Topology of grain deformation

Singh, S. B.; Bhadeshia, H. K. D. H.

doi:10.1179/mst.1998.14.8.832

Cited by 37 publications

(15 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is an interesting aspect which has never before been explored, i.e., the creation of a pancaked austenite grain structure, especially in the rail-head. Pancaking would lead to a dramatic increase in the amount of grain surface per unit volume because of the highly anisotropic grain shape [35] and hence a more pronounced reduction inL γ than if equiaxed grains are made finer. Similarly, there is the possibility of further refinement due to shear band formation in unrecrystallised austenite.…”

Section: Austenite Grain Structure In Rail Steelsmentioning

confidence: 99%

“…In the context of axisymmetric compression of tetrakaidecahedron shape of grains (Figure 8.6), the effect of plastic deformation on the austenite grain boundary per unit volume in the last deformation pass can be analysed using equations 8.2 and 8.3. Equation 8.2 is derived by applying homogeneous deformations to tetrakaidecahedra in a variety of orientations and the equation 8.3 is by using the principles of stereology [35,152].…”

Section: Topology Of Austenite Grain Deformationmentioning

confidence: 99%

“…So the experimental S V /S V 0 can be calculated from the mean linear intercept measurement of the austenite grain sizes as [35,152]:…”

Section: Topology Of Austenite Grain Deformationmentioning

confidence: 99%

See 2 more Smart Citations

Niobium in Microalloyed Rail Steels

Ray

Bhadeshia

2015

HSLA Steels 2015, Microalloying 2015 &Amp; Offshore Engineering Steels 2015

Self Cite

View full text Add to dashboard Cite

Rail steels rely primarily on possessing adequate wear and rolling contact fatigue resistance. These properties, together with the toughness, can in principle be optimized by implementing thermomechanical processing assisted by controlled niobium additions. The purpose of the current work is to develop a Nb-microalloying strategy in the context of high-carbon pearlitic and cementite-free bainitic steels. The conventional methods do not leave the critical regions of a rail section in a suitably processed state. An attempt has been made for the first time, to create a pancaked austenite grain structure, with an examination of the consequences on the final Declaration This dissertation is submitted for the degree of Doctor of Philosophy at the University of Cambridge. The research reported was conducted under the supervision of

show abstract

Section: Austenite Grain Structure In Rail Steelsmentioning

confidence: 99%

Section: Topology Of Austenite Grain Deformationmentioning

confidence: 99%

See 1 more Smart Citation

Niobium in Microalloyed Rail Steels

Ray

Bhadeshia

2015

HSLA Steels 2015, Microalloying 2015 &Amp; Offshore Engineering Steels 2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…The thickness of bainite subunit is typically about 0.2 µm [1], although it does depend on the strength of austenite and the driving force accompanying the transformation [39]. However, for the present purposes we assumed, thickness w α = 0.2 µm to calculate the decarburisation time.…”

Section: Fe-c Binary Systemmentioning

confidence: 99%

Modelling of transition from upper to lower bainite in multi-component system

Guo

Roelofs

Lembke³

et al. 2016

Materials Science and Technology

View full text Add to dashboard Cite

A model for estimating the upper to lower bainite transition has been developed for the iron-carbon-manganese-chromium-silicon alloy system by comparing the time required to decarburise a supersaturated bainitic ferrite platelet and that needed for the start of cementite precipitation in the ferrite. The problem is treated as a competition between the decarburisation time and the kinetics of cementite precipitation. Lower bainite is induced when the latter process is faster. The time for forming a volume fraction of 0.01 of the equilibrium amount of cementite is taken as the precipitation start time. The model was calibrated using experimental data from iron-carbon system, and verified with iron-carbon-manganese-molybdenum system and an experimental steel currently being developed for high-strength applications.

show abstract

“…Modelling of single crystal plasticity by numerical methods allows discussion of deviations of experimental results from ideal crystal behavior [17][18][19]. Information about the change of the grain surface area per unit volume as a function of deformation parameters is important in the production of steels [20].The amount of grain surface and grain edge per unit volume are parameters important in kinetic theory since both of them are heterogeneous nucleation sites. Recently published works demonstrate that problems of geometrical orientation of structure and distortion of structural units induced by deformation play an important role in different areas.…”

Section: Introductionmentioning

confidence: 99%

On the Applicability of Stereological Methods for the Modelling of a Local Plastic Deformation in Grained Structure: Mathematical Principles

Minárik

Martinkovič

2020

Crystals

View full text Add to dashboard Cite

Analysis of systems and structures from their cross-sectional images finds applications in many branches. Therefore, the question of content, quantity, and accuracy of information obtained from various techniques based on cross-sectional views of structures is particularly important. Application of conventional techniques for two-dimensional imaging on the analysis of structure from a cross-sectional image is limited. The reason for this limitation is the fact that these techniques use a fixed cross-sectional plane and therefore cannot check the 3D structural changes caused by deformation. Geometric orientation of a grained structure must be considered when data, scanned from a cross section, is processed in order to obtain information about local deformation in this structure. The so-called degree of structure orientation in 3D can be estimated experimentally from the cross-sectional image of the structure by the statistical (Saltykov) method of oriented testing lines. Subsequently if the correlation between orientation and deformation were to be known a detailed map of local deformation in the structure could be revealed. Unfortunately, exact theoretical works dealing with the assessment of local deformation by means of change of structure orientation in 3D are still missing. Our work seeks to partially remove this shortcoming. In our work we are interested in how the transformation of the image of a grained structure in a cross-sectional plane reflects structure deformation. An initial shape of grains is assumed which is transformed into a deformed shape by analytic calculation. We present brief mathematical derivations aimed at the problem of single grain-surface area deformation. The main goal of this work led to the design of a computationally low consuming procedure for quantification of local deformation in a grained structure based on the distortion of the image of this structure in a cross-sectional view.

show abstract

Topology of grain deformation

Cited by 37 publications

References 3 publications

Niobium in Microalloyed Rail Steels

Niobium in Microalloyed Rail Steels

Modelling of transition from upper to lower bainite in multi-component system

On the Applicability of Stereological Methods for the Modelling of a Local Plastic Deformation in Grained Structure: Mathematical Principles

Contact Info

Product

Resources

About