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Abstract

Contents

Introduction

In the context of the global increase in energy prices, the priority of industry is a worldwide introduction of innovative energy-saving technologies that help minimize the share of energy costs in the cost of hire and improve, thus its competitiveness. In the fully specified direction corresponds to the process of casting-rolling roller, whose idea was proposed by Henry Bessemer in 1856 [1-2].

Despite the fact that the technology roll-casting-rolling reached the industrial implementation [3,10], the relevance of studies of this technology is still very high because of its high research intensity, and, to date, not settled some technological elements. Confirmation of this fact may be the fact that the leading research centers in the area of metallurgy have created over the past few years a whole set of laboratory facilities: the Rhine-Westphalian School, Aachen, Institute for the Study of iron to them. Max-Planck equation, Dusseldorf (Germany), University of Oxford (UK), a technological institute, Osaka (Japan) and the Institute of Industrial Materials, Mr. Bouchervil (Canada), etc.

Analysis of the results of scientific work done on these machines, showed that currently remain unresolved or require further study of the following types of questions [9]:

Based on the analysis of structural features known from the literature of experimental machines roll casting-rolling [5,8] can be concluded about the advisability of studying the object in small laboratory settings. According to this was proposed a small laboratory setup for the implementation of process-roll casting-rolling on the alloys with low liquidus temperature.

1. Goal and tasks of the research

The development of constructive, kinematic and hydrodynamic scheme of small laboratory setup for the implementation of process-roll casting-rolling on the alloys with low liquidus temperature.

2. Design of the laboratory facility

In designing the experimental setup used a vertical pattern of the process [4,7] when molten metal is fed from the furnace to the casting bath, and after to the space between rolls, zone of crystallization of the metal, under the action of gravity.

Rolls-molds are composed of water-cooled copper sleeve and two axial inserts that provide the desired character of warm-taking with the inner surface of the tires (Fig. 2). Each cylinder has its own unique DC drive, which ensures the implementation of high torque and the ability to manage the process with the required plastic deformation. In addition, provided the possibility of regulating the distance between the rollers, thus expanding the range of thicknesses studied a finite band: a maximum of 4.0 mm.

Design of the laboratory facility

Figure 1 – The scheme of the node roll-molds (3D model):
1. water-cooled sleeve; 2. oporoa-carts; 3. inner box; 4. pinion gear; 5. driven gear.

The results of the design in the form of 3D models and photos of draft power are shown in Figure 3.

Design of the laboratory facility

Figure 2 – The model projected a laboratory setting process, roll casting-rolling:
a - volume model of the laboratory setup process, roll casting-rolling, where 1 - the drive motors, 2 - spindles, 3 - cylinders, 4 - pinion gear, 5 - driven gear, 6 - bucket filling material, b - photo lab full-scale installation.

Specifications made in the laboratory setting of the filling stand are presented in Table 1:

Design of the laboratory facility

Table 1 – Main characteristics of the designed experimental set-roll casting process of rolling

3. Creating a mathematical model

Additionally, in parallel with the creation of a physical model was developed mathematical model allowing to study the process of casting a variety of materials for the above installation. The model is implemented in the software package ANSYS [6].

For the mathematical modeling of roll casting-rolling was selected generic software package ANSYS Int., Which is used to solve the problems associated with many branches of science and technology, such electrical engineering, electromagnetism, hydrodynamics, gas dynamics, etc.

Creating a mathematical model to study the processes of mixing and solidification of molten metal strip at the roll casting was carried out in an environment ANSYS CFX, has the following features:

The basis of the developed mathematical model is a solution using the finite element method of unsteady heat conduction basic equation :

Creating a mathematical model

And Navier-Stokes equations, which include:

The solution of problems of fluid flow and solidification was realized in three-dimensional interpretation, with the following assumptions: non-deformable rolls, during the turbulent melt on contact between the roller and the metal holds a permanent adhesion.

As the spilled metal was chosen as lead. The boundary conditions are: thermal conductivity - 23.2 W / (m • K), specific heat capacity of spilled metal - 138.84 J / (kg • K), the density of the spilled metal - 10 641 kg / m 3. The technological characteristics are taken as close to the capabilities of the laboratory setup: external rotor diameter - 76 mm, the length of the zone of crystallization-deformation - 40 mm, strip thickness - 3.25 mm, the initial temperature of the molten metal - 327 ° C, constant spilled metal.

Output

Based on the analysis of designs available laboratory facilities designed version of a small laboratory device designed to study the hydrodynamics of the melt stream and optimize a number of technological parameters. The results of the primary mathematical modeling for the technical characteristics of the facility showed that it allows a wide range of modeling materials with a sufficiently low temperature crystallization.

References

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  2. Степанов, А. H. Производство листа из расплава /А. И. Степанов, Ю. В. 3ильберг, А. А. Неуструев. - М.: Металлургия, 1978. - 160с.
  3. Schueren, V. The Castrip Process - an Update on Process Development at Nucor Steel’s First Commercial Strip Casting Facility / V. Schueren, P. Cambell, W. Blejde // Iron & Steel Technology.-2008.-July.-C.64-70.
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