In the first five-year plan, in addition to 20 metallurgical plants left over from tsarist times and subject to modernization, for the production of the most important product of industrialization - steel - it was planned to build three more metallurgical giants from scratch - in Magnitogorsk, Kuznetsk and Zaporozhye

Hard thin steel sheet "Zaporizhstal"

In the first five-year plan, in addition to 20 metallurgical plants left from tsarist times and subject to modernization, for the production of the most important product of industrialization - steel - it was planned to build three more metallurgical giants from scratch - in Magnitogorsk, Kuznetsk and Zaporozhye.

To coordinate the construction of new and upgrade already existing factories was established in 1926 Gipromez- State Institute for the Design of Metallurgical Plants. From 1927 to 1932 between Gipromez and an American company Freyn Engineering Company of Chicago a technical assistance agreement. A group of American engineers and metallurgists, according to the agreement, was obliged to train Soviet engineers, managers, designers and operators of metallurgical equipment in the latest standards of American metallurgy.

In addition to the routine training of specialists, according to company president Henry Frain, the main task of the American experts was the master planning of the distribution of capacities and the rational placement of the entire future metallurgical industry of the Soviet Union.

According to the memoirs of one of the American engineers, V.S. Orra:

« At first, when we (Americans) appeared in Gipromez, we only asked questions. All drawings, reports were made by Russians, all decisions were made by Russians. Six months later we were creating blueprints, nine months later we were the chief designers of metallurgical plants, and at the end of the first year of our work, some of us became heads of departments. In the last year of our work, one of us became assistant to the chief engineer of the entire office. We brought efficiency to work, removed unnecessary operations and made Gipromez itself most effective organization of the entire Union."

One of the three giants of the first five-year plan, the Kuznetsk Iron and Steel Works was built under the direct supervision of a group of engineers from Freyn Engineering Company. The Freyn contract with Novostal for the construction of KMK with a capacity of 1 million tons per year was signed on June 4, 1930. Under the contract, more than 50 American specialists provided design, construction supervision, installation and commissioning of KMK.

Perhaps the greatest value for the USSR among all imported technologies was the receipt of the latest American technology for the continuous (roll) production of thin steel sheets.

The problem of obtaining wide sheet metal strips in rolls was solved relatively recently - in 1924. Previously, separate attempts were recorded, but due to the imperfection of the technique, they ended in failure. Several factors interfered.

Firstly, the general steam drive, which was used everywhere in metallurgy, made it difficult to accurately control the speed of rotation of individual mill stands.

Secondly, only rolling bearings made it possible to switch to high rolling speeds and high loads required in the continuous production of steel sheet.

There was also the problem of bending the long rolls of the two-roll stand, which caused the sheet to be of uneven thickness.

However, with the release of technology at a certain stage, it became possible to produce high-quality thin steel sheets.

A three-roll stand appeared, the design of which resisted the bending of the rolls much better. The rolls themselves had surface curvature (concave and convex). Each cage was driven by its own electric motor with an adjustable number of revolutions.

For the first time rolling of this type was mastered by the company " American Rolling Mill Co. in Ashland in 1924. The mill could produce a continuous sheet with a thickness of 0.9 and a width of 1040 millimeters.

In the mills of the following design, which have been put into operation throughout America since 1926, four-roll stands and roller bearings have already been used. high speeds allowed not to install additional furnaces between the equipment.

The production of a thin steel sheet on an industrial scale made it possible to make a huge technological leap in the production of automobiles, aircraft, military equipment due to the simplification and simultaneous strengthening of the design of the designed part, made from one single sheet.

As of 1937, there were 21 continuous rolling mills in America in operation, while in Europe such mills were only being built - one in Germany by the company Vereinigte Stahlwerke, one - in England by the company Richard Thomas.

Soviet Union during the construction of Zaporizhstal in February 1935, he concluded with an American company United Engineering and Foundry Co. contract for the development and supply of hot and cold rolling mills. According to the agreement, 3 million dollars were paid for equipment, 1 million for technical assistance. We agreed that about 20% of the equipment is supplied from the States, the rest is made in the USSR under the control of the Americans. The company guaranteed technical assistance in the start-up and development of production, and also undertook to ensure the specified productivity and proper quality of steel sheets.

An interesting point: according to the agreement, each American specialist had to be provided with a separate apartment with a bathroom for the period of his stay in the USSR.

Simultaneously with this agreement, another was concluded - with the company American Standard Corporation for the supply of equipment for rolling mills for $3 million.

From the official website of NKMZ (Novokramatorsky Mashinostroitelny Zavod):

“In 1934, there were no such complex rolling equipment units in Europe as continuous wide-strip sheet mills. The Soviet government decided to build a continuous mill at the Zaporizhstal plant, and to do this, buy a mill design and some of the most sophisticated equipment in the United States. A commission was organized from representatives of the Zaporizhstal plant, NKMZ, Gipromez, Stalproekt, the Electrosila and KhPKU plant, the Kharkov Design and Design Department of Electric Drives. […] The commission left in December 1934, first for Germany, and from there, a month later, for the USA.

The company, after the completion of the installation, undertook to hand over the equipment to Zaporizhstal on the move, bringing the design capacity of the hot rolling mill to 100 tons per hour or 600 thousand tons per year of a sheet with a thickness of 1.5 to 6 mm. At the time, it was a colossal performance.

Two receivers from United Corporation went to NKMZ, and a group of consultants went to Zaporizhstal for the time of installation.

Technologists and production workers of the USSR brilliantly coped with the manufacture of complex and precise equipment of the mill. NKMZ was assisted by Uralmash, which produced skin-pass mills; SKMZ created adjudication: flying shears, straightening machines, guillotine shears; The Izhora plant supplied various individual machines. Most of the equipment for hot and cold rolling mills was manufactured at NKMZ.

In February 1937, hot rolling mill 1680 was put into operation and showed high quality production by Soviet factories of equipment that was not inferior to that purchased in the United States.

Under the contract, Zaporizhstal and NKMZ had the right to send up to five specialists for practice at the same time for a period of up to six months. This provision of the contract was used. NKMZ engineers M.Z. Saburov, V.N. Yakovlev, A.M. Kolesker gained experience in the workshops of seven factories of the company, Zaporizhstal rolling workers - at a metallurgical plant.

They treated our engineers in America, according to them, with coolness, not seriously. They weren't allowed to take notes or take pictures. It was allowed to watch from afar. Somehow one of the Cossacks, curious, went behind the fence and thereby activated the protective device. The siren wailed. The Soviet delegation in full force was expelled from the workshop.

Trainees - metallurgists complained about the condescending attitude of the Americans. They said: - Oh, why do you need to study, why build? It's troublesome. Such a camp is not a Russian cart, but a complex and delicate mechanism. You still won't get anything out of this venture. Wouldn't it be better to get a ready-made sheet from America?

Future Chief Engineer Zaporizhstal Yudovich recalled such a conversation with an American technologist:

« - Well, - said the American, - you will receive the calibration data. If you were from England or Germany, you would never do this.

- Why? Yudovich was surprised.

- The British or Germans would immediately use it at home. But since you are from Russia, it is safe. If you can't use it anyway, you won't be able to.»

T.V. Jenkins, chief engineer of United Engineering in the USSR, spoke about the problems of installing rolling mills in Zaporozhye :

“One of the most important problems discovered in the course of cooperation with Russian mechanics and workers was their stubborn ignorance or misunderstanding of the requirements for precise fitting of mating surfaces during equipment installation. They refused to follow the tolerances specified in the drawings. This is one of the reasons why, in December 1937, the very quickly installed equipment could not pass the acceptance tests.

In fairness, the opinion of the Soviet side should also be cited. The operator of the expansion stand of the thin-sheet mill, a participant in the launch, A. V. Miloserdov, recalled:

- The roughing and finishing stands were adjusted differently. In finishing - they planted a shaft using a special device, roughing - by caliber. They were suggested by our mechanic I. 3. Shlykov. But the American consultants abandoned the calibers and ... set up the fourth stand using the shaft-to-shaft method until the lower support roll was broken.

From the memoirs of the former deputy chief mechanic of NKMZ S.3.Milochkin:

“...overseas specialists refused to make drawings in the European version. This created additional difficulties for our designers ... Which of the older generation of Kramatorsk machine builders does not remember the drawings with a warning inscription: "Attention, American projection!"

Although the official website of NKMZ in the "history" section says the exact opposite:

After concluding a contract with United Corporation, American designers specified materials, rolling bearings, fasteners and other components according to Soviet standards.

On April 14, 1938, the first strip was rolled at mill 1680. The senior roller operator Pyotr Tarasevich, having rolled the first sheet, immediately steel tape scribbled: " Long live the first Soviet leaf! Curse the import sheet!"They say that the American consultant Mr. Feisner was offended and went to complain about Tarasevich to the party organizer ... (By the way, P.D. Tarasevich retired as a lieutenant general.)

On May 1, the 1680 mill was officially launched. And in 1940, Zaporozhye already produced 1,500 tons of steel sheet per day, or about 600 thousand tons per year.

By the beginning of the second five-year plan, the metallurgical plants of the USSR produced 10 million tons of pig iron, 7 million tons of rolled products, and 9.8 million tons of steel.

These volumes did not satisfy the leaders of the country - metallurgical products, especially special steels for the military industry, needed much more.

By 1937, the output of rolled products was to be 14 million tons, with an increase of 326% by 1932. The country needed 107 rolling mills, and in 1933 only twelve were installed.

The technical level of the rolling shops had to surpass the level of European metallurgy.

The Kuznetsk rail and beam mill was supposed to produce more rails than the old rail mills. It was planned to install a thin-sheet continuous mill at the Zaporozhye plant, which would roll much more thin sheet iron than the entire metallurgy of the USSR in 1934.

Speaking in February 1934 at the XVII Congress of the CPSU (b), Iron Commissar G.K. Ordzhonikidze called mechanical engineering "the key to the reconstruction of the national economy." Offering to use it skillfully and rationally, Ordzhonikidze said that the volume of machine-building output in the second five-year plan would increase by 217%.

At the "congress of winners", which proclaimed Stalin the sole leader of the party and the entire Soviet people, the director of NKMZ I.T. Kirilkin. He already knew that the sheet mill and slab for Zaporizhstal were scheduled for production at Novokramatorsky Zavod.

Soon a commission was formed to purchase the project of the modern mill 1680 and its most complex equipment. The commission included representatives of Stalproekt, GIPROMEZ, Zaporizhstal, Elektrosila, Kharkiv Electric Drive Design Department and NKMZ, the main manufacturer of unique equipment.

From NKMZ, the commission included the head of the rolling equipment bureau V.L. Shvayun, head of the mechanical shop I.T. Katerinich, leading engineer of UKS P.G. Quail. The commission visited 25 US plants producing similar mills. The contract with United Corporation was signed on February 1, 1935, the USSR paid $3.0 million for the mill project. In addition, a finishing group of working stands, a set of flying shears and some other equipment were purchased.

NKMZ, like other large new buildings of the first five-year plans, was swimming in a sea of ​​problems - the shops were not fully equipped with equipment, the workers did not have the level of skill that mechanical engineering required in principle, and precision imported machine tools in particular, planning failed. Among the engineers, only 24% had engineering degrees, more than 40% were practitioners, only 4.4% of workers had a high grade VII, 70% of workers had low qualifications.

And yet, the American millionaire and philosopher Henry Ford admitted: “The Russians win half a century of experience. They are moving towards keeping up with the times in industry.”

In 1936, for the first time in the USSR, NKMZ mastered the largest products: stationary tunneling shields for the construction of the Moscow metro, an overhead crane with a lifting capacity of 220 tons for Zaporizhstal, two gantry cranes with a lifting capacity of 150 tons for lifting shields on the Moscow-Volga canal, a winding machine with a drum Ø6 m for Uralasbest, pyrite furnaces for the production of sulfuric acid, shears with an upper cut with a pressure of 700 tons for the metallurgical plant named after. Dzerzhinsky and other equipment.

This year also includes the first complete delivery of units for the construction of new plants.

A serious problem of NKMZ was the lack of experienced designers. Perhaps that is why the creators of the first Soviet blooming Wilhelm Avgustovich Thiele and Arved Genrikhovich Zille appeared at NKMZ, who headed technical department. V.L. Shvayun, V.F. Sobol, A.M. Rybalchenko, E.A. Bogomolov, I.G. Belyaev, G.L. Vinnik, L.M. Vitushinsky, I.L. Hare. Vasily Kharitonovich Chaika became the lead designer of the slab.

This slab was the first not only in the USSR, but also in Europe, Novokramatorsk designers practically had no documentation for analogues, they had to rely on “pictures” and the experience of engineers who visited the rolling shops of American enterprises, literary sources, and a limited supply of technical documentation.

Initial preparation and design, development technical project and equipment specifications, drawing up a general layout plan, as well as developing some slabing units were engaged in the Central Bureau of Heavy Engineering (Moscow), organized on the personal initiative of G.K. Ordzhonikidze. Already six months later, in the summer of 1934, the documentation for slabbing from Moscow was transferred to NKMZ.

Having no research and experimental base, the reverse four-roll slab was designed in an extremely short time. Many constructive ideas were introduced into his project, which significantly distinguish him from similar rental cars in the USA.

Powerful slab rolls rolled metal ingots weighing from 4 to 15 tons, the productivity was determined at 1.2 million tons per year. The total weight of the slab equipment was 3,780 tons, the length was 115 m, and the power of the main drives was 12,500 horsepower.

It is characteristic that shears with an upper cut with a pressure of up to 2000 tons, on which workpieces up to 200 mm thick and up to 1500 mm wide, were cut, were the first model of electric shears in the world, and the frame weighing 187 tons was the largest casting in Europe at that time. Bold decisions designers laid in the manipulator, pressure device.

In the manufacture of slabing parts, the shift of the steel shop of the master D.V. Antsiferova, steelmakers of electric furnaces V. Afonin, A. Ovcharov, F. Mostovenko, a team of molders E.V. Dawns. The blanks of slab parts were processed mainly in the machine shop No. 1, the Komsomol assembly teams of Vasily Borisenko and Aleksey Markiyanov assembled the unit, assemblers A.A. Fomenko, Ya.I. Fedorenko, S.N. Arkhipov, G.A. Druzyak, V.A. Sinelnikov under the leadership of the head of the section V.I. Dotsenko, who recently returned from a scientific trip to the United States.

Subsequently, the leading engineer of slab 1100 V.Kh. Chaika said: "If the first Soviet blooming was designed by the old-school specialists, then the project of this more complex and powerful mill was already created by our Soviet specialists."

At NKMZ, it was assumed that the plant would have to produce many more rolling mills, so in December 1936, an external assembly shop was organized at the plant for the installation and commissioning of equipment at customer enterprises. Perhaps its first leader was Konstantin Ivanovich Koval - in the past a Leningrad engineer, who was called a brigade commander at the installation of a slab and a mill, in the future - a deputy people's commissar of heavy industry of the USSR.

Following the slabbing, the adaptation of the American documentation for the thin sheet mill to the conditions of Novokramatorsk production began.

G.K. Ordzhonikidze, who closely supervised the manufacture of the first rolling mills in the USSR, emphasized then: “The truth is to transfer the achievements of foreign technology to us.”

The second part of the truth was that the designers not only gained experience in creating units that had not yet been produced in Russia, but also made many improvements to the machine components. They realized that "not the gods burn the pots" - there were many changes in the drawings of United. True, as a result of this, new models, castings, forgings, and parts had to be re-manufactured.

In 1937, the Zaporizhstal hot rolling mill 1680 was manufactured. SKMZ, Uralmash, Izhora Plant took part in its creation. NKMZ as a general supplier accounted for 11,000 tons of unique equipment. The director of the plant E.A. controlled the manufacture of the mill. Satele, appointed to this post in the spring of 1936.

In 1937, a team of 300 installers, assemblers and designers led by K.I. Kovalya mounted and launched the slab. On March 14, 1937, the train with open-hearth steel ingots headed for the new workshop for the first time. At night, a “lightning” was sent to the People’s Commissariat of Heavy Industry of the USSR: “Today at fifteen o’clock slabing was tested. Four seven-ton ingots have been reduced.” On April 1, 1937, the slabing entered service.

On April 14, 1938, the first strip was rolled at mill 1680 of Zaporizhstal. At the metallurgical plant, they later recalled for a long time how the senior rolling worker Pyotr Tarasevich, having rolled the first sheet, immediately wrote in a sweeping manner on a steel tape: “Long live the first Soviet sheet! We curse the import sheet!” The consultant, Mr. Feisner, was offended and went to complain about Tarasevich to the party organizer ...

On May 1, the 1680 mill was officially launched. In September, after reaching the design capacity of 600 thousand tons per year, it was put into operation.

In parallel, according to American documentation, equipment for the cold rolling shop was designed and manufactured. The cold rolling shop of the Zaporizhstal steel plant, equipped with unique equipment, including a three-stand continuous mill 1680, eight thermal furnaces, skin-pass mills, flying shears, produced its first products on April 1, 1939. This work was led by engineers I.G. Belyaev and V.G. Shalnev.

As they recall at Zaporizhstal, for some reason the Americans were late for the launch, and when they arrived and saw the equipment in operation, they were very surprised.

While the designers were mastering the production of rolling equipment, Novokramatorsk metallurgists managed to break the United Corporation monopoly on the supply of cold rolling rolls.

In 1938, NKMZ manufactured equipment for a continuous billet mill 450 of the Makeevka Iron and Steel Works, a large-section mill of the Stalingrad Iron and Steel Works "Red October". The last pre-war two-stand sheet-rolling mill of the Amurstal steel plant (Komsomolsk-on-Amur) was put into operation during the war. It was designed under the guidance of the leading engineer V.V. Brekhov.

In 1937, in terms of industrial production, the USSR ranked second after the United States. The import from abroad of more than 100 types of industrial products was stopped, in general in 1937 specific gravity imports in the country's consumption fell to 1%.

There are two metallurgical plants in Ukraine, where the production of cold-rolled strips is organized: the metallurgical plant "Zaporozhstal" (Zaporozhye) and the metallurgical plant in Mariupol. Zaporizhstal Iron and Steel Works operates a continuous broadband mill (SSHP) 1680, two reversing mills 1680 and 1200 with four-roll stands, one twenty-roll mill 1700, two continuous tin rolling mills with barrel lengths 450 and 650, and a single-stand mill 2800.

 A continuous four-stand SHSHP 1700 operates at the Mariupol Metallurgical Plant.

  Technical specifications SHSHP 1680 and 1700 are presented in table. 4.1.

 Let's take a closer look at the technological process of strip production in the cold rolling shop of the Zaporizhstal Iron and Steel Works (Fig. 4.1). Hot-rolled coils from the shop for hot rolling of thin strips along an underground conveyor 33 are delivered to the warehouse to continuous pickling units (NTA) 1-3, in which strips of adjacent coils are butt-welded into an endless thread. In the process of moving the strip in the NTA, the scale is mechanically cracked and subsequently removed in baths with sulfuric acid (hydrochloric acid) solution. After removing the solution by hot and cold washing,

  Rice. 4.1 - Layout of the equipment of the cold rolling shop No. 1 with a continuous four-stand mill 1680.

 1 - pickling line No. 1; 2 - pickling line No. 2; 3 – pickling line No. 3; 4 – continuous four-stand mill 1680; 5 – reversing mill 1680; 6 – reversing mill 1200; 7 - bell-type single-foot furnaces; 8 - temper mill 1700 No. 1; 9 – temper mill 1700 No. 2; 10 - transverse cutting unit No. 1; 11 - transverse cutting unit No. 2; 12 - transverse cutting unit No. 3; 13 - transverse cutting unit No. 4; 14 - quarto cage; 15 - hardening line No. 1; 16 – hardening line N2; 17 - 20 - roller mill; 18 - mechanical workshop; 19 - H / w. Mesterska 20-roll mill; 20 – strip grinding unit; 21 - H / w. plot; 22 - cutting unit; 23 - pantry; 24 - washing unit; 25 - electric furnaces; 26 - 4-stand mill 450 OBZH; 27 - 4-stand mill 650 OBZH; 28 - OBZh dissolution unit; 29 - duo mill No. 1,2,3,4 LIFE SAFETY FUNDAMENTALS; 30 - units of hot tinning OBZH; 31 - slitting unit; 32 - workshop of power engineers; 33 - underground conveyor; 34 - mechanical service spare parts warehouse.

  Table 4.1. Characteristics of ShSHP 1680 and 1700

followed by drying the surface of the strip and oiling it with an emulsion of high-performance synthetic lubricant.

The hot-rolled strip prepared for rolling is cut into lengths to form enlarged (double) coils with a mass of ~G=11-15 tons.

 If hot-rolled strips are rolled from double-length slabs, the coils are not coarsened after pickling.

 C NTA pickled coils are sent for rolling to a continuous mill 1680, to reverse mills 1680 and 1200, or to a reversible twenty-roll reversing mill 1700 of the Sendzimir type. Mills 1680 are designed for rolling strips from low-carbon (08KP, 08Yu, 10PS, 15PS, 20PS, 20, 25, St.3SP, etc.) and low-alloyed (09G2, 10KhNDP, 10G2, 16G2, 08GSYuF, etc.) with a thickness of 0.5 -2.0 mm. On mill 1200, low-carbon steel with a thickness of 0.5-0.6 mm is rolled, and mill 1700 is designed for rolling strips 0.8-1.6 mm thick from alloyed and stainless steels (12X18H10T, 10X14AG15, 08X18T1, 12X21H5T, 09X16H4B, etc.)

  As a result of the total deformation of the strips within the metal is hardened and practically loses its plastic properties. Therefore, cold-rolled strip coils are transferred to the thermal department, where recrystallization annealing is performed in bell-type furnaces 7. Coil annealing is performed in a protective atmosphere that prevents oxidation of the strip surface. duration and temperature regime annealing are due to the thickness and chemical composition strip material. In order to prevent sticking (welding) of coil turns during annealing, roughness is applied to the surface of the strips in the finishing stand of a continuous mill with notched rolls. After annealing at temperatures t = 670 - 710°C, the flow stress of steel grades 08kp (08 ps) decreases from s t = 700 - 750 N / mm 2 to s t = 220 - 240 N / mm 2, and the relative elongation increases with d = 1.5% to d = 35 - 40%.

The production capacities of Zaporizhstal are:

· Sinter shop (6 sintering machines);

· Blast furnace shop (4 blast furnaces);

· Workshop for the preparation of trains;

· Foundry;

· Crimping shop;

· Shop of hot rolling of a thin sheet;

· Cold rolling shop No. 1;

· Cold rolling shop No. 3.

Picture 1 Production structure of PJSC "Zaporizhstal"

The main iron ore sinter is produced in the sinter shop of the plant. Almost all sinter production processes are automated.

Blast furnace production annually smelts about 3.5 million tons of pig iron/year. A distinctive feature of cast iron produced by MK Zaporizhstal is its low content of sulfur and phosphorus.

The production of the open-hearth shop is about 4.0 million tons of steel/year. Open-hearth furnaces use natural gas. The steel is purged with oxygen and argon. The smelted steel is poured into ingots weighing up to 18.6 tons, which are used for the production of flat products.

Foundry production is the basis for obtaining cast billets of spare parts and replaceable metallurgical equipment for the workshops of the plant and third-party consumers, which includes a specialized department for the production of molds. The design capacity of the mold department is 360,000 tons/year.

The thin sheet hot rolling shop produces hot rolled products in sheets and coils with a thickness of 2.0 to 8.0 mm. The thin sheet hot rolling shop is equipped with units to ensure the supply of rolled products in sheets and coils. Continuous sheet mill “1680” with a maximum production capacity of 3.7 million tons per year is designed for the production of hot-rolled strips with a thickness of 2.0-8.0 mm, a width of 860-1500 mm, a coil weight of up to 16 tons. 500 standard sizes of cold-formed profiles made of carbon and low-alloy steel grades with a thickness from 1.0 to 8.0 mm and with a profile development width of up to 1440 mm.

Cold rolling shop No. 1 produces cold-rolled flat steel with a thickness of 0.5 to 2.0 mm, a width of 850 to 1500 mm in sheets up to 4000 mm long and in coils weighing up to 16 tons, as well as cold-rolled strip with a thickness of 0.2 to 2.0 mm.

Cold-rolled cold-rolled rolled products from carbon and low-alloy steel. The workshop is equipped with facilities for skin pass, cross-cutting and slitting, which ensure the supply of cold-rolled steel with a thickness of 0.2 to 2.0 mm, a width of 10 to 1500 mm and a sheet length of up to 3950 mm, as well as coils weighing up to 15 tons.

Cold rolling shop No. 3 at mill 2800 produces cold-rolled sheet with a thickness of 1.5 to 5.0 mm, a width of 1000-2300 mm and a length of up to 3500 mm from carbon grades become. The workshop includes a specialized department for the production of ground and polished sheets and rolls. Maximum productive capacity for hot-rolled steel - up to 3.7 million tons, for cold-rolled steel - 1.1 million tons, for cold-formed sections - up to 500 thousand tons.

The main activity of the Group is the production of iron, steel and consumer goods at the plant, as well as the sale of these products in Ukraine and abroad. The main consumers of the Group's products in Ukraine are enterprises of the automotive, machine-building industries, agricultural and transport engineering, as well as the pipe industry.

The high quality of the company's products is confirmed by the demand for it in the domestic and foreign markets. It is in demand in more than 50 countries of the world (Turkey, Italy, Poland, Russia, Syria, Israel, Bulgaria, Ethiopia, Nigeria and others), and the Ukrainian market remains the strategic direction of the plant's sales policy.

The plant occupies a stable position in the market, year after year moving up in the list of the largest steel producers. The main efforts of Zaporizhstal specialists are aimed at developing new markets and types of products, strengthening the positive image of the enterprise, expanding the geography of deliveries. The basis of success is strict adherence and continuous improvement technological processes, high quality of products, clear fulfillment of contractual obligations, focus on market needs and skillful implementation market mechanisms management.

SECTION 4. PRODUCTION OF HOT ROLLED STRIPS AND SHEETS

ON BROADBAND HOT ROLLING MILLS

Wide-strip hot rolling mills (SHSHP) include multi-stand mills with the placement of stands in roughing and finishing groups. In the roughing group, both non-reversible and reversible stands are used, located discontinuously or continuously, and in the finishing group, the stands are always located continuously. All products at ShSGP are wound on winders.

Assortment

On ShSGP rolled sheet and strip products with a thickness of 0.8 to 27 mm and a width of up to 2350 mm. The main assortment of mills of this type is strips with a thickness of 1.2-16 mm from ordinary and high-quality carbon, low-alloy, stainless and electrical steel grades.

Consumers

General mechanical engineering, shipbuilding, agricultural engineering, production of welded pipes, rolling stock for CKU.

Types of SHGP

Continuous.

Semi-continuous.

Combined.

3/4-continuous.

Location of the main technological equipment these mills are shown in Fig.29.

The classic continuous SHSHP is characterized by a discontinuous arrangement of the stands of the roughing group. Moreover, the distance between the stands increases from the first to the last stand in order to ensure the condition of finding the roll in only one stand. This is due to the fact that asynchronous AC motors are used as a drive in the stands of the roughing group without the ability to control the rolling speed. In front of the roughing stands with horizontal rolls, vertical rolls are installed driven by DC motors and with the possibility of matching the rolling speed in them with the rolling speed in the stand with horizontal rolls. The purpose of using stands with vertical rolls is to remove the broadening formed in horizontal rolls and work out the metal of the edges to prevent their rupture.

The intermediate roller table must ensure complete placement of the roll coming out of the roughing group of stands, that is, “untie” the roughing and finishing groups of stands, since the speed of the roll exit from the last stand of the roughing group is 2-5 m/s, and the entrance to the first stand of the finishing group - 0.8-1.2 m / s.

This is followed by flying shears, in which the front and rear ends of the roll are cut (if necessary) and an emergency cut is made when “drilling” the strip in the finishing group of stands or on the discharge roller table and winders.

The finishing group of stands is always continuous with a distance between stands of 5.8-6 m. The number of stands is 6-7.

The discharge roller table is equipped with a showering installation.

For winding strips, two groups of winders are usually provided.

The distance between the main units is shown in Fig.29.

Semi-continuous mills have been and are being used for smaller production volumes. One draft reversible stand is provided as a draft stand. On modern mills, it is universal.

The rest of the equipment is similar to the continuous SHSHP, but 6 stands are used in the finishing group, and the winder group is usually one.

Combined mills are characterized by the fact that a two-stand TLS is used as a roughing group, then there is a schlepper for transferring thick sheets to a finishing section, also similar to the TLS.

After the intermediate roller table, a six-stand continuous group of stands is installed.

It is characteristic that the barrel of rolls of roughing stands is larger than that of finishing ones.

The discharge roller table and winders are located as on a semi-continuous SHGP.

Main dignity combined mills - a wide range of products (usually 2-50 mm thick, 1000-2500 mm wide).

Basic flaw mills of this type - insufficient loading of equipment, both when rolling thick and thin sheets.

In this regard, the combined mills were no longer built more than 30 years ago, but the built ones are mostly working.

There are two such mills in Russia.

3/4-continuous mills are characterized by the presence of a vertical descaler, a reversible universal stand and a two- or three-stand continuous subgroup. All other equipment is the same as on a continuous SHGP.

The mill scale along the ShSGP production line is cracked in horizontal and vertical scale breakers, and also knocked down in high-pressure hydraulic knockers (primary), secondary - before the finishing group of stands in horizontal scale breakers or hydraulic knockers (see Section 7).

Generations GSGP

It is generally accepted to divide the SHGP into generations. Table 14 presents their characteristics.

The first SHGP began to work in the USA. The characteristic features of the GSGP of the first and second generations were the use

– duo stands as a scale breaker, located immediately after the heating furnaces;

– hydraulic scale removal before rolling in roughing stands;

– discontinuous arrangement of the stands of the roughing group (peel was not rolled simultaneously in two stands);

-universal quarto stands in the roughing group;

- an intermediate roller table with a length greater than the length of the rough roll outgoing from the last stand;

– flying scissors for trimming the ends of the rolls and performing an emergency cut;

–finish scale breaker duo;

– continuous arrangement of quarto stands in the finishing group;

– a sufficiently long roller table after the finishing group of stands;

– winder for winding the strip into a roll.

The first stage of development was the longest. The classic SHGMP of the first generation is the still operating mill 1680 of JSC Zaporizhstal, put into operation in 1936. It provided for the rolling of strips 2-6 mm thick and up to 1500 mm wide. A feature of the mill 1680 was the presence of an expansion stand and a press in the roughing group. The broadening stand was used for rolling strips when their width was greater than the width of the slab, and the press was used to align the "littered" edges of the rolled product and ensure it had the same width along the length. Compression in the press was 50-150 mm.

Table 1

Characteristics of SHSGP

After reconstruction in 1956-1958. at the 1680 mill, rolling with broadening of slabs was no longer used. And the press was stopped operating even earlier due to the low speed of the compression operation and a number of design flaws. The last SHGP in the world where an expansion stand was used was the SHGP 2500 of the Magnitogorsk Metallurgical Plant OJSC (also the SHGP of the first generation), which began operation in 1960. This need was caused by rolling strips 2350 mm wide. The 2500 mill is also characterized by the fact that it has the longest roll barrel length in the world (for SHGP). Currently, the 2500 mill uses continuously cast slabs up to 2350 mm wide and the need for an expansion stand is no longer needed.

Since the hydro-scale scales had low water pressure at that time, the furnace scale had to be cracked first. For this purpose, the duo rough scale breaker was designed. It produced very small compression (2-5 mm). With the increase in water pressure in the hydrodescaling, this stand began to be used as a roughing stand with reductions up to 20-30%.

The growing demand for sheet products has led to the creation of the second generation SHGP. The assortment of strips has been expanded both in thickness and width (the length of the roll barrel has been increased), the mass of slabs has significantly increased (up to 45 tons) and the rolling speed has increased up to 21 m/s.

The increase in the mass of slabs caused the lengthening of the rolled strips and, in connection with this, worsened the temperature conditions for their rolling, mainly due to the drop in the temperature of the strip when it entered the first stand of the finishing group at a relatively low rolling speed. And since the limitation of the rolling speed was (and still is) the speed of capturing the front end of the strip by the coiler (no more than 10-12 m/s), then the acceleration of the finishing group of stands was used for the first time at the second-generation SHSHP. It was started immediately after the strip was captured by the winder. It can be considered that this is the main qualitative difference between the second generation SHGP and the first one.

The annual production capacity of the second generation SHGP approached 4 million tons. The number of stands has been increased both in the roughing and finishing groups.

Characteristic of this generation of SHSHP is a further increase in the number of stands, and, consequently, the production line of mills, as well as the expansion of the range of rolled strips in size, including width, which required an increase in the length of the roll barrel up to 2400 mm (see Table 14). ). With a reduction in the maximum mass of slabs, their thickness increased to 300-350 mm.

Another feature of the third-generation SHSHP was the desire to expand the range of rolled strips in terms of thickness, both towards maximum and minimum values. It was on some of these mills that the rolling of strips with a thickness of 1-0.8 mm was started, which was briefly discussed in subsection 1 of this chapter.

Due to the increase in the thickness of slabs up to 355 mm, as well as the realization of the possibility of rolling strips with a thickness of 0.8-1 mm, it was planned to install 8 and 9 stands in the finishing group on a number of third-generation SHGS, bringing the rolling speed to 30.8 m/s and relative weight of rolls up to 36 t/m strip width.

It turned out that the main reason for this idea was that at that time the capacity of cold rolling mills in Japan was not enough. When such mills appeared in Japan, the rolling of strips with a thickness of less than 1.2 mm was stopped on the SHGP, the 8th and 9th stands in the finishing group were not installed on any SHGP in the world and the rolling speed of up to 30 m/s was not achieved. .

ShSGP of the third generation in the USSR were mills 2000 of OJSC Novolipetsk Metallurgical Plant (NLMK) and OJSC Severstal, put into operation in 1969 and 1974, respectively. The mills provide for the rolling of strips with a thickness of 1.2-16 mm and a width of up to 1850 mm from slabs weighing up to 36 tons and maximum rolling speeds of up to 20-21 m/s.

The difference between them is that the location of the roughing stands at the NLMK mill 2000 is traditional - discontinuous (Fig. 30), while at the Severstal mill 2000 the last three stands are combined into a continuous roughing subgroup (three stands for the first time in the world). Another difference between these mills is that the length of the discharge roller table on NLMK's 2000 mill is 206,700 mm, and on Severstal's 2000 mill, 97,500 mm. The approach of the winders on the mill 2000 of OAO Severstal to the last stand of the finishing group made it possible to reduce the time of rolling the front part of the strips at low speed. Reducing the temperature of winding thick strips is achieved by increasing the distance between the first and second groups of winders. Both mills have a capacity of 6 million tons per year.

Fig.30. The layout of the main equipment of the continuous ShSGP 2000 of OJSC NLMK: 1 - furnace roller table; 2 – trolley for transferring slabs; 3 – slab pushers; 4 - heating methodical furnaces; 5 - receiving roller table; 6 – receiver of heated slabs; 7 - vertical scale breaker (VOK); 8 - two-roll stand; 9 - universal four-roll stands; 10 - intermediate roller table; 11 – flying scissors; 12 - conveyor for the head and bottom trim; 13 – finishing two-roll scale breaker; 14 – finishing four-roll stands; 15 - discharge roller table; 16 - winders for winding thin strips; 17 - conveyors; 18 - lifting and rotary table; 19 - winders for winding thick strips; 20 - roll storage and sheet finishing department

The operating experience of the third generation SHGP has shown that the expansion of the range of rolled strips and the increase in the mass of slabs cause an increase in the mass of equipment, and, consequently, the cost of the mill and workshop, lengthening of the production line of the mill (up to 750 m), expansion of the assortment of strips in thickness up to 0.8 mm , create difficulties in maintaining the required temperature conditions of rolling, cause inefficient use of the mill equipment (when rolling strips with a thickness of more than 12-16 mm and a width of less than 1500 mm, it is used at about 30% of its capacity). In addition, strips with a thickness of 0.8–1 mm were significantly inferior to cold-rolled strips of the same thickness in terms of rolling accuracy, mechanical properties, surface quality, and presentation.

In connection with indicated shortcomings, as well as the high cost (over 500 million euros) of the third generation SHGP, the fourth generation SHGP appeared.

Their main distinctive feature was the installation of a universal reversible stand in the roughing group of stands, which increased the crimping capacity and reduced the length of the roughing group of stands.

In addition to the reverse stand, there are four more universal stands in the roughing group, two of which (the last ones) are combined into a continuous roughing subgroup. A number of mills of the fourth generation used intermediate rewinders, which will be discussed later. Representatives of the fourth generation SHGP is the Baostill 2050 mill, the equipment layout of which is shown in Fig.31.

Mill 2050 began operating in 1989. It is designed for rolling strips 1.2-25.4 mm thick and 600-1900 mm wide. Maximum coil weight 44.5 tons, rolling speed up to 25 m/s, annual production 4 million tons.

characteristic feature the mill is the presence in the roughing group of stands of two reversible universal stands (the first is a duo, the second is a quarto) and the union of the remaining two stands into a continuous subgroup. There are seven quarto stands in the finishing group. Mill 2050 has one group of coilers. In the roughing group of stands, it is possible to reduce and adjust the width of the rolls. Reducing is carried out in the first roughing universal stand, which has a powerful stand with vertical rolls (for three passes it is 150 mm), and the width is adjusted in all other stands of the roughing group by reducing the rolled stock in vertical rolls.

Fig.31. The layout of the main equipment of the 3/4-continuous ShSGP 2050 "Baostill": 1 - furnace roller table; 2 – slab pushers; 3 - heating methodical furnaces with walking beams; 4 – slab dispensing device; 5 - receiving roller table; 6 - two-roll universal reversible stand; 7 - four-roll universal reversible stand; 8 - four-roll universal non-reversible stands combined into a continuous roughing subgroup; 9 - intermediate roller table; 10 - heat-insulating lifting screen; 11 - crank shears; 12 - roller guide wiring; 13 - finishing continuous group of four-roll stands; 14 – discharge roller table; 15 - shower installation; 16 - winders; 17 - adjusting

These mills are called 3/4-continuous SHSHP.

It should be noted that 3/4-continuous mills are currently considered the most modern and efficient.

The desire to use hot-rolled (cheaper) sheet instead of cold-rolled sheet led to the creation of SHSHP, the assortment of which includes strips with a thickness of 0.8-25 mm and a width of 600-1850 mm (Fig. 32). This became possible due to more advanced automation systems, the use of intermediate rewinders, a press for reducing slabs and removing their taper.

These mills are called "endless rolling mills". They are assigned by us to the fifth generation.

In fact, endless rolling mills are 3/4-continuous, but their difference is the installation of a machine for welding rolls on the intermediate roller table.

The welding machine consists of scissors intended for trimming the ends of the rolls, a system for centering the rolls, clamps for holding the rolls during heating and upsetting, an inductor, a mechanism for compressing the welded ends of the rolls and a deburring device. The full cycle of rolling, positioning, heating and welding of the ends is 20-40 minutes.

The length of the welding section with equipment located on it is 12, the height and width are 6 m each. The cost of the welding section with peripheral equipment is approximately 114 million dollars, and the cost of the mill is more than 1 billion US dollars. Such a huge cost is due to the presence at the mill of almost all possible equipment for SHGP and a complex of automation systems, often duplicating each other. The allowable rolling force in the stands of the roughing and finishing groups is in the range of 38-50 MN.

Fig.32. The layout of the main equipment of the ShSGP 2050 by Kawasaki Steel (Japan):

1 - heating furnaces; 2 – press for width reduction of slabs; 3 – reversible stand duo; 4 - draft stands quarto; 5 - PPU; 6 - scissors; 7 - strip welding area; 8 - section for heating the edges, trimming the ends and churning off the scale; 9 – finishing group of stands; 10 - shower installation; 11 - dividing scissors; 12 - device for pressing the strip to the roller table; 13 - winders

In the endless rolling mode, strips are produced with the dimensions shown in Fig. 33. The mill achieved high accuracy of rolling strips in thickness and width, high flatness. Welding strips (up to 15 pieces) into an “endless” strip allows maintaining a high and constant rolling speed, which causes many positive aspects.

The practice of operating such mills has shown that they can roll strips with a minimum thickness of 0.8 mm with high accuracy, practically eliminate transitional modes of entry-exit of the ends of the strips, accompanied by a decrease in the rolling speed followed by rolling of the strips with acceleration, as well as dangerous from the point of view of possible band jams.

However, some issues with endless rolling have not yet been resolved, and it has the following disadvantages:

– the impossibility of rolling in an endless mode for more than 15 strips due to an increase in the temperature of the rolls and a change in their thermal convexity;

– the need to start rolling from strips with a thickness of 2-2.5 mm, and then make a dynamic restructuring of the mill during rolling sequentially to a thickness of 1.5 - 1.2 - 1 - 0.8 mm, which leads to the production of strips of different thicknesses;

– high cost of the mill (more than 1 billion US dollars, including the welding section – 114 million US dollars).

All three continuous rolling mills are in operation in Japan. In our opinion, this dead end road development of the SHSP. The task of obtaining strips with a thickness of less than 1.2 mm can be solved much more easily in casting and rolling units (see below).

Rolling schemes

Earlier it was said that at the first generation SHGP, a preliminary breakdown of the width was envisaged due to the lack of slabs of sufficient width. At present, the possibilities of casting slabs at the continuous casting machine have made it possible to completely solve this problem. Therefore, only longitudinal rolling pattern.

Rolling of metal in roughing and finishing groups of stands

The number, type and nature of the location of the stands depend on the type of SHGP. The main changes at the GSGP are related to the roughing group. The common feature is the presence of scale breakers with horizontal or vertical rolls (VOK). Initially they were used to break scale, then they began to be used to adjust the width of slabs.

With the transition of SHGP to continuously cast billets, some difficulties arose in organizing the production of strips of the entire range of widths. On ShSGP, strips are usually rolled with a width of gradation of 20-40 mm. Upon receipt of rolled slabs from slabs or blooming slabs, it was possible to order their rolling with any gradation in width.

On the CCM slabs are cast with a width corresponding to the width of the installed mold. When an enterprise has a lot of continuous casting machines, each of them can be specialized in casting slabs of 3-4 sizes in width. If there are only 2-3 CCMs, then there is a need for frequent replacement of the mold, and consequently, there are losses in productivity, metal, and the quality of slabs deteriorates during periods of non-stationary casting.

This problem is solved in different ways. Firstly, molds with a changing position of the end walls are used directly in the CCM. This method has a number of disadvantages - complication of the design of the mold, violation of the casting regime, and, consequently, loss of production, deterioration of the quality of the metal, casting of slabs of variable width.

Secondly, FOC is used both to reduce the width of slabs and to eliminate the wedge shape of slabs.

So, on the Baostill mill 2050 (see Fig. 31), two reversible stands are installed in the roughing group - one duo, the second quarto. Moreover, the duo stand is universal with powerful vertical rolls (electric motor power 3000 kW, roll diameter 1100 mm). The second stand (quarto) is also universal, but less powerful (drive power 2×600 kW, roll diameter 1000 mm). The next two universal quarto stands are located continuously at a distance of 12 m from each other, the drive power of the vertical rolls of each of the stands is 2×380 kW, the diameter of the rolls is 880 mm.

The universal stand duo allows you to reduce the slab by 120 mm in one pass. Moreover, the scheme of slab compression, and then the roll, looks like this: VV-GV-GV-VV-VV-GV. Thus, the formed sags at the edges of the roll are rolled out in horizontal rolls, and then two passes in a row in the vertical rolls of the same stand and again rolling in horizontal rolls follow.

In the case of reverse rolling in the second stand, the scheme of rolling in explosives and hot-waters looks similar. But the possibilities for compressing the roll in width are already much less. In the third and fourth universal stands one pass is made.

The main disadvantages when reducing slabs in vertical rolls

Limitation of the amount of compression according to the conditions of capture, which necessitates a multi-pass process;

The appearance of edge thickenings, which, during subsequent rolling in horizontal rolls, again (by about 60-70%) pass into the width of the roll;

The efficiency of roll reduction in vertical rolls is significantly increased if box gauges are used. But this raises a number of complications:

The need to replace rolls when the thickness of the original slabs changes;

The complexity of cutting calibers on rolls of large diameter;

Increased wear of calibrated rolls compared to smooth rolls;

Increased energy consumption for rolling.

Thirdly, the use of presses. Since the length of slabs on modern SHSHP reaches 15 m, the press performs step-by-step compression of the slab (Fig. 34). During compression by the strikers of the press, the slab is held by rulers, and after each single compression it moves along the process flow line.

A state-of-the-art slab reduction press is installed at the Thyssen Stahl SHG in Beckerwerth.

Technical characteristics of the press

The cycle time of one pass is 2 s. The formation of a thickening on the slab during its processing in the press does not cause any difficulties during further rolling in the roughing reversing stand of the mill. These thickenings are much smaller than when reducing slabs in vertical rolls.

new technical solution in the draft group, the union of the last two or three stands into a continuous subgroup has also become. For the first time in the world, three stands were combined into a continuous subgroup at the mill 2000 of OAO Severstal (designer and manufacturer of the mill ZAO NKMZ).

The layout of the stands in this subgroup is shown in Fig.35.

Stand 3 has a roll drive from two DC electric motors with a power of 2x6300 kW (110/240 rpm) through a common gearbox and gear stand. The fourth stand has a similar drive. The fifth stand has a gearless drive from a 2×6300 kW (55/140 rpm) two-arm DC electric motor through a gear stand. The maximum allowable rolling force in stands with horizontal rolls is 33 MN, with vertical rolls 2.6 MN.

The applied drive allows you to adjust the rolling speed in the complex.

The use of a continuous subgroup of stands made it possible to:

– reduce the length of the roughing group of the mill by 50 m, as well as the length of the workshop and roller tables, and, consequently, their cost;

– to improve the temperature regime of rolling by reducing the cooling time of the rolls and increasing the rolling speed to 5 m/s.

Draft stand group should provide

1. The specified roll thickness.

2. A given width of the roll with a minimum variation in width.

3. Required rolling temperature.

The finishing group of stands is always continuous. Some changes have been made to its head section. For a long time, drum shears were used before the finishing stand.

On the new ShSGP, instead of drum shears, crank shears began to be used. Compared to drum shears, thicker rolls can be cut with them, and they have a longer blade life. So, on the Baostill mill 2050, it is possible to cut a roll with a section of 65 × 1900 mm from X70 steel. The maximum cutting force reaches 11 MN, the durability of the knives is 10 times higher than that of drum shears. An optimization system has been installed that ensures minimal loss of metal in trimming.

At the SHGP of the 1st generation, a two-roll stand was used as a finishing scale breaker. Since the reduction in the finishing scale breaker was 0.2-0.4 mm, the stand itself and its drive were low-power, and spring cups were installed between the pressure screws and the pads of the upper rolls. In this case, the pressure on the roll was created by the force of compressed springs and the mass of the upper roll with pillows.

An increase in the mass of slabs, an expansion of the range of SHSHP, an increase in the requirements for the quality of hot-rolled strips (including surface quality) led to the installation of more powerful finishing scale breakers driven by electric motors with a power of 350-400 kW, springs were installed under the pressure screws with force up to 294 kN. The mass of such scale breakers reached 200-300 tons.

The next step was the transition to the use of roller finishing scale breakers, in which the rollers are pressed against the roll with a force of 20-98 kN. For example, in CJSC NKMZ, during the reconstruction of the mill 2000 of OJSC Severstal, a roller scale breaker was designed, manufactured and put into operation.

In the scale breaker of this design, there are two pairs of pressure rollers with a diameter of 500 mm, which, with the help of springs and a lever system, are pressed against the roll and destroy the scale on the roll. This is followed by transport rollers, between which two rows of collectors with hydrodescaling nozzles are installed. Squeeze rollers are installed at the outlet of the scale breaker, which squeeze water from the roll. The mass of the scale breaker does not exceed 50-80 tons.

In the finishing group of stands, four-row bearings with tapered rollers for work rolls and fluid friction bearings for back-up rolls are used.

Since the beginning of the 70s of the last century, the use of hydraulic pressure (with the preservation of electromechanical pressure) devices began in the finishing group of stands.

At the beginning of the 1980s, for the first time in the world, in Japan, six-roll stands of a special design were used for hot strip rolling, with the possibility of axial displacement of the work and intermediate rolls. However, they were mainly used in Japan. They have not received wide distribution.

Finishing group of stands should provide

1. Specified strip dimensions.

2. The specified metal quality in terms of accuracy, including flatness, surface quality and mechanical properties.