Home Natural farming Layout of equipment for mill 450. Large-section mills. cold cutting scissors

Natural farming

Layout of equipment for mill 450. Large-section mills. cold cutting scissors

Rolling mill

Fig.2

I - stock warehouse; II - separation of heating furnaces; III - deadlift span; IV - scrap span; V - machine room; VI - finished products warehouse;

1 - heating furnaces; 2 - scissors; 3 - roughing group of stands;

4 - flying emergency scissors; 5 - finishing group of stands; 6 - flying scissors; 7 - refrigerator; 8 - finishing area

Depending on their purpose, rolling mills can be divided into two groups:

1) mills for the production of intermediate products;

2) mills for the production of finished products. The first group includes blooming and continuous billet mills that supply semi-products for the production of long steel, as well as blooming and slab mills that supply semi-products for the production of sheet steel. Bloomings and slabs are large crimping mills with rollers with a diameter of 800-1500 mm. The main direction in the development of these mills is to increase productivity primarily by increasing the mass of ingots, which when rolling slabs reaches 50 tons. The development of blooming and slabs was also accompanied by an increase in the cross-section of the produced semi-product, an increase in the power of the main engines of the mills, and mechanization and automation of auxiliary operations. Most widespread received single-stand reversible blooming and slabs with rolls with a diameter of 1150-1300 mm.

A modern billet mill is a continuous mill installed behind the blooming mill. Previously, 12 stands of a continuous billet mill were installed in two groups of six stands each (Fig. 6). The main changes in the technology and equipment of these mills recently are the abandonment of strip turning and an increase in the size of the initial blooms and final blanks. Due to this characteristic features Modern continuous billet mills consist of alternating stands with horizontal and vertical bars and individual drive of the rolls of each stand with speed control. The latter provides control of the rolling speed, simplifies the setup and calibration of the rolls. In order to increase the cross-section of the blooms entering the flocks, the modern continuous billet mill consists of 14 stands, with the first group consisting of eight and the second group of six stands. Increasing the size of the initial blooms and final blanks requires the installation of mills with larger diameter rolls and engines with greater total power.

In the cold rolling shop for electrical steels (Fig. 3), the alternation of spans is provided in the following sequence: a span of the pickling department without increased heat generation, a span of continuous annealing units, a span of the rolling department, machine rooms, a span of continuous annealing units and bell-type furnaces, a span of the finishing department. The courtyards of these buildings are located either parallel or at an angle of 0-45 0 to the direction of the prevailing winds with the open part of the courtyard oriented to the windward side. To ensure normal operation of the aeration lantern, the longitudinal axis of the latter must make an angle of 60-90° with the direction of the prevailing wind. The main sources of heat generation are located directly under the lantern. Heating devices and furnaces for heat treatment of metal are placed at such distances that the heat flows from them do not cross.

Fig 3.

I - pickling department; II - separation of continuous annealing units; III - cold rolling department; IV - department of bell-type annealing furnaces; V - finishing department; 1 - boiler room; 2 - conveyor of hot-rolled rolls; 3 - warehouse of hot-rolled coils; 4 - continuous pickling units; 5 - installation for heating mother liquors; 6 - cross-cutting unit; 7, 9, 10, 20, 23 - racks for installing rolls; 8 - transfer trolley; 9 - roll grinding workshop; 12 - slitting units; 13 - reversible quarto mill; 14 - continuous five-stand mill; 15 - compartment for preparing the coating; 16 - protective coating units; 17 - electric furnaces OKB-4006; 18 - mechanical repair shop; 19 - machine room No. 1; 21,22 - workshop for inspection of rolling bearings and fluid friction; 24,25 - transfer conveyors; 26 - OKB-4017 electric furnaces; 27 - cleaning and washing units; 28 - straightening machine; 29 - guillotine shears; 31 - space for packing packs; 32 - loading ramp; 33 - finished products warehouse; 34 - continuous strip annealing and tempering units; 35 - twenty-roll mill.

Continuous Large Section Mill 450 designs of VNIImetmash, EZTM and UZTM with a design capacity of 1.5 million tons/year were first installed and have been successfully operating since 1975 at the West Siberian Metallurgical Plant.

In terms of equipment composition, stand arrangement and technological process, rolling mill 450 is unique in world practice.

Mill range: round steel with a diameter of 32-60 mm; square 30-53 mm; angular equal-flange (75Х Х75) - (125X125) mm, angular unequal-flange of equivalent section; rolled profiles according to special specifications: lightweight I-beams (thin-walled) No. 16-30; normal I-beams with parallel flange edges No. 16-30; normal channels with parallel flange edges No. 16-30; rolled profiles in accordance with GOST 8239-72 and GOST 8240-72 I-beams and normal channels No. 10-18; steel strip (9-22) X (125-299) mm.

The initial blanks of square and rectangular sections are: 150X150; 135X200; 150X200; 160Х Х270 mm; length of the workpiece is within 4-12 m, weight 0.7-4.7 tons.

Two heating furnaces are installed at the mill, with space left for a third furnace. The roughing group of stands consists of three groups, three stands in each, of which: the outer stands with horizontal rolls, the middle (the so-called combined) can work with rolls installed both horizontally and vertical position. The distance between continuous groups of stands is taken differentially, taking into account the maximum length of the roll from the entire range of rolled profiles, so that the strip comes out freely and is located between the continuous groups of stands. In front of the first three-stand continuous group, scissors are installed for cutting the workpiece to a certain length. The cutting force of the scissors is 400 tf. Before each three-stand continuous roughing group, tilters are provided.

The finishing continuous group consists of seven stands. The stands here are also different in their design and purpose, according to the location of the rolls: I, IV and VI-combined (K), the remaining stands with horizontal rolls and universal (G, U). They compress the flanges of I-beams and channels and ensure parallelism of the edges. Flying shears with a cutting force of 130 tf are installed in front of the finishing group of stands, and after the finishing group - with a cutting force of 63 tf.

To cool the finished profile rolls, a double-sided refrigerator is installed, and each section (side) of the refrigerator can work independently.

Rolling speed on the mill is 4-12 m/s; average productivity depending on the profile is 180-300 t/h.

Such high rolling speed and productivity, and the complex range of the mill determined the composition of the auxiliary equipment after the refrigerator. On each side of the refrigerator there are two lines of outlet roller conveyors, on each of them two units of the same type are installed: two roller straightening machines (one in operation, the other in reserve), two cold cutting shears (one in operation, the other in reserve ).

For additional processing of the finished profile, cold cutting scissors, collecting pockets, gratings, machines for tying bags and other auxiliary equipment are used.

Let's consider the operation of the equipment of the large-section mill 450 along the way technological process rolling and its characteristics.

The billet can be fed to the mill in a cold state or preheated, which is determined by the grade of steel. If it is necessary to roll a given profile from alloy or high-carbon steel, then the workpiece is first slowly heated in preheating furnaces to 300-800 ° C. Then it is transferred through a refrigerator 1 by transferring schleppers to methodical heating furnaces. Next, the workpiece can be heated intensively in methodical furnaces, without fear of the occurrence of large internal stresses, to the required delivery temperature. If the workpiece has been processed (surface defects have been removed and it has been cooled), it is placed on loading racks and then transported to heating furnaces.

Provision is made for weighing the incoming batch of workpieces and each workpiece separately. Heating of the metal is carried out in three-zone methodical furnaces operating at gas fuel

with the end task and delivery of workpieces.

Bottom - with walking beams. The furnace can operate as a double-row (with a workpiece length from 4 to 6 m) and as a single-row (with a workpiece length over 6 m). The furnace charge when the workpieces are arranged on the hearth with a pitch of 400 mm is approximately 68 workpieces weighing 320 tons.

The heated billet, piece by piece, according to the rolling rhythm, is issued from the furnace using a machine, placed on a pre-heating roller table and transported to the first continuous group of roughing stands.

If a defect in the front or rear ends of the workpiece is detected, it becomes necessary to cut it into pieces; scissors are put into operation.

In roughing continuous groups of stands, combined stands can also operate with horizontal rolls, which is determined by the calibration and rolling scheme of a given profile.

The rolled products are fed to a double-sided refrigerator 120 m long with an adjustable step of transferring the cooled strips and a device that ensures that two strips with specified distances between them are issued simultaneously to any of the two outgoing roller conveyors, which makes it possible to divide the single metal flow up to the refrigerator into four parallel flows of finished rolled products. .

After cooling in the refrigerator, the rolls undergo technological operations: straightening, cutting to lengths, packaging, tying bags, weighing and storage.

The equipment is designed for increased mechanical properties of metal. Thus, the strength of metal subjected to cold straightening is taken to be 100 kgf/mm2.

Installed eight correct machines 7X630 for straightening shaped and round profiles operate in start-up mode: input speed 1.4 m/s, straightening speed adjustable within 2-6 m/s.

Four cold shears with a cutting force of 630 tf with a knife length of 1000 mm and a knife stroke of 240 mm are designed for 360 cuts per hour with a normal cycle between cuts of 10 s.

The finishing equipment in the flow includes two inspection racks for strips up to 25 m long and two for strips of short length. These racks are designed to further highlight and inspect individual strips that show signs of defect.

Eight baling devices were installed, including two sections 12 m long, designed for strips 6-12-24 m long. The diameter of the package is 250-500 mm. 32 bag-knitting machines were installed for tying bags; weighing is carried out on 16 scales, designed for strips of length: 12-24 and 6-12 m. The division price on the scales is 10 kg. Weighing cycle 10 s.

In addition, the mill is serviced by installations for longitudinal straightening of individual strips and for straightening and cutting profiles of large sections with a straightening accuracy of 1 mm/m.

The operation of the equipment and the execution of technological operations are maximally automated, which eliminates the use manual labor, stabilizes the rhythm of work of the entire mill.

If on operating sectional mills the bottleneck is usually finishing and adjusting operations, then on the 450 mill they are maximally mechanized. At the same time, units for removing defective metal remove rejected strips from the flow without disturbing the main rhythm of metal movement. High-performance units for in-line batching of long rolled sections ensure the alignment of the ends before dropping each strip into a pocket, and carry out the forming and tying of packages with a continuous supply of metal. The shaped steel tilters ensure the supply of the strip to the stacker table in a strictly oriented position, as well as variable orientation of the corner steel with the laying of the strips in a “lock”. Stackers for shaped steel make it possible to bundle strips without pauses in the supply of metal and to bundle finished packages with machines. There are transporters for packages of finished products, operating on an automatic cycle and ensuring the supply of packages to scales and storage devices without cranes. Separately installed units for piece-by-piece metal sorting, cutting and sanding strip stripping units operate.

At this mill, the mass of technological equipment with spare adjacent parts of the mill itself, including equipment for heating furnaces, is 13,282 tons; in the metal finishing and cleaning area, the mass of installed equipment is 9829 tons. The power of the main drives of the mill is 32000 kW.

The area of the entire workshop consists of the area of the mill itself (39,792 m2) and the metal finishing and cleaning area (62,280 m2). The area for storing metal is 6600 m2, taking into account a possible three-day supply in the finished product workshop. The mill is served by 854 people, of which 778 are workers. With a mill productivity of 1.5 million tons/year, output per worker will be 1928 tons/person per year.

The mill's productivity according to the accepted assortment is designed for an equipment load of 81%. Of course, more complete mastery of the installed unique equipment will increase the productivity of the mill and bring it to 1.6-1.7 million tons/year.

As part of the technical and economic indicators, one should highlight the reduction in the consumption coefficient for the established assortment from 1.040 to 1.028 (mill

Mill 450 was designed as an endless rolling mill and provided for welding of workpieces in a stream. However, there are no reliably operating movable butt welding machines yet, so the 450 mill operates with separate rolling of workpieces.

Its history begins on August 8, 1934, with the commissioning of the “500” medium-grade mill. The launch of the first rolling mill meant that MMK became an enterprise with a complete metallurgical cycle, since it had a rolling stage. On May 3, 1935, the "300" mill No. 1 was put into operation. On February 5, 1938, the "300" mill No. 3 was put into operation. In July 1942, all three mills were combined into a single shop - section rolling. Engineer Laur K., who worked in this position until 1949, was appointed his chief.

During the Great Patriotic War, the workshop mainly fulfilled military orders, especially a lot of projectile steel was produced. For the successful completion of front-line orders, the SPC team was repeatedly awarded the Challenge Red Banner of the State Defense Committee. In the third quarter of 1945, by decision of the State Defense Committee, this banner was transferred to the workshop staff for eternal storage. With the beginning of the war, 130 long-rolling workers were mobilized from the workshop to the front, 40 of them died on the battlefields. In 1947, mill "300" No. 3 became the first comprehensively automated mill in the industry. For the successful implementation of this major technical event, specialists K. Laur and V. Sindin were awarded the State (Stalin) Prize.

Since 1960, a program of reconstruction and modernization of equipment has been carried out at all mills of the workshop. As a result of its implementation, roller tables and straightening machines were replaced at the mills, exhausters were installed on heating furnaces and pushers of steel billets were replaced, and lifting tables were eliminated. Outdated saws for cutting hot metal and cold shears on the 500 mill have been replaced with new, more productive ones. More powerful domestically produced motors are installed instead of the old rolling stand drives.

The first uncontrolled silicon rectifiers at MMK, high-power thyristor converters - 10 thousand A to power the rolling stand motors - were introduced into the SPC. Knitting machines for tying bundles of rolled metal products have been developed and implemented at all mills. At the adjustage workshop, overhead cranes are equipped with ring grippers for transporting bundles of metal. The implementation of this entire program made it possible to triple the design capacity of all three SPC mills.

In 1996, mill "300" No. 3 was taken out of operation as obsolete and ineffective. In 1999, the old equipment was dismantled and a new mill was installed in the mill premises. In July 1995, by order of the General Director of OJSC MMK, the SPC was merged with the wire-strip plant and began to be called high-quality.

The section rolling shop operates as part of a medium-section mill "450" and a small-section mill "320" and produces long products of round profiles with a diameter of 11 to 110 mm, hexagonal profiles with sizes from 12 to 75 mm, square profiles with sizes from 55 to 90 mm and reinforcing steel with a diameter of from 12 to 28 and 40 mm. The mills were put into operation in 1904.

At the 320 mill, a rack-and-pinion cooler was put into operation in 1997, which currently allows the plant to produce reinforcing and section steel up to 11.7 m long (along the length of the car).

Section mill 170, 370, 450 of the Long Section Shop of OJSC MMK produces finished products of high quality. The products of section mills are in high demand on the market. The range of products is very diverse and varies depending on orders and consumer needs. The manufactured products meet all quality criteria. Equipment downtime and increased transshipment time lead to large material losses from unproduced products.

Reducing the time required to switch from production of one product range to another allows increasing the productivity of mills. To speed up the process of setting up stands for a specific assortment, the Italian company DANIELI developed a mechanism and algorithm for automatic positioning of the roll gap. This auto-positioning system ensures automatic setting of the inter-roll gap of the rolling stands of the mill in accordance with the technological rolling charts entered into OWS. In addition to the operator entering the required stand clearance values, the operator must enter the exact diameter of the rolls in each stand in OWS. Thus, it was not possible to completely eliminate the human factor when adjusting the gaps, since the maintenance personnel need to accurately measure the diameters of the rolls and enter this data into the gap regulation system; in the case of inaccurate measurement of the diameter of the rolls, an error is introduced into the system for calculating the inter-roll gap, which will not allow precise adjustment of roll gaps.

Long products are used in various industries, both in agriculture and in construction. Without the use of rolled metal, the full functioning of a number of industries is impossible. The development of industry and an increase in the pace of construction requires an increase in the production of rolled metal. The most common products are long rolled products: beams and railway rails, channels, wire rods, various metal profiles, and fittings.

The standard length of long products is from 6 to 12 meters.

The workshop also produces hollow rolled products of round and hexagonal cross-sections with a round axial channel for drilling tools and shafts of submersible electric motors (SEM). Main tasks of the workshop:

Production of long products;

Production of rolling stock for the calibration shop.

The continuous section rolling mill is designed for rolling small and medium-sized products of the following range:

Hot-rolled round steel with a diameter from 14 to 50 mm; (Fig. 11.a)

Hot-rolled reinforcing steel from 8 to 32 mm; (Fig. 11.b)

Hot-rolled square steel with a square side from 12 to 40 mm; (Fig. 11., c)

Rolled angular equal flange steel, profile numbers from 32 to 63 mm;

Rolled angular steel unequal, profile numbers from 45 to 80 mm;

Steel strip with a width of 40 to 90 mm;

Steel channel 50 mm, 65 mm, 80 mm;

Steel brand 50 mm, 80 mm.

The starting material for the section rolling mill is a square billet (bloom) made from mild and semi-quiet, low-alloy and alloy steel grades.

After rolling in the finishing line of the mill, the rods enter the heat treatment system, where heat strengthening is carried out due to the sharp cooling of the rolled metal with water supplied under pressure. There are devices for cutting rolled products into cut lengths and automated packaging of finished products.

A. b. V.

G. d. e.

Fig. 11. Products of the Long Rolling Shop

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Ministry of Education of the Russian Federation

GOU VPO "Ural State Technical University- UPI"

about technological practice

at JSC Metallurgical Plant named after. A.K. Serov"

Student Mayevskaya Ksenia Sergeevna

Specialty "Economics and Enterprise Management"

Head of practice:

Chief calibrator of the plant ________A.V. Semkov

Head of practice USTU-UPI ________S.V. Dudina

Serov 2008

1. Information about JSC Metallurgical Plant named after. A.K. Serov", its products, production structure, development dynamics

2. Technical characteristics of the main equipment of rolling shops

2.1 Large section workshop

2.2 Section rolling shop

2.2.1 Methodical heating furnaces of mills

2.2.2 Stan 450

2.2.3 Stan 320

2.2.4 Adjustage

3. Description of the technological process in the rolling shops of the plant

3.1 Large section workshop

3.2 Section rolling shop

4. Characteristics of raw materials, fuel, basic materials

5. Regime parameters of the technological process for the production of rolled products

5.1 Large section workshop

5.2 Section rolling shop

6. Safety conditions, labor protection in rolling production

7. Characteristics of production waste, atmospheric emissions,

environmental friendliness of production

1. Information about JSC Metallurgical Plant named after. A.K. Serov",

its products, production structure, development dynamics

OJSC Metallurgical Plant named after. A.K. Serova" (formerly the Nadezhda Steel Rail Plant) was put into operation in 1896 and is one of the oldest metallurgical plants with a full metallurgical cycle in the Urals and in Russia. All its equipment was manufactured by companies in Germany, France, and Belgium.

In the production of charcoal cast iron it was a competitor to the Swedish charcoal metallurgy, and in terms of total production it accounted for about a quarter of all metal production in the Urals. In 1899, the plant already had 4 blast furnaces, 4 open-hearth furnaces, a 750 mm trio rolling mill, silica and fireclay brick factories, a forge, and a gas-electric workshop. In 1906, a section rolling shop was built, consisting of two mills: 450 mm and 320 mm for rolling long products and sheet metal, as well as a sheet rolling shop with 11 rolling stands for rolling roofing iron from sheet metal. In 1912, an 850 mm duo mill was installed (instead of a 750 mm mill) with an engine - a steam engine with a power of 10 thousand hp, and a forging and mechanical shop was built.

The main products of the plant were wide and narrow gauge railway rails, roofing iron, shell blanks, long iron, as well as the production of refractory products, silica and fireclay bricks, siphon supplies for the plant’s own needs. In 1931, the production of roofing iron and rails ceased. The rolling of round and square billets of different sections, round and hexagonal rolled products from low and medium alloy steel grades begins. In 1932, for the first time in the world, rolling was mastered on a linear mill. very complex profile- tractor shoe for tracks of tractors and tanks.

Also, for the first time in the world, universal roll calibration was developed and implemented for all three mills (850, 450 and 320), which opened up huge reserves for rolling production. In 1933, the construction of a cold steel drawing shop began and was completed in 1935, which became the largest workshop in the country and ranked second in capacity in the world. During these same years, the plant mastered the production of ball bearing steel and drilling hollow steel. During the war years, the plant produced over 100 different grades of high-quality alloy steel. For the first time in the history of blast furnaces, ferrochrome smelting has been mastered in blast furnaces. In 1944-1945, ferrosilicon was smelted in blast furnaces. During the war years, the plant's output of steel and rolled products increased by 1.7 times compared to pre-war.

Built and equipped in late XIX century by last word technology of that time, today the predominant part of production is carried out using extremely worn-out equipment and outdated ineffective technologies.

The development of the plant until the nineties was characterized by an increase in production volumes due to partial reconstructions, improvements without a radical replacement of main equipment and production technology.

To date, the plant has identified and is preparing the following immediate development prospects: installation and development of a ladle furnace, a vacuum degasser of the VD/VOD type, a continuous casting machine (CCM), expansion of steel production using the electric furnace method. A radical change in the technology of smelting, casting and processing of steel should significantly increase the yield of steel, reduce consumption during casting and then waste, improve the quality of steel and, as a result, reduce the cost of producing finished products.

At the same time, it is necessary to radically modernize the rolling production and finishing of rolled products.

To ensure competitiveness, survival of the plant, the most urgent task Now there is a comprehensive, consistent re-equipment of its production with the most advanced technologies and equipment for the production of high-quality and special steels in a wide range of grades and in a wide range of rolled profile sizes with the most progressive quality characteristics.

At the same time, the cost of production per unit of product must be reduced many times over, both in terms of metal, fuel, energy consumption, and most other factors.

Table 1. - Products manufactured by the plant (product range)

No.	Name	Characteristics (dimensions)	Note
	Agglomerate

	Open hearth steel
	Square blank for rolling		needed by the plant
	Hot-rolled bars
	round - pipe blank		can be supplied with turning
	round large-grade	160-270 mm, 280 mm
	square large-grade
	round small-medium grade
	hexagonal small-medium grade
	drill hollow steel with two grooves	diameter 32 mm
	hollow drill steel round	diameter 32 mm
	hexagonal drill steel		with thermomechanical hardening
	Rolled calibrated

	hexagonal section
	round section with special surface finishing

table 2. - Dynamics of output of main types of products, tons

No.	Name of product	1999	year 2000	year 2001
	Agglomerate

	Open hearth steel
	Rolled bars
	Calibrated steel, including:

	carbon
	automatic

Diagram 1

1 - agglomerate;

2 - open hearth steel;

3 - long rolled products;

5 - calibrated steel.

Products of JSC Metallurgical Plant named after. A.K. Serov" is also exported.

Table 3 . - Export dynamics, thousand tons

Product type	1998	1999	year 2000	year 2001
Blank

Table 4 . - Structure of exports of long products in 2001

A country	Supply volume
	tons	thousand US dollars



Germany


Great Britain
Kazakhstan




Total:

The structure of OJSC Metallurgical Plant named after. A.K. Serova" includes the Turinsky mine, sinter plant, blast furnace shop, open-hearth shop, mills 850, 450 and 320, calibration shop with two departments. Auxiliary workshops: railway, motor transport, gas, power plant, mechanical, foundry and some others.

Turinsky mine contains

b the Kapitalnaya mine, 587 m deep, with a raw ore mining capacity of 230 thousand tons per year;

b processing plant with a capacity of 500 thousand tons of processed ore per year.

Manufactured products are iron and copper concentrates.

Reconstruction is required when production volumes increase or maintenance of equipment in working order while maintaining the volume and quality of existing production.

Sinter plant contains two agglomerates:

b No. 1 sintering area 30 m2 (preserved);

b No. 2 with a sintering area of 50 m2.

Reconstruction with a gas purification installation is required in order to reduce environmentally harmful emissions and improve the quality of the sinter.

Blast furnace shop consists of 3 blast furnaces:

b No. 1 with a volume of 260 m 3;

b No. 3 with a volume of 205 m 3;

b No. 5 with a volume of 212 m 3;

It is necessary to maintain the furnaces in working condition with the reconstruction of the coke warehouse and ore yard. Modernization of the foundry yard is also necessary.

Open Hearth Shop includes 4 open-hearth furnaces with a capacity of 180 tons each with a main lining, operating in the scrap ore process. The first stage of reconstruction of the workshop with a ladle furnace installation for out-of-furnace steel refining was completed.

Currently, the production capacity of the workshop is 580 thousand tons per year. The charge contains about 50% liquid cast iron, supplied in cast iron ladles from the blast furnace shop. When casting steel, 5.6-ton ingots are obtained. The ladle lining is made of fireclay bricks or poured quartzite, the durability of which is 9-11 pours. Blowing imported nitrogen into the liquid metal in the ladle through a gate is carried out in small quantities, since it does not ensure complete mixing of the metal in the ladle. The surface quality of the ingot generally does not meet the requirements for rolling, and to remove defects the ingot must be subjected to cleaning or turning, converting 10-20% of the metal into chips, and also significant cutting of the ends.

Large-grade workshop includes mill 850.

A phased reconstruction of both the mill and the preventative-adjusting equipment and processes is required, linked to the reconstruction of the steelmaking production.

Section rolling shop includes mills 450 and 320.

It is necessary to continue the reconstruction of mill 320 and determine the directions and timing of the reconstruction of mill 450 and areas serving the mills.

Calibration shop consists of two departments in different production buildings, where equipment for heat treatment, cold drawing, turning and polishing of rolled products is installed. Also, a section has been created in the workshop and oil pumping rods are produced using a new special technology - friction welding of the rod with its threaded part and wedge rolling of the connecting parts. In combination with rolling, the technology for producing hollow sucker rods is being developed.

Renewal of some worn-out equipment is required to ensure guaranteed quality.

After the reconstruction of the section rolling shop, it will be necessary to replace equipment to introduce the technology of drawing and turning “from coil to coil” or “from coil to bar.”

Interaction scheme structural divisions plant in the production cycle is shown in Figure 1.

Picture 1

In 1996, the plant was issued a certificate of the Russian Federation, certifying that OJSC Metallurgical Plant named after. A.K. Serov" is part of 5,000 leading enterprises with the status of "Leader" Russian economy" In the same year, the plant was awarded the “International Quality Prize”.

2. Technical characteristics of main equipment

rolling cehowv

The production of hot rolled steel at the plant is carried out in large-section and section rolling shops.

2.1 Large section workshop

The large-section workshop includes mill 850 with sections of heating wells, hot cutting of metal, and slow cooling serving it. For finishing, control, heat treatment, turning, and shipment of rolled products, the workshop has an adjusting department. The equipment location is shown in Figure 2.

Figure 2

mill equipment 850

Heating wells

Type of wells - single-place regenerative. The number of groups is seven. The total number of cells is 165 pieces. Cell cross-section - 900x900 mm, depth - 3000-3300 mm.

Fuel: for I, II, IV, V, VI, VII groups- a mixture of blast furnace and natural gases; in group III - blast furnace gas. All groups of wells, except Group III, equipped with automatic devices for reversing the flame.

Mill 850

Mill type - linear, duo-reversible. Composition: crimping stand (blooming) 900, roughing and finishing stands 850. Drive - group, from the finishing stand side.

The main drive motor - MPS-800-63V4, has the following characteristics:

rated power - 8000 kW;

rated current - 9050 A;

voltage - 930 V;

nominal speed - 65 rpm;

maximum speed - 125 rpm;

armature flywheel moment - 240 t*m 2.

Cage 900 is intended for producing intermediate bars rectangular sections from ingots weighing 4.5-5.6 tons. The type of cage frame is closed. The pressing device is electromechanical. The lifting height of the upper roll is 550 mm. The lifting speed of the upper roll is 2 mm/s. Engine power - 125 kW.

To move the rolls along the roll barrel of the crimping stand, manipulators are installed on the front and rear sides of the stand. The front side manipulator is equipped with a hook-type tilter. The working stroke of the manipulator rulers is 2250 mm. The speed of movement of the rulers is 0.2-1.2 m/s. The length of the rulers is 5000 mm.

The roughing and finishing stands have the same design and are used to produce the finished product from intermediate rolled products. The cage frame type is closed. The pressing device is electromechanical. The lifting height of the upper roll is 250 mm, the lifting speed is 20 mm/min. Engine power - 75 kW. To service the roughing and finishing stands, two mobile roller tables (rolling tables) equipped with tilters are used. Table movement speed is up to 5.9 m/min.

The characteristics of the mill 850 rolls are given in Table 5.

Table 5

Textolite (sliding) bearings are used for rolls in all working stands of the mill. Spring type balancing devices. Cooling of journals, bearings and roll calibers is carried out with water under a pressure of 1.5-2.0 kgf/cm 2.

Hot metal cutting area

Consists of three hot impact cutting circular saws with the following characteristics:

disk diameter - 2010 mm;

disc thickness - 10 mm;

disk rotation speed - 98-100 m/s;

feed speed - 0.03-1.6 m/s.

temperature at the time of cutting - 800-900 o C;

water pressure for cooling the disk is 5-8 kgf/cm2.

Dimensions and profile of cut sections:

square - 130-210 mm;

circle - 140-280 mm.

Delayed cooling section

Characteristics of slow cooling means are given in Table 6.

Table 6

Figure 3 . - Adjustage

2.2 Section rolling shop

The Section Rolling Shop includes two mills (mill 450 - medium-section and mill 320 - small-section), areas - a warehouse for blanks, an adjustage, a warehouse for finished products. The mills and billet warehouse are located in a common two-bay building. Adjustment and warehouse for finished products are located in separate buildings.

2.2.1 Methodical heating furnaces of mills

Purpose - heating of billets before rolling on mills 450 and 320.

Quantity - 3 pcs. (2 - at Stan 450 and 1 - at Stan 320)

Type - methodical, two-row, three-zone, with end loading and issuance of supplies.

Gas curtains are installed in the end window for dispensing blanks; in the loading window there are air bumpers.

The size of the method furnaces is shown in Table 7

Table 7

The monolithic hearth of the simmering zone of the furnaces is made of corundum blocks of the KOR-93 grade. Fuel is natural gas with a calorific value of 7940 kcal/m3. Combustion air is supplied from a VD-12 fan. The recuperator is tubular, single-turn for smoke and three-turn for air. Air heating to 280-320 0 C. Exhaust pipe height, m: for furnaces No. 1 and No. 2 - 60; for furnace No. 3 - 50.

Automatic control systems for furnace operation:

b automatic control of gas and air;

b remote control of the rotary gate;

b remote control of gas and air consumption;

automatic gas safety system.

Methodical furnaces are equipped with loading devices and pushers. Type of loading devices - with walking racks, quantity - 3 pcs. Maximum load capacity of loading devices: on furnaces No. 1 and No. 2 - 40 tons; on furnace No. 3 - 20 tons. Pushers: quantity - 3 pcs. Drive by electric motor type MT-63-10; power - 48 kW; speed -58 rpm. The total force of one pusher is 22200 kg. The length of the pusher path is 800 mm.

2.2.2 Mill 450

The main technological equipment of the mill is located in a building span 30 m wide and 288 m long.

Figure 4 . - Layout of the main technological

mill equipment 450

1 - transfer devices of heated metal to mill 320;

2 - three-roll crimping stand 680;

3 - working line of stands 450;

4 - three-roll calibrating block;

5 - mobile sled saw;

6 - stationary sled saw;

7 - refrigerator section.

Mill type - linear, medium grade. Composition: crimping stand 680, finishing line of four stands, hot cutting and metal cooling section.

Crimping cage 680

Purpose - obtaining intermediate rolls of square and rhombic sections from the original workpiece. Cage type - trio. Type of beds - open, cast. Spring type balancing device. Manual screw pressure device. The cage drive is an electric motor DSP-213-59-16. Engine power - 2000 kW, rpm - 375. Gear cage - type A - 450x450. Gearbox: gear ratio -1-4.96; speed - 75.6 rpm. The characteristics of the rolls are given in Table 8.

A special feature of the equipment of the 680 crimping stand is that the rolls are driven from an electric motor through a gearbox, main clutch, middle shaft of the stand, and a gear stand to the upper and lower rolls of the crimping stand (typical arrangement: motor - gearbox - gear stand - working stand).

To facilitate manual turning and movement of the rolled product from the calibers of the upper horizon to the lower one, “edging” sheets are installed on the front side of the crimping stand 680. To move the rolled product from the lower horizon to the upper one, a lifting and swinging table is installed on the back side of the stand (length - 6000 mm, lifting height - 315 mm, lifting angle - 4 degrees). The roller conveyors of the lifting table (number of rollers - 6 pcs., diameter and length of rollers - 426x2200 mm, roller pitch - 650 mm, speed - 2 m/s) operate reversely. The table is balanced by a counterweight.

Finishing line Mill 450

Designed for pre-finishing and finishing passes when rolling medium-grade profiles. Composition - 4 stands: I-III stands - trio, IV stand - duo. Beds of stands I-III - open type, IV cage - closed. Spring type balancing devices. The drive of the pressing devices is manual. The transfer of rolled material from cage to cage is carried out by means of schleppers, from horizon to horizon - by lifting and swinging tables.

Characteristics of mill 450 finishing line stand rolls are given in Table 8.

Mill finishing line drive: motor type P2-630-202-8SUCHL4, power - 2300 kW, nominal rpm - 290, maximum - 515. Gear ratio - 2.76, gear type - A-160. Gear cage - type A - 450x450, speed - 134 rpm.

Hot calibration stand block 450

Purpose - production of high-precision round and hot-rolled hexagonal products, including hot-calibrated ones (TU 14-1-4542-88).

The block stands are three-roll, of the reducing pipe-rolling type. Quantity - 3 pcs. Roll diameter, nominal - 450 mm. The maximum permissible force on the roll is 24 tf. The maximum torque on the drive shaft is 800 kg/cm. Dimensions of the calibrated rolled profile: for round profiles -30-80 mm; for hexagonal profiles -32-65 mm. Rolling speed - 3.5 m/s. Water consumption for cooling rolls per stand is 100 l/min. Air consumption for engine cooling is 186 m 3 /min.

Using a calibrating block, “precision rolling” is carried out with small compressions of the finished profile of 0.52.5 mm in three-roll calibers.

Section for hot cutting and cooling of metal from mill 450.

Consists of two sled saws for cutting rolled products into bars of the required length in a hot state and slepper coolers.

1. Sled saw (mobile) No. 1. Movement of the sled: minimum speed - 140 mm/s; maximum reverse speed - 280 mm/s. Saw movement: speed - 40 mm/s. The diameter of the cutting discs is 1500 mm. Saw blade speed - 100 m/s. The saw is driven by an electric motor - type A-103-8M. Power - 125 kW. Speed - 730 rpm. Combined gearbox.

2. Sled saw (stationary) No. 2. The technical characteristics are the same as for saw No. 1, except: the speed of movement of the sled is 167 mm/s.

3. Refrigerators of mill 450 are chain, five-strand. Quantity - 2 pcs. Length x width - 7.2x18.4 m. Drive by electric motor: type - MTM-512-8; power - 30 kW; speed - 720 rpm. Rolled products are transported from the refrigerator pockets by an electric overhead crane.

2.2.3 Stan 320

The main technological equipment of the mill is located in the span of the Long Rolling Shop mill building, 27 m wide and 312 m long.

Figure 5 . - Layout of equipment for mill 320

1 - methodical furnace;

2 - crimping stand 550;

3 - lifting and swinging table;

4 - flying scissors;

5 - line of cages 330x750 mm (No. I-VI)

6 - line of frameless stands 330x600 mm (No. VII, VIII);

7 - flying scissors;

8 - accelerated cooling unit;

9 - rack refrigerator;

10 - cold cutting scissors;

11 - assembly pocket;

12 - pre-accelerated cooling line;

13 - continuous (new) finishing group of stands 330x600 (No.IX, X) - not put into operation.

Mill type - linear, small-section. Composition: crimping stand, finishing line of 8 stands, cutting and cooling section for rolled products.

Crimping stand 550

Purpose - compression with a reduction in cross-section and shape change from the original workpiece. Trio cages with open frames. Spring type balancing device. Pressing devices of the upper and lower rolls are screw, manual. Drive of the stand rolls from an electric motor (type - DSP-213-59-16, power - 2000 kW, speed - 375 rpm, gear ratio -3.5, center distance of the gear stand - 575 mm).

The characteristics of the rolls are given in Table 8.

The movement of rolls from caliber to caliber and their tilting from the front side of the crimping stand 550 is carried out using tilting sheets. The movement of rolls from the lower to the upper horizon is carried out using a lifting-oscillating table (the length of the table between 1 and 8 rollers is 5350 mm, the table lift height is 330 mm, the table lift angle is 4 degrees). The table roller conveyor operates reversibly, the table is balanced by a counterweight. Length x diameter of the roller table roller - 1700x426 mm, number of rollers - 8 pcs., speed of the table roller table - 2.4 m/s.

Finishing line of mill 320

Purpose - hot rolling of small-section profiles from rolled products after the crimping stand in preparatory and finishing passes.

Composition: two lines. The first line - 6 stands: I, III-VI stands - variable duo, II stand - trio, stands from a common drive N = 2300 kW. Beds I-VI cages of the closed type. The second line - 2 stands: VII, VIII, each with an individual drive N=500 kW, frameless design of high rigidity. Cage type - NNZhK 320x600 (non-stressed rigid). Characteristics of the rolls of the finishing line of mill 320 are given in Table 8. The transfer of rolled material from stand to stand is carried out using bypass devices.

Before the first stand for tilting and the task of intermediate rolling, a tribe apparatus is installed in the gauge. To turn the rolled stock during the task, an electric turning bushing is installed in stand II.

Drive of the finishing line of mill 320 for stands I-VI from an electric motor: type P2-630-202-8SUHL4, power - 2300 kW, speed (nominal/maximum) - 290/515 rpm.

To cut the ends of the rolled products, hot-drum flying shears are installed behind stand 550 (cutting force - 150 kN, maximum permissible cross-section of the strip to be cut - 1870 mm 2).

Table 8

No.	Mill	Cage	Roll material	Dimensions of the barrel in rough formAndde, mm	Neck sizesthki, mm	Club dimensions, mm
				nominal diAmeter	dlAndon	diAmeter	dlAndon	diameter	dlAndon


			Steel 150Х2ГНМФ
			Cast iron grades SP and SPKHN
		Caliber. block 450	Cast iron brand SP
			Steel 150Х2ГНМФ
			Cast iron grades SP and SPKHN

Section for cutting and cooling of finished rolled products of mill 320

Includes flying shears for hot cutting of rolled products, accelerated cooling units, transport roller tables, a rack cooler with a discharge roller conveyor, cold cutting shears and means of collecting rolled products.

1. Flying scissors. Purpose - cutting hot rolls into lengths of a rack cooler, as well as for cutting the front end of the strip and emergency cutting. The installation location is in the mill flow behind the finishing stand. Type - lever flying “start-stop”. The cut sections are 10-36 mm and equal in area - hexagonal, strip, square corners, etc. The maximum area of the cut section is 1020 mm 2. The temperature of the rolled product is 800-900 o C. The speed of movement of the rolled material during cutting is 2-8 m/sec, the permissible cutting force is no more than 20 kg. In front of the scissors, the kit includes pulling drive rollers (traibapparatus).

2. Installations for accelerated cooling of rolled products. Located in the flow of the mill behind the flying shears. Designed for thermomechanical processing (hardening) of rolled products from rolling heating.

3. Refrigerator Stan 320. Type - rack and pinion. Length - 48 m, width - 7.6 m. Purpose - receiving hot rolled products in bars, cooling them to a temperature of 180-400 o C and further transferring bars 10-48 m long to cold cutting shears with a force of 500 tf.

Cooled rolled products? 10-40 mm, hexagons - 10-38 mm, strip t=4-12, H=25-60, angles No. 2h5, shaped rolled products with a width of no more than 60 mm. Roll length no more than 48 m. Length of the refrigerator (rack system) - 49.5 m. Width of the refrigerator (along the axes of the roller conveyors) - 7.66 m. Speed of the supply roller conveyor - 3-7.2 m/sec, time for raising and lowering the valves - 3.6 sec.

The stroke of the moving slats is 120 and 240 mm.

4. Cold cutting scissors. Purpose: cutting rolls into finished lengths after refrigeration. Cutting force - 500 tf. The length of the cutting edge of the knife is 700 mm. The moving knife is the top one. Knife stroke 155 mm. The tensile strength of the material being cut is y = 100 kg (mm 2), relative elongation of the material d = 6%. The temperature of the material being cut (calculated) is 100 o C, the number of knife strokes is 18 per minute. Number of cuts - 10 pcs./min. The power of the main drive of the scissors is 75 kW, the speed is 575 rpm.

2.2.4 Adjustage

The adjusting equipment of the Section Rolling Shop is located partly in a separate production building, partly in the tail part of the spans of mills 320, 450 (useful area - 5200 m2).

Variety straightening machines

1. Sorting machine 8x800 (2 pcs.).

2. Grade straightening machine PRK-5 (made in Poland).

3. Straightening machine for straightening corners.

4. Sorting machine 11x200.

5. Sorting machine 7x600.

Machines for abrasive stripping of rolled products

Type - hanging, swinging, quantity - 5 pcs. Abrasive wheels - flat, straight profile, grain size - 80-125, wheel sizes 300x40x76 mm, permissible peripheral speed - 50 m/s. Purpose: selective manual cleaning of surface defects on round, hexagonal and square rolled rods.

Drill steel core drawing machines

Quantity - 2 pcs. The dimensions of drilling hollow steel rods are circle 26-37 mm, hexagon - 22.25 mm. Core steel grades - EI-94. The cross-sectional dimensions of the cores in finished products are 6.5-12.5 mm.

3. Description of the technological process in rolling shopsAwater

3.1 Large section workshop

The large-section shop, with the main metallurgical unit - the large-section mill 850, is the head of the rolling process: it receives ingots from the open-hearth shop (and periodically from the outside) and processes (squeezes) them into billets of square or round cross-section and into finished round or square rolled large sections assortment.

The transfer of ingots from the open-hearth shop to the CSC is carried out after the assignment of melting by the quality control department of the open-hearth shop. The assignment of melting according to chemical analysis is carried out no later than the end of the holding time of the ingots in the molds.

The ingots are transferred by float at the highest possible temperature.

Ingots are transferred to the CSC at a temperature of not lower than 700 o C and, as an exception, not lower than 500 o C. Ingots with a temperature of 800 o C are considered hot, with a temperature from 500 o C to 799 o C - warm, with a temperature of less than 500 o C C - cold.

Ingots transferred to the CSC are marked in the open-hearth shop. Special plates attached to the carts indicate the heat number, the number of ingots and the start of removing ingots from the molds. At the CSC, the ingots are received by the quality control inspector (the correct marking of the ingots and the information on the plates, heat number, steel grade, number of ingots, arrival time, ingot landing temperature, etc. are checked) and recorded in a special journal. The surface temperature of the ingots before being placed in heating wells is determined depending on the time they are kept in the molds and transferred to heating (according to special tables).

The procedure for placing ingots in preheating heating groups and performing heating modes for ingots is provided in accordance with the approved technical documentation.

The final heating of the ingots to the rolling start temperature (1100-1230 o C) is carried out in group I of wells.

After final heating, the ingot is transferred for rolling at mill 850 at the command of the operator of the main control station according to the ASG. Data on the rolled profile is reported to the section for cutting rolled products and to the operators of the main control station (stand 900), to the operators of rolling tables and to saws No. 1 and No. 3

Compression modes, high-speed and temperature conditions rolling is carried out in accordance with the approved technology and roll calibrations.

On the 850 mill, several melts can be rolled into different profile sizes simultaneously without rebuilding the mill.

In stand 900, the ingots are given their profitable part. From stand 900, rolls for circles of 140-220 mm and squares of 130-210 mm are transferred to cutting off parts of the defective ends at PUD No. 3, and then to roughing and finishing stands 850. Rolls for circles over 220 mm are transferred to the roughing stand without preliminary cutting to PUD No. 3.

Turning of rolls and movement from caliber to caliber in stand 900 is carried out using a hook tilter (on the front side of the stand) and manipulators; in roughing and finishing stands - with rope tilters and rolling tables.

Cutting of rolled products into the required lengths of finished products and technological trimming is carried out at PUD No. 1 and PUD No. 2.

Cutting is done using dimensional rulers and stops installed at hot cutting saws. Maximum deviations in length when cutting rolls into blanks of measured and multiple lengths, the cutting angle must comply with the requirements of GOST 2590-88, GOST 2591-88.

After cutting the rolled product, each commercial workpiece is hot-stamped on the end, indicating the number of the melt and siphon, steel grade, plant trademark and team sign.

After rolling, the metal is cooled depending on the grade, profile and purpose of the steel:

b in stacks or brackets in calm air in the workshop;

b in thermoses with the lids closed.

Part of the rolled stock undergoing heat treatment (annealing) in four chamber-type thermal furnaces with retractable hearths.

Annealing of some grades of steel is carried out only at the request of the customer.

The KSC produces finished (commodity) rolled products and semi-finished products for the section rolling shop.

In addition to metal annealing, adjustage involves:

1. Cleaning with abrasive wheels on Sh7-05 machines

Defects identified by the quality control department are cleaned up in accordance with the technical requirements for metal. The depth of the defects is determined by “testing” with an abrasive wheel. Workpieces with defects whose depth exceeds the permissible limit are rejected.

Workpieces with increased curvature are preliminarily straightened on the correct press.

2. Turning of round bars.

Round bars with a diameter of 140-280 mm are subjected to turning. Before turning, the metal is straightened on a press.

Turning is carried out on special centerless lathes with abundant and continuous cooling of the cutters by emulsion.

3. Fire cleaning of workpieces.

The blanks are laid in one row on a rack, they are inspected, defects are noted with chalk, and they are smelted using manual oxy-fuel cutters. The stripping should be flat, its depth should not exceed 4% of the diameter of the workpiece.

4. Processing of commercial square products.

Stripping is carried out selectively using hand-held pneumatic tools. Inadmissible surface defects discovered during inspection, as well as burrs, are subject to cutting. In this case, the width of the cutting must be at least 5 times the depth.

The commercial rolled products accepted by the Quality Control Department are loaded into Ministry of Railways cars or sent to the finished rolled products warehouse.

Large-section rolled products with square sections of 130-170 mm are converted billets for special steel mills.

Depending on the purpose, processed billets are divided into three processing (quality) groups.

group P1 -	blanks of carbon steel, alloy steels intended for the production of rolled products, subjected to continuous stripping in the Calibration Shop; shipped to SPC with in-flow control.
group P2 -	blank for rolled material that is not subjected to cleaning in the Calibration Shop; blank 140 mm square of ShKh15 steel for rolling using drawing; blanks, pre-products for special-purpose workshops for hot-rolled steel according to orders from MAP and export with continuous abrasive or fire chargeAndsteadfast.
group P3 -	blanks for all other purposes with removal from the surface visible to the naked eyeeeffects.

Processing of finished workpieces includes:

b Abrasive cleaning on overhead sanding machines (P3);

b Abrasive cleaning on roughing and grinding machines (P2, P3);

b Fire cleaning (P2, P3).

The stripping depth should not exceed 170 mm for sq. - 20 mm, sq. 140 mm - 15 mm. If the depth of the defect is higher than permissible, the workpiece or part of it is rejected. The stripping width must be at least five times the depth.

The finished product is transferred to the special processing center after receiving positive macrocontrol results.

3.2 Section rolling shop

Workpieces arriving from the CSC are weighed before being placed in methodical furnaces. The workpieces are placed in the furnace in whole melts, without breaking; they are checked to prevent mixing of the chemical composition and the correctness of the markings.

Melting of billets in a furnace is separated from each other fire bricks, which are placed on the first billet of the new melt.

Heating of billets of different steel grades is carried out differentiated among several groups of grades, depending on their heating properties (susceptibility to overheating, cracks) and rolling (ductility, resistance to deformation).

Special heating modes have been established for each group and cross-sectional sizes of workpieces by technological documentation, which indicates the parameters for fuel consumption, air, heating rate and temperature in furnace zones, and indicates the temperatures for the delivery of workpieces and the start of rolling (most often 1080-1180 o C)

Positive pressure is maintained in the welding and simmering zones of the furnace. It is normal for a slight amount of flame to escape from the inspection windows. Air leaks into the oven are not allowed. Fuel consumption in the furnace zones should determine optimal heating of the workpieces. The temperature difference between the lower and upper edges of the workpiece should not exceed 50 o C.

Billets are released for rental by float; in order to prevent mixing during delivery, the quality control department checks the markings of the last two and first two billets of each heat. Workpieces with unclear markings or without them are rejected.

Rolling unheated, over-burnt and unevenly heated workpieces is prohibited.

In the Section Rolling Shop, the profile dimensions given in Table 9 are rolled.

Table 9

Rolling modes on the mills are designed taking into account the characteristics of the size and shape of profiles and steel grades in accordance with technical parameters mill equipment and are installed with approved drawings and roll calibration diagrams for each profile size, tables and instructions for reduction modes, rolling speeds and temperatures.

Schematic diagrams of the rolling process on mills 450 and 320 are shown in Figures 6 and 7.

Figure 6. - Scheme of the technical process at mill 450

	workpiece 170-180, 150-154, L=1.3-3.0 m, heating to 1080-1200 o C
	Methodical heating furnaces No. 1; No. 2
		broadcast	blanks for crimping stand roller tables
periodic temperature control, cage settings	Crimping cage trio 680	t start of rolling = 1060-1180 o C
manual tilting with partial mechanization using PKS	in 1-3 rhombic	rolling speed V = 2.3-3.0 m/sec, number of passes 5-7
		t = 1000-1130 o C	transfer by roller conveyors to the 1st stand of the finishing line 450
	Turning bush	edging of the roll section

	1 stand 450 “trio”	rolling in 1-5 passes according to the following patterns: “square - rhombus - square”, “oval - diamond oval”, “rhombus - rhombus” for
transfer of rolled material to stand 2 by roller conveyors, PKS and slappers			reducing sections to sq. 56-80 mm
edging at 90 o, 45 o, 0 o	2-3 stands 450 “trio”	rolling in 1-5 passes in preparatory and pre-finishing gauges

	4 stand "duo" 450 (finishing)	clear pass for ready profile

V roll release = 2.0-3.5 m/sec, t = 850-1000 o C,			release of rolled profile onto a roller conveyor arrival of rolls on the supply roller table of hot cutting saws
	Hot cutting saws	cutting off the end defective parts, dividing the rolled product into rods L=3-6 m, of the ordered length
end trim
for recycling	Containers for trimmings		Outgoing roller table saws, transferring bars to refrigerators
				t = 700-900 o C
		Schlepper chain refrigerators (2 pcs.)	cooling of bars; partially - manual marking (stamping) of rods using the impact method
			t = 100-500 o C
	Pockets for finished products
			packaging, hooking with slings (package weight up to 6 tons)
	Electric bridge crane,
			transportation for adjustment

Figure 7. - Scheme of the technical process at mill 320

	from KSC or from the workpiece side 130-140, L=1.1-3.0 m, cross-sectional area 17000-19000 mm 2, heating up to 1080-1200 o C
	Methodical heating furnace No. 3, three-zone

		transfer to and schlepper,	roller table blanking mill edging is more heated side up
	Crimping cage trio 550	t start of rolling = 1080-1180 o C
	Rolling in boxes (rectangular) calibers 4 passes with intermediate edges according to the “2-2” pattern	rolling speed V = 2.8-3.5 m/sec, for 100: 7 passes for 130h140: 9-11
periodic temperature control, roll settings (size, shape, roll sections), adjustments	Rolling in rhombus-square gauges 5-7 passes according to the scheme edging “1-1-1...”	manual tilting, lifting the roll into the upper horizon of the trio 550 stand using a PKS on the front side of the stand, t at the entrance = 1020-1150 o C

	Drum shears volatile Q=15ts	cutting front and rear defective ends on the fly,
transfer of peal roller conveyors to the line stands 320x750 No. I-VI			L trim = 50-200 mm, rhombic cut t = 40-50 mm, B = 65-80 mm pl. sections 1570-2100 mm 2
	Turner - tribapparatus	edging of the roll section on edge 90 o task in rolls I(II) stand

	Line of working stands No. I-VI (320x750)	transmission of the roll using bypass
checking the filling of gauges, shape and dimensions of sections, adjusting rolls, fittings, bypass devices	Rolling in 3-7 passes from crimp 550 to smaller cross-sectional sizes of square or ribbed shape	devices (automatically), tilting - automatically using turning outlet fittings
	Caliber systems: “square-oval”, “rib oval-oval”, “square-strip”, etc.	t start rolling = 1000-950 o C t end of rolling = 950-900 o C rolling speed V=3.5-4.5 m/sec

transmission and edging automatically using	Cages No.VII, No.VIII (330x600)	section 140х1250 mm 2 t start rolling = 950-900 o C
bypass devices and fittings	Pre-finishing and finishing passes in “oval-circle” or “hexagon-hexagon” or other gauges.	t end of rolling = 820-920 o C rolling speed V=4.0-6.0 m/sec
periodic temperature control, adjustment of rolls and fittings			release of rolled products from the finishing stand for cutting and cooling of finished products
			rolling out the finished profile (see Table 9), V at the exit from the mill = 4.0-6.5 m/sec, t = 800-900 o C, rolling length 50-260 m
	Flying shears, Q=20ts	hot cutting front, rear ends cutting
receipt of rolled material installation in stream			for lengths of rack-mounted refrigerator 25-48 m, transfer of rolls to rack-mounted refrigerator, discharge by valves
Accelerated cooling unit (water)		rack refrigerator, L=50 m, B = 7.6 m	rods onto slats, rolling braking, transverse transmission
					bars by walking racks of the refrigerator
thermomechanically hardened metal		Feeding roller table cold cutting shears	with edging of the section and cooling to 100-300 o C, alignment of the ends
water pressure 16 atm, surface cooling to 300-400 o C, temperature equalization across the cross section				rods, transfer of rods from refrigerator slats, grouping of a package of rods.
Control of the dullness of knives, the shape of the cut, the curvature of the ends, changing knives	Cold cutting press Q=500 tf, blade length 700 mm	Aligning and setting the length of the cut (cutting) of rods using a stop, distributing the rods according to
supply of bars of the ordered length to transport. roller table			streams of knives, cutting a package of rods from 9-20 pcs. peals
control of cutting length, defects	Bar conveyor
			pockets of finished products
	Electric bridge crane,	hooking bundles of rods, transportation, shipment to railway platforms of consumer goods
			body or for finishing and control

Before changing and rolling a new profile size, the mill foreman is obliged to inspect the condition of the rolls and rolling reinforcement and immediately eliminate any deficiencies noted. During the period of adjusting the mills to a different profile or size, it is necessary to reduce the number of revolutions of the motors of the finishing lines of the mills 320 and 450 to improve the capture of the rolled material by the rolls.

When rolling any profile, the senior rolling operator is obliged to monitor the correct operation of the rolls, rolling fittings and the setting of the mill. When switching from one profile to another, rolling begins with test blanks (from scraps and under-rolls).

If whiskers, displacements, scratches, dents and other visible defects are detected on the surface of the rolled product, the senior rolling operator must take measures to eliminate the causes leading to rolled product defects.

The undercuts and workpieces formed during the rolling process in the crimping stand must be marked with a steel grade for reheating. Under-products from mill 450 are transferred by a transfer cart to the production preparation area to check for uniformity and the presence of a mark, with subsequent attachment to the main batch of metal.

Cutting of rolled products is carried out in a hot state from the mill 450 with sled saws. Metal cutting on the hot cutting saws of the 450 mill is carried out in packages assembled depending on the size of the rolled steel.

The rods cut on hot cutting saws are branded. Waste obtained from cutting metal, as well as defects obtained during the rolling process, is stockpiled and stored in the workshop in accordance with what is set out in Section 7 of this report.

Products received for adjustage are subjected, if necessary, to editing, in order to eliminate surface defects, to inspection, sorting and cleaning.

Metal with increased curvature is straightened on console leveling machines. Editing is carried out both cold and hot.

Identification and removal of surface defects:

b Lightening with a “snake” is carried out on round rolled products (diameter 32 mm or more, length no more than 4000 mm). The snake pitch should not exceed 300 mm.

b The application of “loops” is carried out on round bars (length more than 4000 mm, same diameter) and on all hexagonal bars at two points at a distance of 100-200 mm from the end of the bar.

Brightening of rolled products and removal of surface defects and burrs obtained during cutting of rolled products is carried out on overhead sanding machines.

It is prohibited to process metal on racks from which metal from other melts has not been removed.

Before putting the bars into straightening machine, the straightener inspects them on the receiving table. Detected gross defects on the surface of the rods (frayed ends, cracks, flaws) are sanded. Individual rods must be turned 180°C to orient the defective ends in one direction. In this case, a cold stamp is applied to the opposite end of the rods indicating the heat number.

Finished products for export orders, as well as hot-rolled metal with the letter “L”, are subjected to sparking after processing. In accordance with the order requirement, the treated metal can be painted.

Inspection of rods after processing is carried out by quality control inspectors. The products accepted by the quality control department are collected in packages with a mass that ensures safety conditions, and tightly tied with wire in 2-3 places depending on the length of the rods. The products bundled in bags are hung with two marking and weight tags, which are firmly attached to different strappings on the side convenient for viewing.

The metal is delivered to the finished product warehouse only after processing is completed and presented to the quality control inspector.

Export metal prepared for shipment is stored in a specially designated place to prevent bending of the metal and damage to the closure. It is prohibited to store metal under open air. The metal is packaged so that the cross-section of the bundle approaches a circle, hexagon or rectangle. One end of the bag must be aligned.

4. Characteristics of raw materials, fuel, basic materials

Raw materials are minerals, others Natural resources, as well as materials produced from them that are subject to further processing A.B. Borisov. Big economic dictionary. - Moscow: Book World, 2003. .

Blast furnace shop of JSC Metallurgical Plant named after. A.K. Serova" smelts cast iron, which is supplied in cast iron ladles to the open-hearth shop, where steel is produced. Steel is poured using a siphon method into molds, thereby obtaining ingots. Ingots are subject to processing in the CSC, therefore they are raw materials for the CSC.

In the open-hearth workshop, ingots are cast weighing 5.6 tons. Control weighing of ingots is carried out once every ten days in the presence of representatives of the CSC, the open-hearth shop and the technical department.

During normal casting, the height of the solidified profitable part should be:

b for ingots weighing 5.6 tons when lining the profitable extension with fireclay bricks - 240-350 mm;

b for ingots weighing 5.6 tons when lining the profit extension with liners - 200-340 mm.

When rolling ingots with incomplete profit (the last to be cast or lagging behind the siphon), the head cut is increased according to Table 10.

Table 10

The height of the profit filling in these cases is determined by a four-stage template with a step height of 165, 225, 285, 335 mm (when using extensions lined with fireclay bricks) and with a step height of 160, 220, 280, 330 mm (when using extensions lined with liners). Ingots with incomplete profit are separated by separate siphons. An entry is made in the melt passport and the chemical analysis book of the SSC about ingots with incomplete profit.