformation in ductile ferrite phase and in the hard martensite phase respectively at the RVE scale. Moreover, the intergranular cracking is studied by the incorporation of a cohesive zone model at the ferrite-martensite grain boundaries and the failure in martensite phase is addressed through a ductile failure model. The effect of microstructural parameters on both plastic and fracture behaviour is analyzed under axial loading conditions. 23 European Conference on Fracture – ECF23 Crack Initiation and Propagation in Dual-phase Steels Through Crystal Plasticity and Cohesive Zone Frameworks Tuncay Yalc¸inkaya a, ∗ , Berkehan Tatli a , Izzet Erkin U¨ nsal a , Ilbilge Umay Aydiner a a Department of Aerospace Engineering, Middle East Technical University, 06800, Ankara, Turkey

1. Introduction 1. Introduction

The quest for light metals lead to the development of advanced high-strength steels in the automotive industry among which ferrite–martensite dual-phase (DP) steels have a prominent place with various advantages (see Tasan et al. (2015) for an overview). Composed of a hard martensite phase embedded in a soft ferrite matrix, DP steel has a composite microstructure presenting attractive mechanical properties such as high strength, high initial strain The quest for light metals lead to the development of advanced high-strength steels in the automotive industry among which ferrite–martensite dual-phase (DP) steels have a prominent place with various advantages (see Tasan et al. (2015) for an overview). Composed of a hard martensite phase embedded in a soft ferrite matrix, DP steel has a composite microstructure presenting attractive mechanical properties such as high strength, high initial strain

∗ Corresponding author. Tel.: +903122104258 ; fax: +903122104250. E-mail address: yalcinka@metu.edu.tr ∗ Corresponding author. Tel.: +903122104258 ; fax: +903122104250. E-mail address: yalcinka@metu.edu.tr

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.208 2210-7843 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture – ECF23 . 2210-7843 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture – ECF23 .