Modelling the effect of microstructural banding on the flow curve behaviour of dual-phase (DP) steels

Ramazani, Ali; Mukherjee, Krishnendu; Prahl, Ulrich; Bleck, Wolfgang

doi:10.1016/j.commatsci.2011.05.041

Cited by 137 publications

(87 citation statements)

References 17 publications

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“…The main focus of the automotive industry is to reduce the weight of car, enhance safety and crashworthiness while the cost is low [1][2][3]. In comparison with traditional low carbon and high strength low alloy steels, dual phase (DP) steels provide a combination of good formability and strength [4,5].…”

Section: Introductionmentioning

confidence: 99%

Characterization of Microstructure and Mechanical Properties of Resistance Spot Welded DP600 Steel

Ramazani

Mukherjee

Abdurakhmanov

et al. 2015

Metals

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Abstract:Resistance spot welding (RSW) as a predominant welding technique used for joining steels in automotive applications needs to be studied carefully in order to improve the mechanical properties of the spot welds. The objectives of the present work are to characterize the resistance spot weldment of DP600 sheet steels. The mechanical properties of the welded joints were evaluated using tensile-shear and cross-tensile tests. The time-temperature evolution during the welding cycle was measured. The microstructures observed in different sites of the welds were correlated to thermal history recorded by thermocouples in the corresponding areas. It was found that cracks initiated in the periphery region of weld nuggets with a martensitic microstructure and a pull-out failure mode was observed. It was also concluded that tempering during RSW was the main reason for hardness decrease in HAZ. OPEN ACCESSMetals 2015, 5 1705

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Section: Introductionmentioning

confidence: 99%

Characterization of Microstructure and Mechanical Properties of Resistance Spot Welded DP600 Steel

Ramazani

Mukherjee

Abdurakhmanov

et al. 2015

Metals

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“…The selected area of the light optical microscopy (LOM) image of the experimental microstructure was converted into a 2D RVE, taking advantage of the color difference between martensite and ferrite, using an in-house finite element generator, Gitter [32]. The smallest satisfactory dimension of the RVE in DP steels is 24 µm × 24 µm, which should contain a minimum of 19 martensite particles, as reported by Ramazani et al [16].…”

Section: Rve Generationmentioning

confidence: 99%

Low Cycle Fatigue Behaviour of DP Steels: Micromechanical Modelling vs. Validation

Moeini

Ramazani

Myslicki

et al. 2017

Metals

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Abstract:This study aims to simulate the stabilised stress-strain hysteresis loop of dual phase (DP) steel using micromechanical modelling. For this purpose, the investigation was conducted both experimentally and numerically. In the experimental part, the microstructure characterisation, monotonic tensile tests and low cycle fatigue tests were performed. In the numerical part, the representative volume element (RVE) was employed to study the effect of the DP steel microstructure of the low cycle fatigue behavior of DP steel. A dislocation-density based model was utilised to identify the tensile behavior of ferrite and martensite. Then, by establishing a correlation between the monotonic and cyclic behavior of ferrite and martensite phases, the cyclic deformation properties of single phases were estimated. Accordingly, Chaboche kinematic hardening parameters were identified from the predicted cyclic curve of individual phases in DP steel. Finally, the predicted hysteresis loop from low cycle fatigue modelling was in very good agreement with the experimental one. The stabilised hysteresis loop of DP steel can be successfully predicted using the developed approach.

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“…predict the flow-stress behavior of each phase in the steel. [11][12][13][14][15]18 The former equation represents the material strengthening due to the carbon content and other alloying elements' carbide precipitation, while the latter is based on the dislocation theory determining the effects of the grain size. 12 The approach can be expressed as Equation (1):…”

Section: Experimental Partmentioning

confidence: 99%

“…For martensite, two constants, 41 and 0.038, were used to define k and L. 11,13,15,18 The second term is the solid-solution strengthening due to the carbon and nitrogen contents. …”

Section: Recentlymentioning

confidence: 99%

“…9,10 Recently, researchers obtained the flow curves of the composite phases using micromechanical modelling based on the RVEs selected from a real microstructure. [11][12][13][14][15][16][17][18][19] The flow behavior of a DP steel mainly depends on the properties of ferrite and martensite and the volume fractions of different phases. As steel has the same chemical composition, when modelling heat-treated steels, the model mainly focuses on the effects of strengthening methods and the grain size on the strength of different phases.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phase-transformation behavior and micromechanical properties of a dual-phase steel after chemical modifications

Zhao¹,

Zhao²,

Sun³

et al. 2017

Mater. Tehnol.

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In this work, the phase-transformation behavior and micromechanical properties of a dual-phase steel after chemical modifications were investigated theoretically and experimentally. In particular, the micromechanical behavior of the steel was modeled, based on the effects of the microstructure, phase fractions, local compositions of single phases and their area shapes. The developed model was used for predicting the damage behavior of a specimen. It was demonstrated that the tensile strength increased with the increasing temperature due to an increase in the amount of martensite in the steel, but the hardening behavior of this specimen was affected by the microstructure. Furthermore, the flow curves of the steel under different intercritical temperatures could be well predicted based on the real microstructures. The subsequent simulation results showed that while higher stress concentrated on the martensite, the shear-band appearance strongly depended on the microstructures of the phases. In addition, for the prediction of damage behaviors, the true stress/true strain curves of macroscale simulations showed good agreement with the experiments involving differently heat-treated steels. Keywords: intercritical treatment, steel, micro model V tem delu so teoreti~no in eksperimentalno preiskovali fazne spremembe in mikromehanske lastnosti dvofaznega jekla po kemijskih prilagoditvah. [e posebej je bilo modelirano mikromehansko obna{anje jekla glede na mikrostrukturo, dele`e posameznih faz, lokalno sestavo posameznih faz in njihovo morfologijo. Razviti model je bil uporabljen za napoved po{kodb vzorca. Dokazano je bilo, da se natezna trdnost pove~uje z nara{~ajo~o temperaturo zaradi nara{~anja vsebnosti martenzita v jeklu, vendar je na kaljivost tega vzorca vplivala mikrostruktura. Nadalje je bilo ugotovljeno, da je mo`no krivulje te~enja jekla pri razli~nih interkriti~nih temperaturah dobro napovedati na podlagi dejanskih mikrostruktur. Nadalje so rezultati simulacij pokazali, da so vi{je napetosti koncentrirane na martenzitu in isto~asna prisotnost stri`nih pasov, mo~no odvisne od mikrostruktur posameznih faz. Poleg tega je za napoved po{kodb pomembno, da se prave krivulje napetost-deformacija, dobljene s pomo~jo simulacij na makronivoju, dobro ujemajo z eksperimentalnimi, dobljenimi pri razli~no toplotno obdelanih jeklih.

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Modelling the effect of microstructural banding on the flow curve behaviour of dual-phase (DP) steels

Cited by 137 publications

References 17 publications

Characterization of Microstructure and Mechanical Properties of Resistance Spot Welded DP600 Steel

Characterization of Microstructure and Mechanical Properties of Resistance Spot Welded DP600 Steel

Low Cycle Fatigue Behaviour of DP Steels: Micromechanical Modelling vs. Validation

Phase-transformation behavior and micromechanical properties of a dual-phase steel after chemical modifications

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