RU53944U1 - CASTING AND ROLLING COMPLEX OF METALLURGICAL MICROFACTORY - Google Patents

Abstract

The utility model relates to metallurgy, to the technology of manufacturing commercial products from cast and continuously cast billets by remelting charge material based on compacted and / or non-compacted cast iron and / or steel shavings and / or scrap metal. The casting and rolling complex of a metallurgical micro-plant includes technologically interconnected aggregates for smelting an iron-containing melt, made in the form of technologically interconnected at least one induction furnace 1 and one electric arc furnace 2, an out-of-furnace complex steel processing unit 3 equipped with an autonomous casting machine 18, a steel casting unit on a continuous casting machine 4, a heating unit 5 for rolling, a descaling unit 6, a rough rolling complex 7 and rolling mill complex 8, cooling unit 9 and unit 10 for editing finished products.

Description

The utility model relates to metallurgy, to the technology of manufacturing commercial products on a casting and rolling complex from cast and continuously cast billets by remelting charge material based on compacted and / or non-compacted cast iron and / or steel shavings and / or scrap metal.

Over the past 20 years, metallurgical science has created new, effective technologies, which led to the construction of mini-and micro-factories (MMZ) and foundry-rolling complexes (LPC). USA, about 50% of metal products are produced in mini-factories. In developed countries, they account for at least 40% of rolled metal products. According to forecasts, by 2020 at least 70% of metal products in the world will be produced at mini - and micro plants.

Known casting and rolling complex of a metallurgical micro-plant-timber complex for the production of long products from steel, including a metallurgical module for remelting scrap in the amount of up to 10 thousand tons per year. The metal is remelted in a 6-ton furnace and cast on a single-strand continuous casting machine-continuous casting machine. Then, depending on the assortment obtained, the billets are sent for further processing to a rolling module, which turns the billet into long products of 20-50% smaller diameter. In this case, the billet enters the rolling mill without heating in the furnace, using the heat content of the cast billet [1].

The technology of the well-known timber industry can only be implemented using scrap metal.

As a prototype, a casting and rolling complex-LPK of a metallurgical micro-plant was adopted, including units for steel smelting, out-of-furnace steel processing, steel casting on a continuous casting machine-continuous casting machine, heating for rolling, sintering before rolling, roughing and finishing rolling complex of a small section mill, unit cooling and editing of finished products [2].

The prototype LPK has the same disadvantages as the known analogues, i.e. with its high productivity, the technological capabilities of the timber processing complex are limited, since it can be implemented only for the production of rolled steel in bars and only based on the remelting of scrap metal.

The claimed technical solution is based on the expansion of technological capabilities by remelting compacted and / or non-compacted cast iron and / or steel shavings and / or scrap metal and independently obtaining marketable products at various technological stages: smelting and production of commercial cast iron

in ingots and steel in the form of a continuously cast billet. The new technology is less costly and more environmentally friendly than the known ones.

The technical result obtained when solving the problem is manifested in the possibility of obtaining marketable products at various technological stages: smelting and production of commercial iron and steel by controlling the technological regulation of the modules from which the timber complex is built.

The task is achieved by the fact that in the casting and rolling complex of a metallurgical micro-plant, which includes units for smelting iron-containing melt, out-of-furnace steel processing, steel casting on a continuous casting machine, heating for rolling, descaling, roughing and finishing rolling complex, cooling and dressing unit for finished rolled, according to the utility model, the smelting unit is made in the form of technologically interconnected at least one induction furnace and one electric arc furnace, and the casting unit on a continuous billet casting machine is configured to simultaneously continuously cast billets of equal cross-sections of square and / or round profile, while the heating unit for rolling is made two-module: induction furnace gas-flame furnace; and the rolling complex includes technologically interconnected roughing stands of a pre-deformation mill, a cross-helical rolling mill and a wire mill.

Structurally, in the casting and rolling complex, the continuous casting machine would be equipped with a set of interchangeable molds for the continuous casting of round and / or square billets with equal cross-sectional areas.

For a better understanding, the invention is illustrated in the drawing, where

Figure 1 - General flowchart of the casting and rolling complex of a metallurgical micro plant;

Figure 2 is a differential process diagram of a casting and rolling complex of a metallurgical micro-plant;

Figure 3 is a fragment of a continuous casting machine with replaceable molds.

The casting and rolling complex of the metallurgical micro-plant, figure 1 includes technologically interconnected automatic control system units for smelting iron-containing melt, after-furnace treatment of steel, made in the form of technologically interconnected at least one induction furnace 1 and one electric arc furnace 2, unit 3 out-of-furnace complex processing of steel-AKOS for its refining and refinement by chemical composition and temperature, equipped with

autonomous machine for continuous casting of billets 4, a unit for heating billets for rolling 5, a unit for descaling 6, a rough rolling complex 7 and a finishing rolling complex 8, a cooling unit for rolling 9 and a unit 10 for editing finished products.

The drawing of Fig 2 shows a more detailed layout of the inventive casting and rolling complex.

The heating unit 5 for rolling in FIG. 2 is made two-module: a gas-flame furnace 11 or an induction furnace 12 (a specialized inductor for heating can be used); while the draft rolling complex 7 and the finishing rolling complex 8 may include technologically related modules of the roughing stands 13 of the rough rolling complex 7 and the modules of the finishing rolling complex 8, consisting of universal finishing stands 14 and cross-helical rolling mills 15 and, further, the wire mill 16.

In the casting and rolling complex, the smelting unit of the electric arc furnace 2 can be equipped with a means 17 for inert gas purging of the steel melt in the electric arc furnace. Obtaining commercial pig iron in ingots is provided by casting molten iron from an induction furnace 1 on a casting machine 18.

The machine of FIG. 3, steel casting - continuous billet casting machine 4 is equipped with a set of interchangeable molds 20 for continuous casting of billets; it is equipped with a set of interchangeable crystallizers for continuous casting of billets 21 round and / or billets 22 of square profiles with equal cross-sectional areas.

Depending on the technological needs, on a machine 4 for continuous casting of billets, it is possible to pour simultaneously or separately billets 21 of round and / or billets 22 of square profiles.

Example. Description of the micro-plant timber processing complex

A feature of the new casting and rolling complex is the ability to independently obtain marketable products at various technological stages: smelting and production of commercial iron and steel, casting of continuously cast billets, production of finished products in bars and riots. In induction melting furnaces 1, using cast iron shavings from the processing of foundry molds as the starting material (MF, chemical composition [C] - 3 ... 3.6%, [Si] - up to 1.5%), liquid cast iron is obtained , which is then poured onto a casting machine 18 into commercial cast iron ingots. Using steel chips, cold or hot-pressed briquettes from steel or cast iron chips, cast iron chips as charge materials, in the induction furnace 1 a liquid melt is obtained, which is then poured into DSP-2, into which up to 40-60% of steel chips are poured onto the bottom and scale. In DSP-2 steel is smelted, which after

refining and finishing on AKOS-3 is poured into a continuous casting machine-4 with a replaceable mold into a square blank and / or a round blank.

Depending on the technological regulations, the new configuration of the micro-plant allows using, for example, two induction furnaces for the direct production of cast iron by remelting cast iron shavings in one of them, followed by casting pig iron into pigs and, in parallel, producing pig iron from the shavings in the second induction furnace for overflowing it scale and steel chips loaded in an electric arc furnace, in which, using the heat content of liquid iron, the steelmaking process takes place with minimal energy consumption. A variant of simultaneous operation of two induction furnaces for the preparation of a liquid intermediate is possible with the aim of finishing it to finished steel in an electric arc furnace or in AKOS. It is possible that one induction furnace replenishes the volume of liquid residue (swamp) on the bottom of the electric arc furnace, and the remaining cast iron is poured on a casting machine. An electric arc furnace with a replenished swamp is refueled with shavings and scale on a swamp, and then a portion of molten iron (steel) from the second induction furnace is poured into it.

Continuously cast billets can be sold as commercial products or sent for subsequent conversion to a rolling modular complex. After heating the continuous continuously cast billets in the inductor 12 (directly after the continuous casting machine or in a flame heating furnace 11 (when using cold billets from the warehouse) and rolling the billets in the crimping stand 7 or on the cross-helical rolling mill 15, the means 19 are cut into measured lengths, its cooling and dressing on the unit 10, resulting in finished products in the form of long products in bars with a diameter of 17-75 mm When using stands in the form of a continuous or linear mill, you can get coal a new profile 25 × 25-40 × 40 mm or channel No. 5-6.5 (13-14 Figure 2). Continuously cast billets rolled on cross-helical rolling mills 15 allows to obtain rolled stock in rods in a wide range of diameters. This technology allows us to further deepen the degree of product processing, for example, adding a wire rolling unit with a cooling line and a coiler, we get the possibility of producing wire rod ⌀5.5-14 mm.

A feature of this technology is the possibility of using 2 molten iron (40 ... 60% of the total amount of the charge) for melting steel in an electric arc steelmaking furnace ( _Tmelt = 1340 ... 1350 ° C), superheated in an induction furnace by 50 ... 70 ° C above liquidus temperature.

In this way

1) cast iron gives part of the heat to the charge (steel shavings, briquettes and scale - 40-60% of the total charge), accelerating the melting process and reducing energy consumption;

2) protects the chips from the direct impact of the arc, which reduces its fumes;

3) is a scaling agent and reducing agent, contributing to the saving of expensive carbon-containing materials.

In DSP-2, liquid metal is intensively mixed by blowing the molten bath with an inert gas, for example, argon, which ultimately allows the melt to be homogeneous in chemical composition and temperature and with a small amount of non-metallic inclusions and gases. After the steel is melted in the chipboard, the metal is poured from the furnace into the ladle and fed to the aggregate 3 of the AKOS steel complex processing, where it is refined and refined in chemical composition. Then, on a continuous casting machine 4 with a replaceable mold, steel is poured into billets, respectively, of square (100 × 100 mm) and / or round (⌀85 mm) sections, which, after cutting and heating in an induction furnace (inductor) 12, are supplied to the hydraulic breaker 6 dross. As a result of subsequent rolling of the billets in the rough rolling complex 7 and in the finishing rolling complex 8 at the mills 13 and in the universal stands 14, shaped rolled products are obtained in the form of a corner and a channel, and when rolled on cross-helical rolling mills 15, round rolling is obtained, which is commercial or rolling for wire mill 16.

Advantages of the modular design of the casting and rolling complex

A feature of this casting and rolling complex is the ability to independently obtain marketable products at various technological stages: on the basis of induction furnaces, using pig-iron shavings as a source material, pig-iron ingots are obtained; using steel chips, cold or hot-pressed briquettes, cast-iron shavings, and scale as batch materials. At a continuous casting machine with a replaceable mold in a square or round cross-section product. After rolling the billets in a roughing stand and on mills with universal stands or on a cross-helical rolling mill, the rolled products are cut into measured lengths, cooled and straightened, as a result of which finished products are obtained (bar, angle, channel, etc.) . Such a technological scheme allows us to further deepen the degree of processing of products. For example, adding a wire mill, we get the ability to produce wire rod ⌀5.5-14 mm.

The new design of metallurgical micro-factories realizes the goal set by the utility model and, in comparison with well-known analogues, allows to achieve:

1) the use of local raw materials; 2) the relatively low cost of construction and quick payback (usually not more than 1.5 years); 3) the ability to use existing production facilities, which significantly reduces the cost of building a micro-plant; 4) the maximum flexibility of the assortment depending on the situation on the market, or independence from price competition in monopolistic production of products with unique properties; 5) the modular principle of organization allows you to quickly build up, rebuild or replicate production.

In a micro-plant, it becomes cost-effective to use less high-quality secondary raw materials, such as shavings, iron-containing sludge and briquettes from them. Therefore, scrap processing companies and large machine-building enterprises are interested in the construction of metal-processing microproduction. These technologies are less costly and more environmentally friendly.

New metallurgical mini-factories technologies allow to increase output per worker up to 1,500 tons per year, i.e. 5-10 times in comparison with traditional metallurgical enterprises. The new generation mini- and micro-factories are environmentally friendly, consume 3-5 times less electricity, have a mass of equipment 50-150 times less, and take up significantly less space. Such a plant-workshop is located on an area of 33 × 125 meters, and it is served by 15 people per shift. The cycle of receiving finished products is reduced by 100 times. Less than 3 hours elapse from filling scrap into the smelting furnace to the shipment of rolled metal.

The novelty of the declared micro-plant is the maximum flexibility in changing its range depending on the situation on the market. The modular principle of creating such a production allows you to quickly build it up and rebuild, or replicate. When the situation on the market changes, it can be quickly transferred to another place.

A typical micro-plant is the use of well-known and proven technologies, a minimum of operations, high automation of processes and the maximum use of the finished infrastructure. Induction furnaces work almost without the burning of iron, i.e. there is no need to build gas purification, which saves significant money, metal waste with carbon waste is eliminated, whereas in smelting in electric arc furnaces, these losses are at least 10%.

Timber industry is technological for the production of bar stock with a diameter of 20-50 mm from special and tool steels. These are, first of all, bars of high-quality carbon steels according to GOST 1050-88, alloy steels according to GOST 4543-71, stamped and tool steels according to GOST 5950-73 and 14959. Chrome can be added to them.

steel (GOST 5632-72); grades of ferritic and martensite-ferrite chromium-nickel austenitic steels, chromium-nickel steels of austenitic-ferritic class.

Industrial use of the claimed facility is expected in the Republic of Belarus.

Information sources:

1. Chigrinov MG, Chigrinov AM, Prutskov M.E. // Production of small continuously cast billets. Moscow, Intermet Engineering, 1998, 127 pp.

2. Sivak B., Protasov A. // Current status and development prospects of mini-factories for the production of long products, Moscow, National Metallurgy, 2002, No. 2, p. 38-46.

Claims (2)

1. The casting and rolling complex of a metallurgical micro-plant, including units for smelting iron-containing melt, out-of-furnace steel processing, steel casting on a continuous casting machine, heating under rolling, hydraulic sintering, roughing and finishing rolling complex, cooling and dressing unit for finished steel, characterized in that the smelting unit is made in the form of technologically interconnected at least one induction furnace and one electric arc furnace, and the casting unit on a continuous casting machine The billets are made with the ability to simultaneously continuously cast billets of equal sections of a square and / or round profile, while the heating unit for rolling is made two-module: an induction furnace is a gas-fired furnace, and the rolling complex includes technologically interconnected roughing stands of a pre-deformation mill, a mill with universal stands, transverse helical rolling mill and wire mill. 2. The casting and rolling complex according to claim 1, characterized in that the steel casting unit on a continuous casting machine is equipped with a set of interchangeable molds for the continuous casting of round and / or square billets with equal cross-sectional areas.