Cementite Dissolution in Cold Drawn Pearlitic Steel Wires: Role of Dislocations

2013 ◽  
Vol 768-769 ◽  
pp. 304-312
Author(s):  
Jay Chakraborty ◽  
Tias Maity ◽  
Mainak Ghosh ◽  
Goutam Das ◽  
Sanjay Chandra
Keyword(s):  
True Strain ◽  
Pearlitic Steel ◽  
Ferrite Matrix ◽  
Wire Drawing ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Strain Anisotropy ◽  
Cementite Dissolution ◽  
Cementite Phase

Despite numerous investigations in the past, mechanism of cementite dissolution has still remained a matter of debate. The present work investigates cementite dissolution during cold wire drawing of pearlitic steel (~ 0.8wt% carbon) at medium drawing strain (up to true strain 1.4) and the role of dislocations in the ferrite matrix on the dissolution process. Quantitative phase analysis using x-ray diffraction (XRD) confirms more than 50% dissolution of cementite phase at drawing strain ~ 1.4. Detail analysis of the broadening of ferrite diffraction lines confirms presence of strain anisotropy in ferrite due to high density of dislocations (~ 1015m-2) at drawing strain 1.4. The results of the analysis shows that the screw dislocations near the ferrite-cementite interface are predominantly responsible for pulling the carbon atoms out of the cementite phase leading to its dissolution.

Effect of interlamellar spacing on cementite dissolution during wire drawing of pearlitic steel wires

2000 ◽  
Vol 42 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Wong Jong Nam ◽  
Chul Min Bae ◽  
Sei J Oh ◽  
Soon-Ju Kwon
Keyword(s):  
Interlamellar Spacing ◽  
Pearlitic Steel ◽  
Wire Drawing ◽  
Steel Wires ◽  
Cementite Dissolution

Delamination of Pearlitic Steel Wires: Role of Strain Partition on Mechanical Properties of Pearlitic Wires

2021 ◽  
Vol 1016 ◽  
pp. 413-417
Author(s):  
Akula Durga Vara Prasad ◽  
Subrata Mukherjee
Keyword(s):  
Steel Wire ◽  
Cold Drawing ◽  
Pearlitic Steel ◽  
Wire Drawing ◽  
Strain Partitioning ◽  
Strain Mode ◽  
Steel Wires ◽  
Torsional Properties ◽  
Multiple Stages

Cold drawn wires were produced by drawing the pearlitic wire rod (5.5 mm diameter). Cold drawing involved multiple stages to a final drawing strain of ≈ 2.5. The cold drawing alters the pearlite morphology. During the wire drawing, the change in morphology is location dependent. This will create the gradient in stain and strain mode between the surface and the center. This led to have a strain partition among ferrite and cementite phases. The strain partitioning plays a major role in the final tensile and torsional performance of the cod drawn wire. The present work dealt with the experimental and their numerical simulations of stress gradients and the role of pearlite morphology on tensile and torsional properties of the pearlitic steel wire.

Evolution of Residual Micro Phase and Orientation Dependent Stresses during Cold Wire Drawing

2013 ◽  
Vol 768-769 ◽  
pp. 327-334 ◽  
Author(s):  
Martin Kriška ◽  
Jeroen Tacq ◽  
Karel van Acker ◽  
Marc Seefeldt
Keyword(s):  
True Strain ◽  
Ferrite Matrix ◽  
Wire Drawing ◽  
Microstructure Development ◽  
Synchrotron Diffraction ◽  
Physical Reason ◽  
High Deformation ◽  
Cold Wire ◽  
Deformation Regime ◽  
Significant Divergence

The residual grain and phase microstress evolutions in the ferrite matrix of pearlitic wires after several steps of cold wire drawing have been studied. Energy dispersive synchrotron diffraction revealed a significant divergence in the grain microstress evolution among differently oriented ferrite grains in the high deformation regime beyond accumulated true strain level εt ≥ 2.3.The possible physical reason for the observed divergence is discussed in terms of distinct microstructure development in this stage of the cold wire drawing.

Comparing the Role of Dislocations during Plastic Deformation of Nanocrystalline Nickel and Coarse-Grained Nickel during Cold Rolling

2008 ◽  
Vol 1090 ◽  
Author(s):  
Andreas Kulovits ◽  
Scott M Mao ◽  
Jorg M Wiezorek
Keyword(s):  
Plastic Deformation ◽  
Cold Rolling ◽  
True Strain ◽  
Grain Morphology ◽  
Coarse Grained ◽  
X Ray Diffraction ◽  
Grain Boundary Character ◽  
Transmission Electron ◽  
Average Grain Size

AbstractWe investigated plastic deformation of fully dense electrodeposited nanocrystalline (NC) Ni with an average grain size of 30-40nm. We studied the microstructural evolution during cold rolling of NC Ni to a reduction in thickness up to 76% (true strain equivalent ∼1.42). We determined changes in texture, grain morphology, grain boundary character and grain sizes as a function of cold rolling strain, using X-ray diffraction and transmission electron microscopy TEM. We compared our results of the NC Ni with our own results for cold rolled coarse grained (CG) Ni. Differences and similarities in deformation behavior are discussed with respect to well documented findings in the literature.

Measurement of Dislocation Density in Cold-Drawn Steel Wires by Means of X-Ray Bragg Profiles Analysis

2012 ◽  
Vol 184-185 ◽  
pp. 1054-1059
Author(s):  
Fan Yang ◽  
Ying Ying Fan ◽  
Yi Ming Jin
Keyword(s):  
Dislocation Density ◽  
True Strain ◽  
Pearlitic Steel ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Line Profile ◽  
Steel Wires ◽  
Initial Dislocation Density ◽  
Cold Worked

Cold-drawn pearlitic steel wires are widely used in numerous engineering fields. One of the most powerful analysis methods on determining the dislocation character of this heavily cold worked material is to investigate the X–ray diffraction line-profile broadening. Fourier line–broadening analysis in steel wires with near eutectoid composition indicates that with cumulative true strains, the initial dislocation density of 6×1014m-2in the rods increases at least one magnitude in wires. Up to 1.5×1016m-2of dislocation density is found in the ferrite lamella of wires with a true strain of 2.77.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

scholarly journals Modeling of magneto-conductivity of bismuth selenide: a topological insulator

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Field Range ◽  
X Ray ◽  
Bulk Carriers ◽  
Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

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