Thermal Flow Simulation on Twin Roll Casting Process for Thin Strip Production of Magnesium Alloy

2005 ◽  
pp. 439-444
Author(s):  
Dong Ying Ju ◽  
Hong-Yang Zhao ◽  
Xiao Dong Hu ◽  
Koichi Ohori ◽  
Mituo Tougo
Keyword(s):  
Magnesium Alloy ◽  
Flow Simulation ◽  
Casting Process ◽  
Thin Strip ◽  
Thermal Flow ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll ◽  
Strip Production

Thermal Flow Simulation on Twin Roll Casting Process for Thin Strip Production of Magnesium Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 439-444 ◽  
Author(s):  
Dong Ying Ju ◽  
Hong Yang Zhao ◽  
Xiao Dong Hu ◽  
Koichi Ohori ◽  
Mituo Tougo
Keyword(s):  
Flow Simulation ◽  
Casting Process ◽  
Thin Strip ◽  
Process Conditions ◽  
Thermal Flow ◽  
Roll Casting ◽  
Simulation Based ◽  
Twin Roll ◽  
Mg Melt ◽  
Strip Production

Strip continuous casting by twin roll method is a rapidly solidifying process, which can directly produce thin strips,reduce energy consumption and product cost of various metal materials. However, the casting of magnesium alloys with large solidifying ranges lead to some problems such as surface and internal defect, variation of solidification finish point for Mg sheet. In this research, the process conditions for a twin roll caster are analyzed by thermal flow simulation. The effect of type and dimension of delivery nozzles on production of Mg alloy are studied. A proper match of the setback distance of thin nozzle and casting speed is studied by thermal flow simulation, based on the characteristics of Mg melt handling, flow dynamics control and solidification.

Thermal flow simulation of twin-roll casting magnesium alloy

2012 ◽  
Vol 17 (4) ◽  
pp. 479-483 ◽  
Author(s):  
Xiao-dong Hu ◽  
Dong-ying Ju ◽  
Hong-yang Zhao
Keyword(s):  
Magnesium Alloy ◽  
Flow Simulation ◽  
Thermal Flow ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

Thermal Flow-Solidification Simulation and Analysis of Strip Defects in Vertical Twin-Roll Casting of Magnesium Alloy

2015 ◽  
Vol 833 ◽  
pp. 15-18 ◽  
Author(s):  
Zhi Pu Pei ◽  
Dong Ying Ju ◽  
Hong Yang Zhao ◽  
Xiao Dong Hu
Keyword(s):  
Temperature Distribution ◽  
Magnesium Alloy ◽  
Casting Process ◽  
Thermal Flow ◽  
Twin Roll Casting ◽  
Solidification Simulation ◽  
Roll Casting ◽  
Pool Level ◽  
Cast Magnesium ◽  
Twin Roll

A quantitative understanding of the twin-roll casting process is required to get high quality as-cast magnesium alloy strips. In this paper, a thermal flow-solidification simulation was carried out to study the behavior of casting zone and its effects on defects generation deeply. Results show that a lower pouring temperature is not suitable for producing defect-free magnesium alloy strips. With increasing of the casting speed, the tendency of cracks formation will getting smaller because of the more uniform temperature distribution. A low pool level leads to a small metal-roll contact area, and a sharp temperature distribution will generates under this situation, which is not good for strips quality.

Thermal Flow Simulation and Concave Type Slot Nozzle Design for Twin Roll Casting of Magnesium Alloy AZ31

2007 ◽  
Vol 539-543 ◽  
pp. 5037-5043 ◽  
Author(s):  
Xiao Dong Hu ◽  
Dong Ying Ju ◽  
Hong Yang Zhao
Keyword(s):  
Magnesium Alloy ◽  
Flow Behavior ◽  
Flow Simulation ◽  
Thermal Flow ◽  
Slot Nozzle ◽  
Alloy Az31 ◽  
Twin Roll Casting ◽  
Magnesium Alloy Az31 ◽  
Roll Casting ◽  
Twin Roll

Twin- roll casting of magnesium alloys is a rapidly solidifying process, which can directly produce thin strips from molten metal. In this paper, based on a pilot vertical type twin-roll caster, 3D models of twin-roll casting process were used for simulation of thermal flow and solidification on depending of casting speed, molten pool level and pouring temperature. The effect of side dams on thermal flow behavior was also considered. Based on the analyzed results, a proper concave slot nozzle was designed to compensate temperature variation across the width of strip. Comparing with parallel type slot nozzle, it can adjust temperature distribution along the roll width continuously by adopting proper concave curves, which is more flexible than rectification boards delivery system. Strips of magnesium alloy AZ31 were produced in the pilot caster with the concave slot nozzle. The experiments show that surface quality of as cast strip was improved by using the new type of nozzle.

Simulation of Inelastic Deformation and Thermal Mechanical Stresses in Twin-Roll Casting Process of Mg Alloy

2007 ◽  
Vol 340-341 ◽  
pp. 877-882
Author(s):  
Xiao Dong Hu ◽  
Dong Ying Ju
Keyword(s):  
Casting Process ◽  
Rolling Process ◽  
Mechanical Stresses ◽  
Slip Zone ◽  
Thin Strip ◽  
Small Displacement ◽  
Thermal Flow ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

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.

Study on Molten Zone in Twin-Roll Casting of Magnesium Alloy Strip

2013 ◽  
Vol 395-396 ◽  
pp. 209-213
Author(s):  
Zhi Pu Pei ◽  
Hong Yang Zhao ◽  
Xiao Dong Hu ◽  
Dong Ying Ju
Keyword(s):  
Magnesium Alloy ◽  
Molten Pool ◽  
Casting Process ◽  
Solidification Structure ◽  
Molten Zone ◽  
Deformation Bands ◽  
Twin Roll Casting ◽  
Structure Changes ◽  
Roll Casting ◽  
Twin Roll

Thermal flow finite element simulation was carried out to deeply understand the solidification and deformation phenomena of magnesium alloy in molten zone during twin-roll casting process. The results show that temperature near the nip of the rolls is about 680K based on current conditions, and there are two vortexes in the molten pool during casting, a peak formed at solidus. Due to the metal flows in molten pool and relative rotates of the rolls, temperature field of molten zone is different from normal casting, which will cause the solidification structure changes. An experiment by using a vertical type twin-roll caster was also conducted, and the amount of deformation bands at the joint line is larger than that at the two sides. Substructures can be found due to dynamic recrystallization during casting process.

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