RU2404018C2 - Method of producing continuous section-shaped billet from thermit steel - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: proposed method comprises continuous feed of rod from compacted mix material into iron receiver, said mix material having the density of 3300-4500 kg/m³, producing thermit steel melt bi firing aforesaid rod and feeding produced melt from iron receiver into profiling crystalliser. Then forming of continuous section-shaped billet of produced.

EFFECT: producing section-shaped billet with preset mechanical properties and structure.

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Description

The method relates to metallurgical production, in particular to methods for producing a continuous steel profile, and can be used in metallurgy.

A known method of producing steel by reduction from scale, used in the technology of thermite welding, in which the connected ends of the parts, installed with a certain gap, is molded with a refractory mass and heated. A thermite mixture of aluminum powder and scale (Fe ₃ O ₄ ) containing at least 25% O and 70% Fe is filled with a crucible located above the mold. The termite is ignited in the crucible by an arc, a special fuse, or thermal matches; the commenced combustion proceeds quickly, spreading over the entire volume of the thermite mixture within a few seconds, and proceeds according to the reaction

3Fe ₃ O ₄ + 8Al + 4Al ₂ O ₃ + 9Fe.

After the end of the redox reaction in the crucible and some exposure, the termite metal is released from the crucible and poured into the inter-joint space. After a few hours, the sprues are removed and cut down and the sprues are arrived [Welding in mechanical engineering. Reference book in 4 volumes / Editorial: G.A. Nikolayev (previous) and others - M .: Mechanical Engineering, 1978.V.1. / Ed. N.A. Olshansky. 1978. 504 p., Ill., See p. 477].

The implementation of the method allows the rational use of iron oxide, which is a technological waste of metallurgical production, to obtain metal products of large cross section.

However, the considered method has several disadvantages. The process of obtaining a steel product is energy-intensive, periodic, therefore, the productivity is low, it is impossible to obtain a continuous profile metal product.

The closest in technical essence and the achieved result is the method used in the device for continuous horizontal casting [Special casting methods: Reference. / V.A. Efimov, G.A. Anisovich, V.N. Babich and others. Under the general. ed. V.A. Efimova. - M.: Mechanical Engineering, 1991. - See p. 500]. The production of metal using this device is as follows: the melt is poured into a metal receiver, from which it enters the cavity of the cooled mold and solidifies, forming metal, which is cyclically removed from the mold by a tightening device.

The considered method has several disadvantages. During the implementation of the process, there is no possibility of continuous production of metal products; the process is characterized by high energy costs for producing a metal melt.

These and other disadvantages are eliminated by the claimed method. The problem solved by the claimed method is the possibility of recycling metal waste from engineering and obtaining a continuous profile billet with a different cross-sectional profile from thermite steel without using the energy-intensive process of furnace remelting of steel components. At the same time, it is possible to obtain a steel melt as a result of an exothermic reduction reaction and to manufacture a continuous profile billet from the melt.

This result is achieved by the fact that in the method for producing a continuous profile billet from thermite steel, including the preparation of a molten metal and the formation of a continuous profile billet, the thermite mixture is preliminarily pressed into a rod with a density of 3300-4500 kg / m ³ , which is continuously fed into the molten metal.

A causal relationship between the essential features and the technical solution achieved is ensured by feeding a pressed thermite rod with a density of 3300-4500 kg / m ³ to the metal receiver, from where the steel melt obtained in the metal receiver through an exothermic reaction enters the profile mold, as a result of which a continuous steel profile blank is formed .

In this case, the possibility of incomplete passage of the redox reaction and the appearance of structural differences in the body of the resulting steel profile is excluded. The efficiency of the process is ensured by the exclusion from the process of producing steel melt of traditional metallurgical furnaces and the absence of the need for additional heating of the steel billet to obtain a continuous steel profile.

Obtaining a termite rod with a density of more than 4500 kg / m ^{3 is} impractical, because such a rod has chipped surfaces resulting from high internal stresses. Obtaining a termite rod by pressing the powder of the termite mixture to a density of 3300 kg / m ^{3 is} impractical due to the low strength of such a rod.

A method of obtaining a continuous billet of thermite steel can be carried out using the installation indicated in the drawing. The drawing shows a installation with a vertical section of the metal receiver.

The implementation of the method is carried out using an installation consisting of a hopper-dispenser 1, in which the fractional thermite material is mixed, a pressing device 2, in the bottom of which there is a calibration hole for the exit of the termite rod 3, the free end of which is immersed in the metal receiver 4, equipped with a dividing wall 5 , letok 6 for downloading slag 7. The metal receiver 4 in the bottom part is equipped with letk 8 for pouring the metal 9 formed as a result of the exothermic reaction, rofiliruyuschy mold 10, from which a continuous steel billet with a cross section defined by the profiling mold. A profile mold can form a profile blank both in the gravitational state and by pressure - rolling or stamping.

A method of obtaining a continuous billet of thermite steel is as follows.

In the bunker-dispenser 1, the components of the termite material are mixed with its dosing into the pressing device 2. The thermite mixture consists of aluminum powder and scale (Fe ₃ O ₄ ) containing at least 25% O and 70% Fe. From the bottom of the pressing device 2, equipped with a reverse for eliminating possible emergency situations, there is a sealed thermite material in the form of a pressed rod 3 with a density of 3900 kg / m ³ cross-section determined by the calibrating hole of the pressing device. The rod 3 from the pressing device 2 is fed with its free end to the metal receiver 4. In the metal receiver 4, the rod 3 from the thermite mixture is ignited with an activator. As an activator of the reaction, an arc, a special fuse, or thermal matches can be used. The combustion process proceeds in the metal receiver 4 quickly, sequentially spreading over the entire volume of the thermite mixture, and passes through the reaction

3Fe ₃ O ₄ + 8Al + 4Al ₂ O ₃ + 9Fe.

The reaction is carried out continuously as the pressed rod is burned from the thermite mixture. The reverse is necessary for the possibility of stopping the process, while you can adjust the feed rate of the rod into the reaction zone. In the process of the termite reaction, slag 7 is formed, which floats in full to the surface of the formed metal 9. Slag is continuously downloaded from the metal receiver through the groove 6, and metal 9 - through the groove 8. The separation wall 5 is installed in the metal receiver 4 to prevent slag mixing 7 s steel melt 9, which, through a groove for downloading the melt of the resulting thermite steel, is continuously supplied to the shaping mold 10. A continuous steel profile blank comes out of the mold 10 and whose cross section profile is defined by the mold at a gravity shaping structure or a workpiece during pressing.

Thus, the proposed method allows to continuously obtain a steel profile of a homogeneous structure without the use of melting furnaces.

The claimed method allows to obtain a continuous profile steel billet with the predicted physical and mechanical properties and structure from metallurgical waste without the use of traditional batch furnaces, which reduces the cost and improves the quality of the steel billet.

Claims (1)

A method for producing a continuous profile billet from thermite steel, which includes continuously feeding a rod with a density of 3300-4500 kg / m ³ pressed into a metal receiver into a metal receiver, forming a thermite steel melt by igniting the rod, supplying the melt from the metal receiver to a profile mold and forming a continuous profile in it blanks.

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