scholarly journals Through-Thickness Microstructure and Strain Distribution in Steel Sheets Rolled in a Large-Diameter Rolling Process

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 91
Author(s):  
Tadanobu Inoue ◽  
Hai Qiu ◽  
Rintaro Ueji
Keyword(s):  
Strain Distribution ◽  
Steel Sheet ◽  
Large Diameter ◽  
Rolling Process ◽  
Equivalent Strain ◽  
Rolled Sheet ◽  
Low Carbon ◽  
Element Analysis ◽  
Ultrafine Grained ◽  
Niobium Microalloyed Steel

The rolling condition for fabricating a low-carbon niobium-microalloyed steel sheet with an ultrafine-grained (UFG) structure was examined through rolling experiments and finite element analysis. A large-diameter rolling process was proposed to create a UFG structure. The rolling was conducted near the transformation point, Ar3, from austenite to ferrite. The Ar3 was measured at the surface and the center of the sheet. First, the through-thickness microstructure and equivalent strain distribution in a 1-pass rolled sheet 2.0 mm thick were examined. In the rolling experiments, the embedded pin method was employed to understand through-thickness deformation. The magnitude of the equivalent strain to obtain a UFG structure was estimated to be 2.0. Based on these results, the fabrication of a 2 mm UFG steel sheet by 3-pass rolling for an initial thickness of 14.5 mm was attempted by the proposed large-diameter rolling process.

scholarly journals Optimum Pass Design of Bar Rolling for Producing Bulk Ultrafine-Grained Steel by Numerical Simulation

2010 ◽  
Vol 654-656 ◽  
pp. 1561-1564 ◽  
Author(s):  
Tadanobu Inoue
Keyword(s):  
Strain Distribution ◽  
Large Strain ◽  
Rolling Process ◽  
Low Carbon ◽  
Shape Variation ◽  
Element Analysis ◽  
Cross Sectional ◽  
Ultrafine Grained ◽  
Sectional Shape ◽  
Ultrafine Grained Steel

The groove design for creating ultrafine-grained low-carbon steel through a caliber rolling process was studied from the viewpoint of the large strain accumulation and cross-sectional shape variation in a bar. A three-dimensional finite element analysis was employed for this purpose. The caliber rolling process of foval (flat-like-oval)/square type was proposed as a method to efficiently introduce a large strain in material. The relationship among the foval configuration, strain, and cross-sectional shape was examined in the caliber rolling. The influence of the equivalent strain distribution by 1st pass (foval rolling) depends strongly on the strain distribution and a cross-sectional shape by 2nd pass, and the foval configuration to accumulate a large strain efficiently was shown. The optimum pass schedule to fabricate a 13mm square bar of ultrafine-grained steel from a 24 mm square bar by caliber rolling at warm working temperatures was proposed.

Effect of Deformation Mode on Texture of Ultrafine-Grained Low Carbon Steel Processed by Warm Caliber Rolling

2010 ◽  
Vol 638-642 ◽  
pp. 2793-2798 ◽  
Author(s):  
Tadanobu Inoue ◽  
Fu Xing Yin ◽  
Yuuji Kimura
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Diffraction Method ◽  
Deformation Mode ◽  
Equivalent Strain ◽  
Low Carbon ◽  
Element Analysis ◽  
Ultrafine Grained ◽  
Strain Components ◽  
Pass Through

The evolution of crystallographic texture with equivalent strain, eq, was studied in low carbon steel bars fabricated using multi-pass warm caliber rolling. Finite element analysis was carried out to evaluate eq accumulated and strain components introduced with each pass through the rolled bars. The texture at characteristic deformation sites on the cross section in the bars was analyzed using the electron back-scattered diffraction method. Although the texture in the area around the center was dominated by a strong RD//<101>, in the other two areas, a RD//<101> texture was not produced. It is clarified that this difference results from three deformation modes during rolling. Consequently, the areas around the corners, where eq of over 5.7 is introduced, are filled with ultrafine ferrite grains of below 680 nm, and the texture in the areas is random regardless of the increase of eq.

Measurement and Calculation of Elastic Properties in Low Carbon Steel Sheet

2005 ◽  
Vol 495-497 ◽  
pp. 1591-1596 ◽  
Author(s):  
Vladimir Luzin ◽  
S. Banovic ◽  
Thomas Gnäupel-Herold ◽  
Henry Prask ◽  
R.E. Ricker
Keyword(s):  
Carbon Steel ◽  
Elastic Property ◽  
Elastic Properties ◽  
Steel Sheet ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Forming Process ◽  
Element Analysis ◽  
Wide Range ◽  
Carbon Steel Sheet

Low carbon steel (usually in sheet form) has found a wide range of applications in industry due to its high formability. The inner and outer panels of a car body are good examples of such an implementation. While low carbon steel has been used in this application for many decades, a reliable predictive capability of the forming process and “springback” has still not been achieved. NIST has been involved in addressing this and other formability problems for several years. In this paper, texture produced by the in-plane straining and its relationship to springback is reported. Low carbon steel sheet was examined in the as-received condition and after balanced biaxial straining to 25%. This was performed using the Marciniak in-plane stretching test. Both experimental measurements and numerical calculations have been utilized to evaluate anisotropy and evolution of the elastic properties during forming. We employ several techniques for elastic property measurements (dynamic mechanical analysis, static four point bending, mechanical resonance frequency measurements), and several calculation schemes (orientation distribution function averaging, finite element analysis) which are based on texture measurements (neutron diffraction, electron back scattering diffraction). The following objectives are pursued: a) To test a range of different experimental techniques for elastic property measurements in sheet metals; b) To validate numerical calculation methods of the elastic properties by experiments; c) To evaluate elastic property changes (and texture development) during biaxial straining. On the basis of the investigation, recommendations are made for the evaluation of elastic properties in textured sheet metal.

scholarly journals Recrystallization Microstructure Prediction of a Hot-Rolled AZ31 Magnesium Alloy Sheet by Using the Cellular Automata Method

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Ming Chen ◽  
Xiaodong Hu ◽  
Hongyang Zhao ◽  
Dongying Ju
Keyword(s):  
Flow Stress ◽  
Magnesium Alloy ◽  
Cellular Automata ◽  
Process Analysis ◽  
Rolling Process ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Rolled Sheet ◽  
Element Analysis ◽  
Hot Rolled

A large reduction rolling process was used to obtain complete dynamic recrystallization (DRX) microstructures with fine recrystallization grains. Based on the hyperbolic sinusoidal equation that included an Arrhenius term, a constitutive model of flow stress was established for the unidirectional solidification sheet of AZ31 magnesium alloy. Furthermore, discretized by the cellular automata (CA) method, a real-time nucleation equation coupled flow stress was developed for the numerical simulation of the microstructural evolution during DRX. The stress and strain results of finite element analysis were inducted to CA simulation to bridge the macroscopic rolling process analysis with the microscopic DRX activities. Considering that the nucleation of recrystallization may occur at the grain and R-grain boundary, the DRX processes under different deformation conditions were simulated. The evolution of microstructure, percentages of DRX, and sizes of recrystallization grains were discussed in detail. Results of DRX simulation were compared with those from electron backscatter diffraction analysis, and the simulated microstructure was in good agreement with the actual pattern obtained using experiment analysis. The simulation technique provides a flexible way for predicting the morphological variations of DRX microstructure accompanied with plastic deformation on a hot-rolled sheet.

Microstructure Evolution during Warm Deformation of Low Carbon Steel with Dispersed Cementite

2007 ◽  
Vol 558-559 ◽  
pp. 505-510 ◽  
Author(s):  
J. Gallego ◽  
Alberto Moreira Jorge ◽  
O. Balancin
Keyword(s):  
Microstructure Evolution ◽  
Large Strain ◽  
Cell Structure ◽  
Lath Martensite ◽  
Low Carbon Steel ◽  
Testing Temperature ◽  
Equivalent Strain ◽  
Low Carbon ◽  
Ultrafine Grained ◽  
Ebsd Technique

The microstructure evolution and mechanical behavior during large strain of a 0.16%CMn steel has been investigated by warm torsion tests. These experiments were carried out at 685 °C at equivalent strain rate of 0.1 s-1. The initial microstructure composed of a martensite matrix with uniformly dispersed fine cementite particles was attained by quenching and tempering. The microstructure evolution during tempering and straining was performed through interrupted tests. As the material was reheated to testing temperature, well-defined cell structure was created and subgrains within lath martensite were observed by TEM; strong recovery took place, decreasing the dislocation density. After 1 hour at the test temperature and without straining, EBSD technique showed the formation of new grains. The flow stress curves measured had a peculiar shape: rapid work hardening to a hump, followed by an extensive flow-softening region. 65% of the boundaries observed in the sample strained to ε = 1.0 were high angle grain boundaries. After straining to ε = 5.0, average ferrite grain size close to 1.5 1m was found, suggesting that dynamic recrystallization took place. Also, two sets of cementite particles were observed: large particles aligned with straining direction and smaller particles more uniformly dispersed. The fragmentation or grain subdivision that occurred during reheating and tempering time was essential for the formation of ultrafine grained microstructure.

scholarly journals Determination of Non-Recrystallization Temperature for Niobium Microalloyed Steel

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2639
Author(s):  
Mohammad Nishat Akhtar ◽  
Muneer Khan ◽  
Sher Afghan Khan ◽  
Asif Afzal ◽  
Ram Subbiah ◽  
...  
Keyword(s):  
Microalloyed Steel ◽  
Casting Process ◽  
Rolling Process ◽  
Recrystallization Temperature ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Nb Microalloyed Steel ◽  
Niobium Microalloyed Steel ◽  
Multiple Hit ◽  
Deformation Tests

In the present investigation, the non-recrystallization temperature (TNR) of niobium-microalloyed steel is determined to plan rolling schedules for obtaining the desired properties of steel. The value of TNR is based on both alloying elements and deformation parameters. In the literature, TNR equations have been developed and utilized. However, each equation has certain limitations which constrain its applicability. This study was completed using laboratory-grade low-carbon Nb-microalloyed steels designed to meet the API X-70 specification. Nb- microalloyed steel is processed by the melting and casting process, and the composition is found by optical emission spectroscopy (OES). Multiple-hit deformation tests were carried out on a Gleeble® 3500 system in the standard pocket-jaw configuration to determine TNR. Cuboidal specimens (10 (L) × 20 (W) × 20 (T) mm3) were taken for compression test (multiple-hit deformation tests) in gleeble. Microstructure evolutions were carried out by using OM (optical microscopy) and SEM (scanning electron microscopy). The value of TNR determined for 0.1 wt.% niobium bearing microalloyed steel is ~ 951 °C. Nb- microalloyed steel rolled at TNR produce partially recrystallized grain with ferrite nucleation. Hence, to verify the TNR value, a rolling process is applied with the finishing rolling temperature near TNR (~951 °C). The microstructure is also revealed in the pancake shape, which confirms TNR.

scholarly journals Improvement of the coiling stress calculation model for a mandrel-sleeve-coil

2022 ◽  
Vol 14 (1) ◽  
pp. 168781402110704
Author(s):  
Yonghui Park ◽  
Kyutae Park ◽  
Changwoo Lee ◽  
Wei Shi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steel Sheet ◽  
Circumferential Stress ◽  
Rolling Process ◽  
Constant Thickness ◽  
Analysis Model ◽  
Element Analysis ◽  
Steel Rolling ◽  
Stress Calculation

The steel rolling process employs a coiling-uncoiling process in which a steel sheet is wound and unwound in a coil shape using a coiler to efficiently produce a long steel sheet with a constant thickness. As front and rear tension is required when the steel sheet enters and exits the rolling mill, the coiler introduces tension in the steel sheet through the control of the rotational speed. As the coil is produced, coiling tension accumulates, and pressure is applied to the inside of the coil. Finite element analysis and stress calculation analysis were derived from previous studies to prevent such pressure increases in the sleeves and coils. However, the radial and circumferential stresses at arbitrary positions inside the coil cannot be accurately determined by considering without the stresses’ difference in the thickness direction based on the assumption that the coil’s thickness is thin. In this study, an analytical model that can accurately calculate the sleeve and coil stress during elastic deformation was established by improving the internal circumferential stress generated when the steel sheet is bent into a coil and the radial stress equation associated with the beam bending theory. In addition, by comparing the finite element analysis model results reflecting the same coiling condition, this model’s validity was verified by confirming the consistency of the results.

Finite Element Analysis of Rolling Process for Pilger Mill

2014 ◽  
Vol 881-883 ◽  
pp. 1420-1423 ◽  
Author(s):  
Ning An ◽  
Liu Hai
Keyword(s):  
Rolling Force ◽  
Equivalent Stress ◽  
Rolling Process ◽  
Equivalent Strain ◽  
Roll Pass ◽  
Element Analysis ◽  
Pipe Rolling ◽  
Cold Rolled ◽  
Simulation Results ◽  
Deform 3D

For the simulation of cold rolled 20Cr steel pipe rolling process the DEFORM-3D being used, the simulation results include the equivalent stress, equivalent strain and rolling force distribution in deformation zone. The stress state of the pipe reducer section is analyzed, analysis shows that the simulation result is approximate the theoretical calculation. The simulation result shows the roll pass and openning effect on the rolling pipe. A view put forward is to compare the simulation results with the actual production and find out their differences. A proposal is made to establish a corresponding database based on simulation and production data.

High-Temperature Severe Plastic Deformation of Ferritic Steel by Torsion

2010 ◽  
Vol 667-669 ◽  
pp. 403-408
Author(s):  
Aries Setiawan ◽  
Daisuke Terada ◽  
Nobuhiro Tsuji
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Strain Rate ◽  
Equivalent Strain ◽  
Phase Region ◽  
Low Carbon ◽  
Ultrafine Grained ◽  
Lower Strain ◽  
Higher Temperature ◽  
Torsion Deformation

An ultra-low carbon IF steel was heavily deformed up to an equivalent strain of 36 at various high temperatures of ferrite single-phase region and various strain rates. Effects of temperature and strain rate on the microstructures evolved in torsion deformation were clarified. On the other hand, it was found that homogeneous ultrafine grained structures were not obtained by the present torsion deformation though very high strain was applied. The coarser grain sizes than those obtained by conventional severe plastic deformation (like ARB) were due to the deformation at higher temperature and lower strain rate, but lower fraction of high-angle grain boundaries in the torsion specimen was suggested to be attributed to the characteristics of monotonic torsion (or simple shear) deformation including the way of strain evaluation.

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