An experimental study of the mean effective strain in rod (or bar) rolling process

2000 ◽  
Vol 6 (6) ◽  
pp. 525-531 ◽  
Author(s):  
Youngseog Lee ◽  
Sangwoo Choi ◽  
Heesan Kim ◽  
Woong Yong Choo
Keyword(s):  
Experimental Study ◽  
Effective Strain ◽  
Rolling Process ◽  
Bar Rolling ◽  
The Mean

scholarly journals Experimental study on the mean flow characteristics of a supersonic multiple jet configuration

2021 ◽  
Vol 108 ◽  
pp. 106377
Author(s):  
Mohammed Faheem ◽  
Aqib Khan ◽  
Rakesh Kumar ◽  
Sher Afghan Khan ◽  
Waqar Asrar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Flow Characteristics ◽  
Mean Flow ◽  
The Mean

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.

scholarly journals The Influence of the Asymmetric Arb Process on the Properties of Al-Mg-Al Multi-Layer Sheets / Wpływ Asymetrii W Procesie Arb Na Właściwości Wielowarstwowych Blach Al-Mg-Al

2015 ◽  
Vol 60 (4) ◽  
pp. 2821-2826 ◽  
Author(s):  
A. Wierzba ◽  
S. Mróz ◽  
P. Szota ◽  
A. Stefanik ◽  
R. Mola
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Tensile Strength ◽  
Rolling Process ◽  
Asymmetry Factor ◽  
Relative Reduction ◽  
Test Results ◽  
Initial Thickness ◽  
Asymmetric Rolling ◽  
Aluminium Layer

The paper presents the results of the experimental study of the three-layer Al-Mg-Al sheets rolling process by the ARB method. The tests carried out were limited to single-pass symmetric and asymmetric rolling processes. An Al-Mg-Al package with an initial thickness of 4 mm (1-2-1 mm) was subjected to the process of rolling with a relative reduction of 50%. To activate the shear band in the strip being deformed, an asymmetry factor of av=2 was applied. From the test results, an increase in the tensile strength of the multi-layer Al-Mg-Al sheets obtained from the asymmetric process was observed. Microhardness tests did not show any significant differences in aluminium layer between respective layers of sheets obtained from the symmetric and the asymmetric process. By contrast, for the magnesium layer, an increase in microhardness from 72 HV to 79 HV could be observed for the asymmetric rolling. The analysis of the produced Al-Mg-Al sheets shows that the good bond between individual layers and grain refinement in the magnesium layer contributed to the obtaining of higher mechanical properties in the multi-layer sheets produced in the asymmetric process compared to the sheets obtained from the symmetric process.

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.

Quasi-Experimental study of effects of lighting on rest, activity and melatonin in postpartum women

2021 ◽  
Vol 74 (6) ◽  
Author(s):  
Cristina Furtado Volcov ◽  
Eliana Moreira Pinheiro ◽  
Miriam Harumi Tsunemi ◽  
Fernanda Gaspar do Amaral ◽  
Ariane Ferreira Machado Avelar ◽  
...  
Keyword(s):  
Experimental Study ◽  
Comparison Group ◽  
Total Load ◽  
Long Wavelength ◽  
Light Regimen ◽  
Early Postpartum ◽  
Comparison Groups ◽  
Quasi Experimental ◽  
The Mean ◽  
Experimental Group

ABSTRACT Objectives: to compare the parameters of the activity/rest cycle of early postpartum breastfeeding women under a controlled and uncontrolled long wavelength ray light regimen. Methods: quasi-experimental study with breastfeeding women and their babies during postnatal rooming-in, São Paulo, Brazil. Participants were allocated to either an experimental (intervention) or a comparison group. The intervention involved exposure of the woman in a controlled room with artificial long wavelength ray light at night. Each woman’s level of 6-sulfatoxymelatonin at 24 hours and activity/rest times was analyzed. Results: the mean activity/rest times of women in the experimental and comparison groups were similar. The mean percentages of total load of 6-sulfatoxymelatonin during the day and night were similar (p=0.09). At 24 hours, the experimental group presented a significantly lower mean percentage of total load compared to the comparison group (p=0.04). Conclusions: women who stayed in the room with long-wavelength artificial light showed no difference in activity/rest and 6-sulfatoxymelatonin levels in the early postpartum period.

The Influence of the Interstand Tension of the Band on Roll Wear during the Continuous Groove-Rolling Process

2015 ◽  
Vol 220-221 ◽  
pp. 898-904 ◽  
Author(s):  
Piotr Szota ◽  
Sebastian Mróz ◽  
Andrzej Stefanik ◽  
Henryk Dyja
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Quantitative Evaluation ◽  
Theoretical Study ◽  
Rolling Process ◽  
Wear Model ◽  
Bar Rolling ◽  
Groove Rolling ◽  
Roll Wear ◽  
Round Bar

Numerical modelling of the round bar rolling process, while considering the wear of passes depending on their shape, was carried out within the present work. The analysis of the rolling process was conducted thus analysing the influence of interstand tension on roll wear. For the theoretical study of the rolling process, Forge2011® was employed, which is finite element method-relying software that enables the thermo-mechanical simulation of rolling processes in a triaxial state of strain. The wear model implemented in Forge2011® permits no quantitative evaluation, but only a comparative analysis of the wear of rolls. In order to use the results of simulation employing the simplified Archard model for the quantitative evaluation of roll wear, it is necessary to define the factor of wear and the hardness of the tool as a function of temperature.

scholarly journals Kadar Prostaglandin dan Endorfin pada Remaja dengan Dismenore Primer yang diberi Hidroterapi Hangat dan Dingin

2020 ◽  
Vol 12 (1) ◽  
pp. 115-121
Author(s):  
Andi Asrina ◽  
Arsyad Aryadi ◽  
Nilawati Andi
Keyword(s):  
Experimental Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
Primary Dysmenorrhea ◽  
Not Given ◽  
Elisa Kit ◽  
Group Design ◽  
Prostaglandin Level ◽  
Post Test ◽  
Quasi Experimental ◽  
The Mean

This study aims to determine the comparison of prostaglandin and endorphin levels in adolescents with primary dysmenorrhea with and without warm (37-40oC) and cold (18-20oC) hydrotherapy. This quasi-experimental study with a post-test only controls group design was carried out in Islamic Boarding Schools with a sample of 36 young girls divided into 3 groups: 12 teens given warm hydrotherapy, 12 teens given cold hydrotherapy and 12 teens not given intervention (control). Blood plasma is taken after an intervention is given on the first day of menstruation. Examination of prostaglandin and endorphins levels using the enzyme-linked immunosorbent assay (ELISA) kit method. After cold hydrotherapy, the mean levels of prostaglandins in the cold hydrotherapy group were twice higher (569 pg/ml) compared to controls (394 pg/ml). The mean prostaglandin level in the warm hydrotherapy group also showed an increase prostaglandin (437 pg/ml) compared to the control (394 pg/ml). In addition to increasing levels of prostaglandins, increased levels of endorphins also occurred in the group given warm hydrotherapy (154 pg/ml) and the group was given cold hydrotherapy (187 pg/ml) compared to the control (119 pg/ml) p = 0.001. The conclusion in this study is that warm and cold hydrotherapy can increase levels of prostaglandins and endorphins in adolescents with primary dysmenorrhea. However, cold hydrotherapy increases endorphin levels higher than warm hydrotherapy. Key words: Prostaglandin, Endorphin, Hydrotherapy, Primary Dismenorrhea.

scholarly journals Collisional Relaxation of Fast Electrons Energy in Gas

2021 ◽  
Vol 248 ◽  
pp. 04002
Author(s):  
Alexander Metel ◽  
Enver Mustafaev ◽  
Yury Melnik ◽  
Khaled Hamdy
Keyword(s):  
Experimental Study ◽  
Glow Discharge ◽  
Electron Energy ◽  
Initial Energy ◽  
Gas Pressure ◽  
Collisional Relaxation ◽  
Fast Electrons ◽  
Electrostatic Confinement ◽  
The Mean

We present results of theoretical and experimental study of collisional relaxation of fast electrons energy in gas. The dependence on the gas pressure p and electron energy ε of the mean pass Λ of fast electrons injected into a gas being sufficient to spend on ionization all their initial energy ε has been calculated. It was found that Λ is directly proportional to ε2 and inversely proportional to the gas pressure. To sustain glow discharge with electrostatic confinement of fast electrons, Λ should be less than the mean way to the anode of emitted by the cathode electrons.

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