In modern conditions before metallurgists there is a problem of reception first of all to qualitative production, thus not reducing volume of manufacture. They face such problems:

• The extremely out-of-date equipment;
• Low productivity of rolling mills of Ukraine, In comparison with mill other more advanced countries;
• Poor quality of production;
• Absence of means for reconstruction;

The basic directions of development of rolling manufacture became transition to unified continuously cast preparation and Reconstruction working станов with the purpose of increase of their technological level, Which provides the minimal material, power and labour expenses at high quality of production. The analysis of the technical literature has shown, that in the basic way of decrease material and power expenses by manufacture Hire - there is a transition on molten Preparation of the increased section and weights.

On Open Society "EMZ" there is a modern way of manufacture began (converter) and her розливки (two modern МБЛЗ), but rolling manufacture Out-of-date (three technically worn out high-quality стана and started in the beginning of 60th years wire стан, Which demands reconstruction).

Now on Open Society "EMZ" two work high-quality МНЛЗ which cast preparations by section 150*150 of mm, 125*125 mm and 100*100 mm. For use on a status of 250 preparations by section 150*150 of mm of him it is necessary to reconstruct. But on it there are no means. Therefore we offer to consider variants of association in uniform complex MNLZ and mill 250.

Such combination will allow to leave on higher degree of quality of finished goods and to raise its competitiveness

PROSPECTS OF DEVELOPMENT

Now in the advanced countries wide application has received spill steel on МНЛЗ. So in Europe about 90 % of all sucelted steel it is spilled on МНЛЗ, However in Ukraine only about 20 % of steel spill in such a way.

On Open Society EMZ two are entered into operation modern high-quality MNLZ.В the structure a factory has mill 250, Which issues competitive production. But стан has such lacks:

• Low speed proskating rinks
• Small weight of revolt
• Presence of two heating furnaces
• Initial preparation of small section

The existing circuit of manufacture morally also is technically obsolete, And it does production of a factory of less competitive. As is shown above, at present on стане 250 use preparation by section 80*80 of mm. On entered into operation MNLZ the minimal section of cast preparation 100*100 mm. That is without reconstruction mill 250 to translate it on molten preparation it is impossible. GIPROSTAL and firm " СКЕТ " the developed variants of reconstruction. Thus both variants provide installation of group before already existing draft group (in the first variant 6 cages, in the second 5 cages). Such reconstruction demands the big expenses (installation only groups клетей 10-15 million USD). Possible variants reduction molten preparations directly for MNLZ. We suggest to consider two variants. The first variant are uses for pressure reduction RER-process (a proskating rink{proroll} of simple structures on smooth rolls). The second variant - pressure reduction preparations with application cages existing NZS 850/610/550. is offered to consider both variants.

The first variant this use beskalibrovoi rollihg. Last years has abroad received a wide circulation a way proskating rinks of simple structures on smooth rolls (RER-process) with the help обжатия прямкосинця or in alternating vertical and horizontal smooth rolls, Or in smooth horizontal rolls with canting on 90 ° after each miss. However despite of known advantages, the technology proskating rinks has not found wide application because of necessity Often canting and a smaller extract for the miss in comparison with rolling in calibres. Despite of advantages technologies proskating rinks in calibrated rolls, There were established lacks which significally reduce a production efficiency of high-quality hire. It is possible to attribute to these lacks:

• Complexity of preparation rolls - for cutting strands on rolls necessary plotting of patterns, Own patterns, counterpatterns and special the measuring tool; Cutting strand carry out several cutters of the complex form, Own cutting trickles - process with low productivity and the big loss of a material with a shaving (up to 15 % from weight it is shaky);
• Complexity of adjustment rolls - necessary exact installation rolls in an axial direction, Coaxially introductory, lead-in armatures and calibre; These operations demand rather big expenses of time and high qualification of the personnel, As the least discrepancy tuning up promotes education on a strip of different defects;
• Non-uniformity of deformation of metal in calibres - the reason Occurrences of defects on a strip and the raised deterioration rolls;
• Small service life валков because of the raised deterioration Calibres and low operating ratio of length flanks rolls.

Researches show, that in draft cage preparation and high-quality mills clamp on rolls Borrow 10-60 % of length flanks rolls; it is long on rolls averages 17-28 % From diameter flanks that considerably cage reduces durability rolls and term of their service; Therefore on these mills on each worker have 2-4 a stock rolls at full Absence of interchangeability rolls different cages. The specified lacks are the reason of high expenses at a traditional way proskating rinks. Proskating rinks of high-quality structures it is possible to count alternative way a way proskating rinks (BKP), Which will be, that in draft and intermediate клетях high-quality and preparation statuses Use are shaky with smooth roll and only in fair cages calibrated are shaky for formation Ready structure. Proskating rinks widely apply this way abroad by manufacture of preparations, High-quality structures of the simple form, armatures. In way BKP make hire with carbonaceous, Alloyed, automatic, spring, and alloys from copper, Aluminium and their alloys, which in the continuous way and in steel molds. proskating rinks in blooming group cage entered technology stage by stage since 1991. On стане 150 metallurgical combine and at present apply in all six клетях groups. Introduction of way BKP the raised expansion of metal at proskating rinks in rolls with smooth In comparison with rolling in calibres, and also low stability of a peal. On a basis analytically experimental researches there were developed principles of calculation of modes compression, Which provide the maximal extract at the minimal expansion. Besides the lead analysis Stability rectangular in rolls with smooth roll has allowed will establish power influences on introductory armature and to develop a technique of its calculation and designing. As a result of it rational modes proskating rinks have been developed, And also a design of introduction armature which allows to exclude entirely a peal. As a result of the lead jobs proskating rinks successfully apply the given technology on mill, Peals had the correct form cross-section the parties, Which not compression, minimal. At hire entirely excluded such defects as "wrinkles", etc.

On a number with a variant proskating rinks in the given job by us are offered to be considered Detailed use cage NZS 850/610/550 Open Societies " ЕМZ ". Proskating rink in calibres is well investigated and stable process. For today there is a plenty of design procedures of modes compression, Calibrations and power parameters of the given process. All this allows with the big accuracy To pay off receptions of preparation of necessary section. Advantages of the given variant will consist:

• Process is well investigated and there are techniques which give excellent effect calculations compressions, The sizes of calibres, power parameters;
• At a factory there is a necessary technological equipment for realization of this process;
• This variant does not demand the big capital expenses.

Us was make calculation of conditions of capture, power parameters. These calculations have shown that probably use of four mills for НЗС 850/610/550 For reduction of section of preparation about 150*150 mm up to section 80*80 of mm. Section of cast preparation of 150*150 mm Is chosen not casually. It will allow to have the minimal park of expensive crystallizers. Precomputations покозали that at разливке from 6 brooks will be used only 4, And steel preparation will be realized as commodity.

In the job I carry out research of an opportunity use compression on smooth a flank and compression calibres. We spend experiment on laboratory mills 100. For modelling metal in hot Status we had been took plasticine and lead. For a basis preparation of 150*150 mm and diameter rolls mill 150 metallurgical has been taken Combine. At present experiment proceeds and to speak about his results early

CONCLUSIONS

After the analysis of the information us be offered such circuit of a site for reduce preparations.

The main task of my job - show an opportunity of increase of productivity mill, Decrease in the cost price of production, increase of its competitiveness without essential expenses. Probably for our factories for overcome crisis position also are necessary such pass reconstruction.

THE LIST OF THE USED SOURCES

1.Чекмарев А.П., Мутьев М.С., Машковец Р.А. Калибровка прокатных валков. - М.: Металлургия, 1971.- 509с..

2.Бахтинов Б.П., Штернов М.М. Калибровка прокатных валков.- М.: Металлургия, 1953. - 783с.

3.Бахтинов Ю.Б. О путях усовершенствования произвотства сортових заготовок// Произвотство проката.–2000.-№2–С.14-19

4.Прокатные станы. Справочник. В трех томах. М.: Металлургия, 1992.

5. Кандауров Л.Е.Развитие теории и практики бескалибровой прокатки заготовок прямоугольного сечения// Магнитогорск: металлургия, 2002