scholarly journals Asymmetric Twin-Roll Casting of an Al-Mg-Si-Alloy

2018 ◽  
Vol 918 ◽  
pp. 48-53 ◽  
Author(s):  
Olexandr Grydin ◽  
Mykhailo Stolbchenko ◽  
Maria Bauer ◽  
Mirko Schaper

The industrial application of high-alloyed Al-Mg-Si alloys for the production of thin strips by means of twin-roll casting is limited due to the structural inhomogeneity and segregation formation. To reach the highest mechanical properties of the finished product, a direct influence on the strip formation conditions during the twin-roll casting can be applied. Analogous to the asymmetric rolling process, additional shear stresses were created in the strip forming zone by using different circumferential velocities and torques of the caster rolls. To provide the asymmetric process conditions, only one caster roll was left driven and the second one was left idling during the casting process. The microstructure and the mechanical properties of the strips in the as-cast state as well as after the homogenization and subsequent age-hardening were analyzed. A comparison of the test results showed a positive influence of the asymmetry conditions on the strips’ properties.

2012 ◽  
Vol 452-453 ◽  
pp. 7-11 ◽  
Author(s):  
Wei Pei ◽  
Yu Hui Sha ◽  
Fang Zhang ◽  
Liang Zuo

In this paper, non-silicon steel sheets were produced by both twin-roll casting method and conventional process. Orientation characteristics and texture evolution of the sheets during casting, cold rolling and recrystallization annealing were investigated for comparison. It was found that the subsurface of twin-roll casting strips are characterized by weak {100} orientation while the central layer by random orientation. Twin-roll casting process can decrease α fiber (//RD) and increase γ fiber (//ND) during cold rolling process. Consequently, the η fiber (//RD) favorable for magnetic properties of non-silicon steels is enhanced and the detrimental {111} component is suppressed after annealing.


2011 ◽  
Vol 690 ◽  
pp. 331-334 ◽  
Author(s):  
M. Aljarrah ◽  
Elhachmi Essadiqi ◽  
D.H. Kang ◽  
In Ho Jung

The use of wrought magnesium for automobile structural components is an important component of the mass reduction strategy for automobiles to improve their fuel efficiency. Compared to Direct chill casting, Twin Roll Casting (TRC) allows major reduction of hot rolling steps in the production of Mg sheet due to the thin thickness of the as-cast strip. This TRC route can substantially reduce the time and cost to produce Mg alloy sheet product. In this work, AZ31 magnesium alloy was casted to 5 and 6 mm thick strips under different process conditions. Microstructure of these strips was analyzed using optical microscopy, SEM and EPMA. TRC strip was annealed under two different conditions: 2 hours at 330 and 1 hour at 400°C. It has been found that heat treatment at 400°C for 1 hour reduces centerline segregation significantly. TRC strips were rolled down to 2 mm and annealed at 450°C for 2 minutes. The average grain size was 4-6 µm and mechanical properties were comparable with commercial AZ31 sheet.


2016 ◽  
Vol 61 (2) ◽  
pp. 1101-1108 ◽  
Author(s):  
A. Mamala ◽  
W. Ściężor ◽  
P. Kwaśniewski ◽  
J. Grzebinoga ◽  
R. Kowal

Abstract Twin Roll Casting technology belongs to modern, integrated method of processing aluminum and its alloys. This method includes preparation of liquid metal and its continuous casting between the rotating cylindrical crystallizers, optional homogenizing treatment, cold rolling and optional interoperation or final heat treatment. Final products of TRC method are strips with a thickness from few to several millimeters, which can be directly subjected to cold rolling process to afford a sheet. Properties of final product are limited by the material’s condition, its chemical composition and also selected path of its processing technology. The paper presents research results of chemical composition and mechanical properties of strips obtained in Twin Roll Casting processing line.


2017 ◽  
Vol 735 ◽  
pp. 18-23
Author(s):  
Yuta Kashitani ◽  
Shinichi Nishida ◽  
Junshi Ichikawa ◽  
Hiroto Ohashi ◽  
Naoshi Ozawa ◽  
...  

This paper describes a vertical type twin roll strip casting process for producing aluminum alloy strip of ADC12, A3003 and A7075. Twin roll casting process is able to produce a strip from molten metal directly. Thus this process has a possibility to reduce total cost of sheet making comparing to conventional rolling process. Aluminum alloy ADC12 is a casting material that is used for die casting. A3003 is known as a wrought aluminum alloy for aluminum can body sheet. The A3003 sheet is generally produced by rolling, so it is effective for reducing a process cost to produce the strip by twin roll casting process. Aluminum alloy A7075 has high tensile strength, and it is known as a material for aerospace application. The sheet is manufactured in small quantities comparing to the other sheet aluminum alloy. It is supposed that the demand of high tensile strength aluminum sheet such as A7075 is going to increase for weight saving of structural material. In this study, twin roll casting experiment was performed to produce these three aluminum alloy strip in same experimental conditions. Castability, surface conditions and strip thickness were estimated. It was possible to cast these aluminum alloy strip.


2007 ◽  
Vol 340-341 ◽  
pp. 877-882
Author(s):  
Xiao Dong Hu ◽  
Dong Ying Ju

Twin-roll thin strip casting process combines casting and hot rolling process into a single step; in which melt and solid states exist in the casting region, so its deformation is more complex than rolling process. In this paper, Anand’s model, a unified visco-plasticity constitutive model, was employed to simulate the highly nonlinear behavior in the twin-roll casting process. Anand model’s parameters were regressed based on compression tests at various temperature and strain rate for magnesium alloy AZ31. To calculate the thermal mechanical stresses, the thermal flow of twin-roll casting process was simulated firstly; then stresses were calculate, in which the temperature field result of thermal flow was imposed as body load, and a small displacement load along roller tangential direction was imposed simultaneously in order to simulate rolling action. The deformation results can well describe the forward slip zone, backward slip zone and melt eddy zone in the casting region. Based on the results, the applicability of Anand’s model on twin-roll casting process was discussed.


2009 ◽  
Vol 614 ◽  
pp. 123-128 ◽  
Author(s):  
Hong Yang Zhao ◽  
Xiao Dong Hu ◽  
Dong Ying Ju

Experimental study on downstream rolling process for twin roll casting magnesium alloy strip was carried out. The microstructure of the casting and rolling strip were observed by OM, SEM, and TEM. The effects of homogenizing process, the parameters of rolling process and annealing after rolled on secondary rolling of AZ31B casting strip were analyzed. The results show that the twin roll casting strip are suitable for rolling at 380-420 °C after homogenizing at 400 oC for two hours, the reduction rate of each pass should be controlled lower than 18%. Mg alloy sheets with thickness from 0.3-1 mm can be produced in once annealing period in this way. By controlling the pass reduction and rolling temperature, the fabricated AZ31B Mg alloy sheets can achieve both high strength and good plasticity by grain refining below 10μm. The mechanical properties of rolled strip after annealing at 400 oC for 0.5h-1h could get tensile strength 220MPa and meantime elongation rate 20%.


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