Microstructure and Texture Development in Pure Ta Sheets Processed by Conventional Rolling and Cross Roll Rolling

2012 ◽  
Vol 706-709 ◽  
pp. 2652-2656 ◽  
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Effective Strain ◽  
High Vacuum ◽  
Diffraction Method ◽  
Vacuum State ◽  
Rolling Process ◽  
Texture Development ◽  
Experimental Result ◽  
Grain Boundary Character ◽  
Cold Rolled ◽  
Conventional Rolling

To evaluate the effect of rolling process on microstructures and textures development, this work was carried out using pure Ta sheets. For this work, conventional rolling (CR) and cross roll rolling (CRR) as a deformation process were introduced, pure Ta sheets were cold rolled to 90% in thickness reduction. After this, to obtain the recrystallized microstructure on cold rolled materials, the recrystallization heat-treatment was performed at 1200°C for 60 min under the high vacuum state. Also, to analyse the grain boundary character distributions of the annealed sheets, electron back-scattered diffraction method was introduced. As an experimental result, increase in strain rate led to the development of texture with its texture component of <111> at conventional rolling and cross roll rolling, in common. Therefore, in this study, we systematically discussed the texture development due to increase in effective strain.

Effects of Strain Rate in Cold-Rolled Pure Copper Produced by Different Rolling Processes

2011 ◽  
Vol 695 ◽  
pp. 307-311
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Effective Strain ◽  
Pure Copper ◽  
Refined Grains ◽  
Grain Boundary Character ◽  
Processed Material ◽  
Cold Rolled ◽  
Ebsd Technique ◽  
Conventional Rolling ◽  
Electron Back Scattered Diffraction

To evaluate the microstructures and mechanical properties in cross-roll rolled pure copper, comparing with conventionally rolled materials, this work was carried out. Pure copper (99.99 mass%) sheets with thickness of 5 mm were cold rolled to 90% thickness reduction by cross-roll rolling (CRR) and subsequently annealed at 400 °C for 30 min. Also, to analyze the grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was employed. As a result, the cold rolled and annealed materials consisted of significantly refined grains than that of the initial material (100 mm). Especially, the CRR processed material showed more refined grain size (6.5 mm) in average than that (9.8 mm) of conventional rolling (CR). These grain refinements directly affected an increase in mechanical properties. Therefore, the microstructural and mechanical properties development observed in both processes was systematically discussed in terms of the effective strain originated by the plastic deformation.

Microstructure and Mechanical Properties Development in Cross Roll Rolled Ni-30Cr Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 2462-2467
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Effective Strain ◽  
Initial Material ◽  
Grain Boundary Character ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolled ◽  
Conventional Rolling ◽  
The Relationship ◽  
Electron Back Scattered Diffraction

In order to evaluate the microstructure and mechanical properties of cross roll rolled Ni-30Cr alloy, comparing with conventionally rolled material, this work was carried out. The materials were cold rolled to 90% in thickness reduction by conventional rolling and cross roll rolling methods and subsequently annealed at 700°C for 30 min. After this work, in order to evaluate the grain boundary character distributions of the materials, electron back-scattered diffraction technique was introduced. The application of cross roll rolling was more effective to develop the microstructure and mechanical properties than those of conventional rolling. As a result, the grain size was significantly refined to 1.3 μm in conventional rolling and 0.6 μm in cross roll rolling, compared to initial material (30 μm), respectively. Also, these grain refinements directly affected an increase in mechanical properties. In the present study, we systematically discussed the relationship between grain size and mechanical properties in terms of an increase in effective strain.

Microstructural and Mechanical Properties Enhancement in Ultrafine Grained Ni-Cr Alloy

2012 ◽  
Vol 1372 ◽  
Author(s):  
Kuk Hyun Song ◽  
Hye Jin Lee ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Effective Strain ◽  
Initial Material ◽  
Grain Boundary Character ◽  
Ultrafine Grained ◽  
Processed Material ◽  
Average Grain Size ◽  
Ebsd Technique ◽  
Conventional Rolling

ABSTRACTThe present study was carried out to evaluate the microstructures and mechanical properties of severely deformed Ni-30Cr alloy. Cross-roll rolling (CRR) as severe plastic deformation (SPD) process was introduced and Ni-30Cr alloy sheets were cold rolled to a 90% thickness reduction and subsequently annealed at 700 °C for 30 min so as to obtain the recrystallized microstructure. For the analysis of grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was introduced. CRR on Ni-30Cr alloy was effective to enhance the grain refinement through heat treatment; consequently, average grain size was significantly reduced from 33 μm in initial material to 0.6 μm in CRR processed material. This grain refinement directly affected the mechanical properties improvement, in which yield and tensile strengths were significantly increased than those of initial material. In this study, we systematically discussed the grain refinement, accompanying with increase in mechanical properties, in terms of the effective strain imposed by CRR, comparing with conventional rolling (CR).

Texture Development in Cold Rolled and Annealed Ta

2011 ◽  
Vol 695 ◽  
pp. 153-157 ◽  
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Grain Size ◽  
Elevated Temperature ◽  
Annealing Temperature ◽  
High Vacuum ◽  
Surface Oxidation ◽  
Reduction Ratio ◽  
Texture Development ◽  
Fibre Texture ◽  
Annealed Material ◽  
Cold Rolled

In order to investigate the texture development in cold rolled and annealed tantalum (Ta), the present study was carried out. For this work, cold rolling was performed up to ~ 96% reduction in thickness, and annealing was performed at elevated temperature up to ~ 1200 °C for 60 min under the high vacuum to prevent the surface oxidation. As a result, increase in the reduction ratio of the cold rolled Ta was effective to develop the a fibre texture, with its texture components such as (001)<110> and (112)<110>. Also, resulting grain size was more refined by increase in reduction ratio, consequently, 96% cold rolled and annealed material showed the best refined grain size. However, in case of annealed material, g fibre texture with its texture component, such as (111)<121> and (111)<112>, was developed by increase in annealing temperature. In this study, we systematically discussed the texture development due to the increase in reduction ratio.

Grain Refinement and Mechanical Properties Enhancement in Cross Roll Rolled Pure Copper

2012 ◽  
Vol 1372 ◽  
Author(s):  
Kuk Hyun Song ◽  
Han Sol Kim ◽  
Won Yong Kim
Keyword(s):  
Mechanical Properties ◽  
Pure Copper ◽  
Normal Direction ◽  
Refined Grains ◽  
Grain Boundary Character ◽  
Processed Material ◽  
Cold Rolled ◽  
Ebsd Technique ◽  
Conventional Rolling ◽  
Electron Back Scattered Diffraction

ABSTRACTTo evaluate the microstructures and mechanical properties in cross-roll rolled pure copper, comparing with conventionally rolled materials, this work was carried out. Pure copper (99.99 mass%) sheets with thickness of 5 mm were cold rolled to 90% thickness reduction by cross-roll rolling (CRR) and subsequently annealed at 400 °C for 30 min. Also, to analyze the grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was employed. As a result, the cold rolled and annealed materials consisted of significantly refined grains than that of the initial material (100 μm). Especially, the CRR processed material showed more refined grain size (6.5 μm) in average than that (9.8 μm) of conventional rolling (CR). These grain refinements directly affected an increase in mechanical properties. Furthermore, the texture development in CRR processed material, in which <112> grains were densely distributed in the normal direction (ND), was more effective to enhance the yield strength.

scholarly journals 3D-FEM Simulation of Hot Rolling Process and Characterization of the Resultant Microstructure of a Light-Weight Mn Steel

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 569
Author(s):  
Ana Claudia González-Castillo ◽  
José de Jesús Cruz-Rivera ◽  
Mitsuo Osvaldo Ramos-Azpeitia ◽  
Pedro Garnica-González ◽  
Carlos Gamaliel Garay-Reyes ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Thermomechanical Processing ◽  
Computational Simulation ◽  
Effective Strain ◽  
Fem Simulation ◽  
Rolling Process ◽  
3D Fem ◽  
Hot Rolling Process ◽  
Mn Steel

Computational simulation has become more important in the design of thermomechanical processing since it allows the optimization of associated parameters such as temperature, stresses, strains and phase transformations. This work presents the results of the three-dimensional Finite Element Method (FEM) simulation of the hot rolling process of a medium Mn steel using DEFORM-3D software. Temperature and effective strain distribution in the surface and center of the sheet were analyzed for different rolling passes; also the change in damage factor was evaluated. According to the hot rolling simulation results, experimental hot rolling parameters were established in order to obtain the desired microstructure avoiding the presence of ferrite precipitation during the process. The microstructural characterization of the hot rolled steel was carried out using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the phases present in the steel after hot rolling are austenite and α′-martensite. Additionally, to understand the mechanical behavior, tensile tests were performed and concluded that this new steel can be catalogued in the third automotive generation.

Estimation of Residual Stress in Cold Rolled Iron-Disks Using Magnetic and Ultrasonic Methods and Neutron Diffraction Technique

1994 ◽  
Vol 376 ◽  
Author(s):  
V.L. Aksenov ◽  
A.M. Balagurov ◽  
G.D Bokuchava ◽  
J. Schreiber ◽  
Yu.V. Taran Frank
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Sheet Metal ◽  
Diffraction Method ◽  
Calibration Procedure ◽  
Rolled Sheet ◽  
Forming Process ◽  
Practical Applications ◽  
Ultrasonic Methods ◽  
Cold Rolled

ABSTRACTVariation of internal stress states in cold rolled sheet metal can essentially influence the result of forming processes. Therefore it is important to control the forming process by a practicable in line testing method. For this purpose magnetic and ultrasonic nondestructive methods are available. However, it is necessary to calibrate these techniques. This paper describes a first step of such a calibration procedure making use of the neutron diffraction method. On the basis of the diffraction results an assessment of the magnetic and ultrasonic methods for the estimation of residual stress in the cold rolled iron-disks was made. Reasonable measuring concepts for practical applications to forming processes with cold rolled sheet metal are discussed.

Influence of the Deformation Method on the Microstructure Changes in AZ31 Magnesium Alloy Round Rods Obtained by the Rolling Process

2016 ◽  
Vol 716 ◽  
pp. 864-870
Author(s):  
Andrzej Stefanik ◽  
Piotr Szota ◽  
Sebastian Mróz ◽  
Teresa Bajor ◽  
Sonia Boczkal
Keyword(s):  
Magnesium Alloy ◽  
Numerical Modelling ◽  
Rolling Mill ◽  
Laboratory Tests ◽  
Effective Strain ◽  
Rolling Process ◽  
Az31 Magnesium Alloy ◽  
Deformation Method ◽  
Microstructure Changes ◽  
Skew Rolling

This paper presents the research results of the microstructure changes of the round rods of AZ31 magnesium alloy in the hot rolling processes. The rolling was conducted in duo mill and a three-high skew rolling mill. Numerical modelling of the AZ31 magnesium alloy round rods rolling process was conducted using a computer program Forge 2011®. The verification of the results of numerical modelling was carried out during laboratory tests in a two-high rolling mill D150 and a three-high skew rolling mill RSP 40/14. Distributions of the total effective strain and temperature during AZ31 rods rolling process were determined on the basis of the theoretical analysis. Microstructure and texture changes during both analysed processes were studied.

Evaluation of Blister Behavior for U10Mo Mini Fuel Plates With Cold Rolled Foils

2012 ◽  
Author(s):  
Hakan Ozaltun ◽  
Samuel J. Miller
Keyword(s):  
Cold Rolling ◽  
Thermal Cycling ◽  
Cold Work ◽  
Rolling Process ◽  
Foil Thickness ◽  
Rolled Plate ◽  
Stress Profile ◽  
Wide Range ◽  
Threshold Temperatures ◽  
Cold Rolled

This article aims to provide possible mechanical causes for the lowered blister temperatures of RERTR-12 and AFIP-4 fuel plates. Recent experimental investigations to determine the blister threshold temperatures have indicated lower thresholds for similar plates with comparable burn-up histories. Measured blister temperatures of roughly 100 °C lower compared to the previously tested plates may not be satisfactory for some plates. The primary differences between recent experiments and previous tests are: (1) An aggressive cold work process involving large thickness reduction ratios without normalization or full annealing (2) Subjecting the plates to a thermal cycling process prior to irradiation, and finally (3) A primarily frontal neutron flux as opposed to a transverse flux profile. It is believed that the stress field has implications to blister behavior. To investigate this claim, the stress-strain states for the fabrication procedure were evaluated. First, the residual stress profile caused by the cold rolling process was calculated. Modeling of the cold rolling process has shown confirmation of residual stresses of considerable magnitude and the existence of stress gradients with respect to foil thickness prior to the HIP process. Once calculated, these stress profiles were used as an initial condition for the fabrication process. Due to the variation in stress fields depending on location at which a foil is cut from the cold rolled plate, three representative regions were selected and implemented in the HIP simulation. Variation in stresses, depending on location of the cold rolled plate as well and variation in the through-thickness, results in a wide range of mechanical stress states. This suggests that inhomogeneous irradiation and thermal cycling behavior will result from the use of cold rolled foils. Additionally, these results suggest that there will be fundamental differences in fuel plate behavior observed between plates fabricated with cold rolled foils versus hot rolled and fully annealed foils.

Optimization of Rolling Modes on the Mill 1700 of JSC "ArselorMittal Temirtau" with Aim to Increase Quality of Sheet Rolled Products

2015 ◽  
Vol 1095 ◽  
pp. 786-794
Author(s):  
A.B. Naizabekov ◽  
V.A. Talmazan ◽  
S.N. Lezhnev ◽  
E.A Panin ◽  
А.S. Erzhanov ◽  
...  
Keyword(s):  
Surface Defects ◽  
Mechanical Damage ◽  
Rolling Process ◽  
Rolled Sheet ◽  
Strip Rolling ◽  
Technological Factors ◽  
Second Stage ◽  
Sheet Surface ◽  
Cold Rolled

Used the influence of technological factors of the rolling process on the intensity of the rolling out of the defect to determine the value of deformation and the coefficient of use of the plasticity resource. Introduced the notion of residual coefficient of plasticity resource in the second stage of transformation of the defect. Found that the causes of deterioration of the quality of cold-rolled sheet can be numerous defects of mechanical origin, caused by mechanical damage of the sheet surface. Conducted an analysis of profiles rolling modes, rolled on the mill 1700. With the use of existing methods calculated DUPR on workshop modes of rolling of specified profiles with and without considering the surface defects. Carried an optimization of the modes of strip rolling with surface defects.

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