Characterization and Modeling of Failure Initiation in Bainite‐Aided DP Steel

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.

show abstract

“…The variables were deducted from Rodriguez [34] and Ramazani et al [40,41] and are given in Table 3. …”

Section: Single Phase Flow Curve Modellingmentioning

confidence: 99%

“…The variables were deducted from Rodriguez [34] and Ramazani et al [40,41] and are given in Table 3. The carbon content of ferrite (C f ss ) was approximated using the ThermoCalc software (Thermo-Calc Software, Solna, Sweden) with the TCFe6 database.…”

Section: Single Phase Flow Curve Modellingmentioning

confidence: 99%

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

Moeini

Ramazani

Myslicki

et al. 2017

Metals

Self Cite

View full text Add to dashboard Cite

show abstract

“…journal.ump.edu.my/ijame ◄ (XFEM) is often used due to its advantages, like the capability of allowing the crack propagation through the elements without the need of remeshing after each time step, reducing the computation cost [19]. Different researches use the XFEM method to evaluate crack propagation in metals to evaluate fatigue and fracture under static loads cases [20][21][22], and specifically on dual-phase steels [23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Fatigue Crack Growth and Fracture Toughness in a Dual Phase Steel: Effect of Increasing Martensite Volume Fraction

Velasquez¹,

Rodríguez²,

Tovar³

et al. 2020

IJAME

View full text Add to dashboard Cite

Crack growth resistance in dual-phase steel was studied. The dual phase steel microstructure was modified through heat treatments to increase the martensite volume fraction from 10% to 40%. The as-received and heat-treated samples were evaluated using a uniaxial tensile test, fatigue crack growth test, and fracture toughness test. Extended Finite Element Method (XFEM) was used to simulate the crack growth in compact tension test specimens. The results showed that an increase in martensite volume fraction is an effective way to increase the fracture resistance under different load conditions, quasistatics and dynamic, increasing the fracture toughness, tensile strength and fatigue resistance of the heat-treated material. Presence of a highest content of martensite results in formation of an important number of secondary cracks during the fatigue crack growth, which slow down the crack propagation. Moreover, martensite generates a crack closure over the crack tip, making the propagation difficult due to the irregularities caused by the crack growth on the martensite. Finally, the computational load-displacement curves are in good agreement with the experimental data.

show abstract

“…DP steels are produced by controlled cooling of specimen from the austenite phase or the two‐phase range (ferrite + austenite) to transform some austenite to ferrite. In the following, the specimens are quenched to transform the remaining austenite to martensite . DP steels have a high ultimate tensile strength, combined with a low initial yielding stress, and high early stage strain hardening and macroscopically homogeneous plastic flow .…”

Section: Introductionmentioning

confidence: 99%

The Effect of Bake-Hardening Parameters on the Mechanical Properties of Dual-Phase Steels

Ramazani

Bruehl

Abbasi

et al. 2016

steel research int.

Self Cite

View full text Add to dashboard Cite

Dual-phase (DP) steels offer an outstanding combination of strength and formability as a result of their microstructure, in which a hard martensitic or bainitic phase is dispersed in a soft ferritic matrix. DP steels have a high ultimate tensile strength combined with a low initial yielding stress. The yield strength of DP steels is further increased by the paint baking, also called bake hardening (BH), process. In the current research, the effect of BH parameters, namely pre-strain, baking temperature, and holding time, on yield strength increment of DP steels with different martensite volume fractions is investigated. DP steels with 20 and 30% martensite volume fraction are pre-strained up to 5%, then they are baked at 100, 170, and 300 8C for various times. The results show that maximum yield strength is obtained as optimum values of BH parameters are applied. It is also found that at high values of baking temperature and holding time, martensite tempering effects prevail and yield strength increment decreases. The results also indicate that the increment of pre-strain enhances the Lüders band and decreases the yield strength increment.

show abstract

Characterization and Modeling of Failure Initiation in Bainite‐Aided DP Steel

Cited by 20 publications

References 50 publications

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

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

Fatigue Crack Growth and Fracture Toughness in a Dual Phase Steel: Effect of Increasing Martensite Volume Fraction

The Effect of Bake-Hardening Parameters on the Mechanical Properties of Dual-Phase Steels

Contact Info

Product

Resources

About