In-situ observation of strain partitioning and damage development in continuously cooled carbide-free bainitic steels using micro digital image correlation

Kumar, Ankit; Dutta, Aniruddha; Makineni, Surendra Kumar; Herbig, Michael; Petrov, Roumen; Sietsma, Jilt

doi:10.1016/j.msea.2019.04.098

Cited by 68 publications

(37 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, the BRA islands in B360-HT will partially transform into martensite during the tensile fracture and small BRA islands (<250 nm), and TFRA would be stable during the tensile fracture. The mechanical stability of the small BRA islands is governed by the C enrichment in these islands due to high bainitic ferrite fraction [54,55]. Furthermore, thin film retained austenite (TFRA) in this steel is even more mechanically stable than BRA due to constraints from bainitic ferrite, high defect density in the TFRA due to displacive bainitic transformation and high C enrichment (up to 8 at.…”

Section: B360 Gradementioning

confidence: 99%

See 1 more Smart Citation

Influence of Microstructure on Mechanical Properties of Bainitic Steels in Railway Applications

Hajizad

Kumar

et al. 2019

Metals

View full text Add to dashboard Cite

Wheel–rail contact creates high stresses in both rails and wheels, which can lead to different damage, such as plastic deformation, wear and rolling contact fatigue (RCF). It is important to use high-quality steels that are resistant to these damages. Mechanical properties and failure of steels are determined by various microstructural features, such as grain size, phase fraction, as well as spatial distribution and morphology of these phases in the microstructure. To quantify the mechanical behavior of bainitic rail steels, uniaxial tensile experiments and hardness measurements were performed. In order to characterize the influence of microstructure on the mechanical behavior, various microscopy techniques, such as light optical microscopy (LOM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), were used. Three bainitic grades industrially known as B360, B1400 plus and Cr-Bainitic together with commonly used R350HT pearlitic grade were studied. Influence of isothermal bainitic heat treatment on the microstructure and mechanical properties of the bainitic grades was investigated and compared with B360, B1400 plus, Cr-Bainitic and R350HT in as-received (AR) condition from the industry. The results show that the carbide-free bainitic steel (B360) after an isothermal heat treatment offers the best mechanical performance among these steels due to a very fine, carbide-free bainitic microstructure consisting of bainitic ferrite and retained austenite laths.

show abstract

Section: B360 Gradementioning

confidence: 99%

“…It was shown that in B360-AR bainitic steel, micro-cracks initiate primarily at the weak interfaces between martensite and bainitic ferrite. [55][56][57]. Figure 9a shows superimposed Image Quality (IQ) and phase maps of the B360-HT steel.…”

Section: B360 Gradementioning

confidence: 99%

Influence of Microstructure on Mechanical Properties of Bainitic Steels in Railway Applications

Hajizad

Kumar

et al. 2019

Metals

View full text Add to dashboard Cite

show abstract

“…Using the commercial ABAQUS/ Explicit software (ABAQUS 6.11-1), a 2-D finite element model (FEM) with 200 × 200 random elements was set up for uniaxial tension. Based on the experimental measurements (Kumar et al, 2019), the following boundary conditions are used in the proposed FEM. The displacement along x direction at the top boundary is the same as that at the bottom boundary.…”

Section: Multiple Microstructuresmentioning

confidence: 99%

Hierarchical-microstructure based modeling for plastic deformation of partial recrystallized copper

Liu

Cai

et al. 2019

Mechanics of Materials

View full text Add to dashboard Cite

Hierarchical microstructure in partial recrystallized materials can simultaneously improve the strength and ductility of metallic materials. Modeling the mechanical behavior of partial recrystallized materials helps to process materials with superior combination of ductility and strength. Here, using experimental characterization, cellular automation (CA) and finite element method, hierarchical-microstructure based modeling was proposed to simulate the tensile deformation of partial recrystallized copper. Firstly, partial recrystallized coppers with different volume fractions of recrystallization were produced by means of extrusion machining and subsequent heat treatment (HT). Uniaxial tensile tests and microstructural observations show that the hierarchical-microstructure of recrystallized grains (RGs) surrounded by elongated subgrains has a significant effect on the mechanical properties. Then, based on the experimental results, a hierarchical-microstructure based plasticity model was developed to describe the yield surface of partial recrystallized materials. CA was further employed to simulate the hierarchical microstructure. By embedding the plasticity model and simulated hierarchical-microstructure in finite element method, a finite element model (FEM) for mechanical behavior of partial recrystallized copper was proposed, where the elongated subgrain with forest dislocation and low angle grain boundary, the RG with few dislocations and twin boundary, and volume fraction of recrystallization were taken into consideration. Finally, the experimental data and the comparison with the conventional plasticity model validate the rationality of the proposed model.

show abstract

“…Pearlitic steel has been widely used in railway system, but the conventional pearlitic steel is susceptible to the formation of various defects, such as head checks and corrugation under actual rail-wheel contact conditions, which may lead to rail fracture and consume a great deal of maintenance cost and time [ 1 , 2 , 3 ]. Compared with traditional pearlitic steel, even though the welding of bainitic rail steel may lead to the appearance of high-carbon martensite, which is bad for the quality of welded joint, the technique of post-weld heat treatment has been conducted to solve this problem.…”

Section: Introductionmentioning

confidence: 99%

Dry Rolling/Sliding Wear of Bainitic Rail Steels under Different Contact Stresses and Slip Ratios

Liu

Zhang

et al. 2020

Materials

View full text Add to dashboard Cite

This study aims to deeply understand the effect of contact stress and slip ratio on wear performances of bainitic rail steels. The results showed that the wear loss increased as the contact stress and slip ratio increased. Based on the surface damage morphology and microstructural analyses, it revealed that the rolling contact fatigue wear mechanism played a significant role under the low slip ratio, but the dominant wear mechanism transferred to the abrasive wear at the high slip ratio. Meanwhile, the bainitic steel specifically presented worse wear resistance under the abrasive wear mode. Compared with the influence of a slip ratio, the increase in contact stress led to severer plastic flows and contributed to the propagation of cracks. In addition, the contact stress and slip ratio had the opposite effect on the friction coefficient, that is, the friction coefficient of bainitic steels behaved the inverse proportion with the contact stress, but positive proportion with the slip ratio. At last, the increase in slip ratio had more significant effect on the reduction of retained austenite (RA) than the enlargement of contact stress due to the fact that the RA would probably be removed before the martensitic transformation occurred under the abrasive wear mechanism.

show abstract

In-situ observation of strain partitioning and damage development in continuously cooled carbide-free bainitic steels using micro digital image correlation

Cited by 68 publications

References 61 publications

Influence of Microstructure on Mechanical Properties of Bainitic Steels in Railway Applications

Influence of Microstructure on Mechanical Properties of Bainitic Steels in Railway Applications

Hierarchical-microstructure based modeling for plastic deformation of partial recrystallized copper

Dry Rolling/Sliding Wear of Bainitic Rail Steels under Different Contact Stresses and Slip Ratios

Contact Info

Product

Resources

About