ROLLING

MODERN ROLLING MILLS AND THEIR E Q U I P M E N T

G. L. K h i m i c h and A. V. T r e t ' y a k o v

Scientific Research Institute of Heavy Machinery of the Ural Machine Building Plant Translated fromMetallurg, No. 6, pp. 22-25, June, 1968

The 22rid Congress of our Party has pointed out clear pathways for the development of the Soviet society inthe next two decades (1961-1980). In 1980 the metallurgical industry of our country will achieve a level at which we can produce annually about 280 millions tons of steel. During this time it is necessary to build many new unique rolling machines. If we take into account the need for mechanization and automation of rolled goods production in the existing shops, additional equipment will be needed for reconstruction of the present mills.

Continuous processes of rolled goods production ensures a considerable increase in the output of mills and reli- able, relatively cheap large-scale mechanization and automation. The experience of the Ural Machine Building Plant shows that only large-scale mechanization of the entire production process on the rail and structural mills will make it possibIe to double the specific productivity of one ton of installed mechanical equipment and also double it on the blooming mills in comparison with the present blooming mills with manual remote control.

In addition, large-scale mechanization and automation of rolled goods production ensures an improvement in the quality of the products, reduces the cost of its manufacture, facilitates and appreciably changes the character of the labor of the workers, and fosters an increase in their cultural and technical level.

However, a further wide introduction of large-scale mechanization and automation in the roiling industry re- quires, in our opinion, the solution of the following important problems:

1) Mechanization and automation of individual operations (quality control; dressing, packing, transportation, and loading of the finished products);

2) automation not only of the technological processes but aiso of the control processes and production organi- zation;

3) the creation of the means of control and administration needed for this purpose, Our plans call for carrying out works to solve all these problems.

The collective of the Ural Machine Building Plant is working to further improve and devetop new rolling mills and their equipment.

The following works were carried out in 1962:

!. The development of the 1300 blooming mill with large-scale mechanization and automation of the produc- tion processes, having very high technical and economic indexes (table).

2. Outfitting of the cold rolling shop for automobile sheet with a continuous four-stand 1700 mill; the rolling rate is up to 25 m/sec. The mill is extensively mechanized and partially automated. The equipment of one mill is already in use at the Cherepovetskii Metallurgical Plant; another mill is presently being assembled at the II'ich Zhda- novskii Plant.

3. The introduction of the circular system of delivering heated ingots to the blooming and slabbing mills, which has already been adopted by the Nizhne-Tagil Metallurgical Combine after reconstruction of the 1150 blooming mill. The entire delivery cycle lasts 30-35 see. The output of the blooming mill after reconstruction increased about 25%.

4. A system was developed for measuring the temperature of the working roils of the cold-rolling mills which operate at rates up to 10 m/sec. This work is continuing toward the development of a reliable system for measuring the temperature of rolls for high-speed rolling mills, which will considerably increase the quality of rolled products and the output of suitable products.

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Comparison of the Output of Two Blooming Mills

Indexes Blooming Blooming mil l 1150 mil l 1300

Specific annual productivity re la t ive to one ton of instal led mechanica l equipment, t / t . . . . . . . . . . . . . . . . . . . . . . .

Same, re la t ive to the power of the installed e lec t r ic motors

in horsepower, t / t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Annual productivity of labor of one man working on the

blooming mi l l , t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cost of converting one ton of finished product, rubles . . . . . . .

500

138

10740

1.58

1050

200

18900 1.37

Work is presently being carried out for the la rge-sca le mechaniza t ion and automat ion of roiling processes, their continuity, increase of the operat ional re l iab i l i ty of the equipment, increase of specific output and economy of mi l l operation, and improvement of the working conditions of the workers.

In 1963 most efforts are going into the reconstruction of the blooming mills of the Cherepovetskii Plant and

of others.

The Ural Machine Building Plant is to master the production of devices for continuous teeming of steel and to outfit a l l of our meta l lurg ica l plants with these devices. Taking into account that this type of equipment is s t i l lvery far from perfect, we have planned a number of experimental design works which when carried out wil l open broad

possibilities even this year.

The year 1963 will also see the complet ion of the work on developing equipment for the production of railroad rafts with the ra i l heads hardened over the entire surface by the methods of bulk oil quenching with subsequent t em- pering and surface hardening by heating them with high-frequency currents. An exper imental use of rails thus treated showed that their l ife was increased by a factor of 2-2.5 in comparison with rails manufactured by the presently exist- ing technology.

The work will be comptetod on the development of equipment for e lec t r ic welding of short rails to rails of standard length. The development of this equipment wit1 make possible an 8-12% increase in the output of suitabte

products in the ra i l - ro i l ing shops.

An important work that should be completed this year by the Ural Machine Building Plant in conjunction with the Al l -Union Scient i f ic Research Institute of Meta l lurgica l Machinery and other planning organizations is the deve l -

Five-stand cold-rol l ing mi l l .

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opment of the highly productive continuous medium-section 450 mill for a number of metallurgical plants of the Soviet Union. For the first time in world practice it is planned to accomplish on this mill a completely continuous process of roiling medium-section irregular shapes with the possibility of using a regime of infinite rolling by welding the workpieces before heating them in the high-speed sectional furnaces. On the mill both the basic and the finishing operations will be highly mechanized and automated, thus ensuring its high productivity.

Presently an investigation is being carried out on a method for continuous hardening of sheets with a determina- tion of the design and parameters of the hardening machine. For this purpose a model of a hardening machine has been designed, fabricated and is undergoing thorough investigation. Sheets of ordinary carbon steels which have undergone hardening can reduce the weight of metal structures by 15-20% in comparison with similar articles made of ordinary carbon steel without heat-treating. The physicomechanical properties of heat-treated sheets are equal to sheets of more expensive steels.

The work done in this area allows us to hope for the possibility of the widespread use of hardening heat-treat- ment on rolled sections.

The development of equipment for the production of cold-rolled strip and sheet from special steels, heat- resistant, stainless, and others with high mechanical properties is destined for the cold-rolling mills. This equipment includes high-speed four-high mills and twenty-roll continuous units for descaling and heat-treating strip, straighten- ing and trimming, grinding and polishing of strip and sheet. This group of equipment is being developed in the Soviet Union for the first time and many of its units and machines are original.

Along with this, work is continuing to create a shop for continuous cold-rolling of strip. A modern cold-rolling shop is a complex of individual highly mechanized and automated units designed to perform a few of the many opera- tions of the production process- pickling, rolling, annealing, coating, straightening, trimming, etc. After treating the strip on each of these units the continuity of the production flow is disrupted and the connection between units is maintained by intermediate warehouses for semifinished goods.

A continuous connection between individual units will eliminate warehouses, reduce transportation means in the cold-rolling shops and appreciably increase the output per unit area of shop, increase the productivity of labor, and reduce the number of workers.

Urgent experimental design works and research themes needed to solve the problems of creating an automated shop for continuous cold-rolling have already been pointed out: the investigation of the temperature conditions of roll operation and the development of an automatic system for the delivery of emulsion to the rolls to maintain their con- stant temperature while rolling, an investigation of factors influencing the life of rolls, and the development of means to increase it.

Guillotine shears with a hydraulic drive.

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In 1962 gui l lot ine shears with a hydraulic drive of 650 tons pressure was designed and began to be manufac- tured. The cutting angle can be varied widely owing to the use of an original hydraulic system. As a result i tshould be possible to cut sheets of various thickness at opt imal cutting angles with the maximum ut i l iza t ion of capaci ty and a simultaneous improvement in cutting quali ty.

Work will also continue on the replacement of the furnace rollers of the hea t - t rea tment furnaces of the sheet mil ls by rollers with a facing of heat-res is tant reinforced concrete. The introduction of this measure when setting up the hea t - t rea t ing department of a sheet mi l l can yield a savings of 50 tons of nickel and 60tons of chromium.

The central p lace in the plan of our works is occupied by the problems of the mechaniza t ion and automation of the laborious processes of quali ty control, conditioning, packing, and loading of finished goods. Work is continu- ing to develop various machines, mechanisms, and units: machines for flame-scarfing hot workpieces in the produc- tion l ine, lines for conditioning cold workpieces, machines for packaging rafts and sheets, units for packing cold- rolled coils and bundles of sheets. It is also planned to determine the mechanica l properties of metals and alloys re la t ive to reduction during cold- and hot-rol l ing.

The designers and researchers of the Scientif ic Research Institute of Heavy Machinery of the Urai Machine Building Plant, inspired by the resolutions of the November (1962) Plenum of the Central Commit tee of the CPSU, will uncondit ionally fulfill on t ime and with quality the entire program of planned works.

AN I N C R E A S E IN T H E P R O D U C T I V I T Y OF THE T H R E E - H I G H M I L L

A . D . V e i s b e i n , E. A . D e m i d o v i c h , a n d B. M . R o t m i s t r o v s k i i

Enakievo Metal lurgical Plant Translated fromMetal lurg, No. 6, pp. 25-27, June, 1963

The Lauth mi l l of our plant has a roll stand with rolls 700/600/700 rain in diameter; the middle roll is idle. The middle roll is !oad balanced and the upper roll is hydraul ica l ly balanced. The working rolls are regulated in the ver t ical by the housing screws, packing, and cotter; the drive of the housing screws is e lec t r ica l .

The roll stand was equipped with l ift ing tables: a t i l t ing table on the front side and a paral le l table on the rear side. The mi l l was driven through a two-cycle double-ac t ion gas engine operating on blast-furnace gas; the power of the gas engine was 1000 hp, the number of revolutions of the rolls was 65-90 per min. Between the pinion housing and the gas engine was a flywheel with a moment of 53,100 tm s,

After being roiled on the mi l l the sheet was straightened on the V-roller hot straightening machine, then trans- ferred to thehot - rackswi th the pul l -over gear, where it was inspected, turning it through 180 ~ and sent to the finishing department to be cut into measured lengths.

The mi l l roiled cast open-hear th ingots weight 885-720 kg of the following steels: MSt.0, MSt.2rirn, MSt.Srim, MSt.8, MSt.4, MSt.5 (GOST 380-60) and second-grade ship steelsSt.SS, St.4S (GOST 5521-50). The mil l was to roll sheets 4-10 mrn thick, 1000-1400 mm wide, and up to 6000-8000 m m long.

The mi l l was recent ly considerably modernized: a new three-zone continuous reheating furnace was constructed, the screwdown mechanism of the roll stand was improved, the idle rollers of the l if t ing tables were par t ia l ly replaced by driven ones, and a number of operations in the sheet-finishing sect ion were mechanized.

At the end of 1960 the gas engine of the mil l was replaced by an asynchronous motor with a power of 1100 kW and 290 rprn; between the motor and the pinion housing were instal led a reducer with a gear ratio of 4 and a flywheel weighing 20.68 ton. This ensured mi l l operation without a sharp drop in the number of revolutions of the motor. In addit ion, the distance over which the roiled piece was tossed was reduced with the use of an e lec t r ic motor, which helped to reduce the rolling t ime by reducing the intervals between passes.

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