The accuracy of the roiled goods on the No. 2 300-mi l l equipped with ro l l e r -con tac t beatings is higher than on the No. 1 300-mi l l and the 350-mi l l operat ing on tex to l i te bearings.

Regardless of the type of mi l l or its equipment, a regular increase in the accuracy of the rolled goods is ob- served with an increase in the d iamete r of the round.

T H E L A T E S T IN R O L L I N G M I L L U N I T S

A T T H E C H E L Y A B I N S K

M E T A L L U R G I C A L P L A N T

L. V. L e b e d e v a

Roll-Pass Designer

Translated from Metal lurg, No. 4,

pp. 31-33, April , 1963

Owing to the growing demand for surface quali ty and accuracy of shapes and an increase in the output of mil ls , in recent years our plant has replaced the sliding friction roller guide units on the section mills with rolling friction rol ler guide units. At the same t ime the repeaters have been mastered.

Only after the introduct ion of the new roller guide was i t possible to use the finishing repeater for del iver ing the

oval to the round on the No. 1 300 mi l l . At present a f inishing repeater and the rol ler guide are being tried for two-

l ine roll ing on the 240 m111.

The l i ne - type 780 structural mi l l consists of three three-high mills . The mi l l rolls rounds with a d iameter of 90-180 mm at a rate of 2.8-2.5 m/ sec . In p lace of the box with smooth cas t - i ron guides which was previously used,

the finishing mi l l now has a box with roller guides (Fig. 1) which serves to del iver properly the leading edge of the

workpiece into the rolters and to take the shocks thus arising.

Various types of bearings have been tested on the mi l l . The double-row spherical roller bearing No. 3612, which withstands a higher load, showed i tself to be bet ter than the others. The bearings are lubricated thro.ugh the rol ler ax le from a hand station. When a sufficient amount of lubricant is del ivered, a portion of i t is squeezed be -

tween the housing and the cover and doses off access of water and scale.

Owing to ins ta l la t ion of the boxes with rol ler guides, the work of the rollers has been eased, del ivery of the

workpieces has become stable, deflect ions have stopped, there are no rejects, surface quali ty has improved, downtimes for changing guides has been reduced, se t -up of the mi l l has been s implif ied and acce le ra ted , the consumption of guides per ton of finished rolled product has been reduced (the l i fe of the roller boxes is about 5000-6000 t, whereas

for a pair of cas t - i ron guides i t was about 150-400 t), and the output of the mi l l has been increased.

The No. 2 300 mil l , a continuous l igh t - sec t ion mil l , consists of 15 stands arranged in two trains. The mi l l rolls

rounds with a d iamete r of 14-30 ram, armature steel No. 14-26, springs, and au tomobi le lock rings 8.5 V-26. The

rol l ing rate of the rounds, armature steel, and other shapes on the finishing stand is 5-12 m/sec .

On the I and III stands of the roughing train with box passes, guide boxes open at the top have been instal led

for de l iver ing the p iece when roll ing a l l shapes; the finishing train for rol! ing strip, springs, and lock rims has guides

with covers and passes with side adjusting bolts, a del ivery guide and guard u n i t - b o x e s with suspended upper and

lower guides.

The working part on the ent ire entry guide unit has been shortened; the receiving part has been lengthened and

widened, thus putt ing an end to " r amming" of the strip.

Boxes with rol ler guides (Fig. 2) made with one pair of rollers are instal led on the stands of the finishing train

and on the II and V stands of the roughing mi l l when roil ing rounds and armature s teel .

180

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Fig. 1. Box with roller passes on the finishing stand of the 780 mill: 1) Box; 2) roller container; 3) cam; 4) set screw; 5) roller; 6) roller bearing; 7 and 17) bushings; 8) roller axle; 9) cover; 10) special nut; 11) bolt; 12)adap- ter; 13) spring; 14 and 15) pipes for water supply; 16) washer.

The shape of the rollers for the finishing stand when rolling rounds is made with a radius equal to 0.9-0.95 Of the oval radius on the rolls; all other rollers are cylindrical. Usually the rollers can take 3-7 regrindings. One pair of finishing rollers made of steel KhG (with regrinding) can roll up to 5000 t of metal, i.e., they last 3-4 days; on the other stands of the finishing train the cylindrical rollers (with regrinding) last from four days to four or five weeks. On the V stand the rollers made of steel 45 last up to three weeks and on the II stand, more than three weeks. The rol- lers with the cylindrical surface for the finishing stand last without replacement until the pass grooves are worn out when rolling recurrent shapes.

After the V stand, where it is necessary to turn the square through 45*, a square tube-guide with adjustable rol- lers at the end of the guide was installed. The necessary angle of turning is established by turning the rollers relative to the tube. With the installation of the turning tube it was no longer necessary to turn the piece by axial displace- merit of the rolls and the required accuracy of delivery was ensured.

After the I, IV, and VI stands, where turning through 90 ~ is required, twist rolls have been installed in place of the helicoidal guides; the base of the twist rolls has been bolted to the bases of the working stands.

181

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LL+F - - u ,~ I ~:. ~.LN'.Nt.Tk~7 ~ t 5 . . . . ~ - - +'+ - + . . . . . . + + 0 - - -

Dril l 4 mm d iame te r opening M 3 under cam andJ a notch under bolt M 6 when mounting

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Fig. 2. Box with roller guides for the finishing stand of the No. 2 300 mi l l : 1) Box; 2)square bushing; ,q) guides; 4) receiv ing funnel; 5 and 7) roller containers; 6) spring; 8) stopping device ; 9) cam; 10) screw; 11) conica l pin; 12) set screw; 13) rol ler; 14) roller bearing; 15) spring col lar ; 16) bushing; 17) lubricat ing tube.

The angle of turning is regulated by d isp lacement of the rolls ax ia l ly by means of support plates and bolts and ve r t i ca l ly by the screw-down mechanism (spring balancing of the upper roll).

The ins ta l la t ion of the twist rolls has made i t possible to ensure an accurate del ivery of the p iece into the pass of the next stand, to improve surface quali ty, and to reduce expenditures for guide units.

The No. 1 300 mi l l is a two-s tage tandem l igh t -sec t ion mi l l consisting of two lines. In the first l ine are two th ree-h igh stands with 530 mm diamete r rolls and in the second l ine are six var iable two-high stands with 300 mm d iame te r rolls. The mi l l rolls rounds with a d iamete r of 18-30 m m at a rate of 4.6-5 m/sec .

On the first l ine the workpiece is de l ivered from pass to pass by the roller tables, transfer tables, and man ipu la t - ors, then is fed to the 300 l ine along the discharge chute, where the p iece is transferred from stand to stand by the re- peaters, the use of which on the ent ire finishing l ine has become possible owing to the master ing of rolling in roller guides. Turning tubes with rollers have been instal led as the del ivery guide and guard unit on the stands of the 300 l ine.

During the ent ire operat ing t ime of the mi l l with the use of the roller guide unit we did not observe any b reak- downs, good surface qual i ty was secured, and rejects were apprec iably reduced.

The 350 mi l l is a two-s tage tandem med ium-sec t ion structural mi l l ; its first l ine consists of one three-h igh stand with 485 mm d iame te r rolls and the second l ine of the 350 mi l l consists of five double-stands with 390 mm d i - ameter rolls. The mi l l rolls rounds with a d iamete r of 30-70 ram; the rol l ing speed is 2 .6-3 m/sec .

An entry guide unit with roller guides was used on this mi l l for the first t ime at the plant. Its first l ine was left unchanged and on the second l ine, boxes with rol ler guides were instal led in p lace of the sliding friction cas t - i ron guides. The ma te r i a l of the rollers is spec ia l ly hea t - t r ea ted steel Khl0S2M. The l i fe of the finishing rollers is about 3000-4000 t of m e t a l when rol l ing rounds with a d iamete r of 30-60 ram. At first the rollers are set for roll ing rounds

182

30-32 mm in diameter, then they are reset for roiling larger diameter rounds (32-34 ram), etc. The life of the rol- lers is 15,000-20,000 t of metal when rolling rounds with a diameter of 60-70 ram.

The introduction of roller guides on the mill has made it possible to facili tate significantly the work of the roll operators, to ensure a high surface quality, to reduce rejects by about fourfold (from 0.27% to 0.07~ to decrease mill downtimes, and to increase its productivity.

It is necessary to accelerate the construction of a specialized plant for the production of guides. This would greatly reduce expenditures for the fabrication of guides and their adjustment, would ease the labor of the workers, re- duce downtimes, and increase the quality of production and the output of the mills.

HEROES OF OUR T I M E

S. S o k o l o v

Literary Contributor of the Newspaper "Chelyabinskii Metallurg" Translated from Metallurg, No. 4, pp. 34-35, April, 1963

It was e v e n i n g . . . Nikolai Danilovich was walking along the familiar streets of the city of metallurgists and with surprise, as if for the first time, he looked at the passers-by, glanced into the windows-people were hastening about their business, behind the windows it also was as usual, humdrum and simple, as if there had not been those happy moments which Ushakov had just experienced. Although Nikolai Danilovich clearly understood that no one suspected and could not even begin to suspect the gladness which overfilled him, he nevertheless was stightly offended.

Here he, Nikolai Danilovich Ushakov, had just experienced the happiest moments in his 35 years of life. Sev- eral minutes ago he had stood on the brightly lighted stage of the Palace of Culture and looked out into the overfilled

hall, from where friends and unknown people encourag- ingly smiled at him. They had arrived to participate in the discussion of an important p rob lem- the awarding of the honorable right to be called a shock-worker* and collective of communist labor.

Again and ~tgain he lives through these exciting moments. It is as if the chapters from the great book of life reveal to his eyes the years spent at the plant. No, they haven' t been spent in vain. If it hadn' t been for these almost twenty years, he would not be standing on the stage and the collective of the No. 1 300 mill would not be awarded the title "Unit of Communist Labor."

As a f if teen-year-old youth N. D. Ushakov had In the photograph (Ieft to right): Foreman L. Antipov, linked his destiny with the Chelyabinsk Metallurgical Mill chief N. Ushakov, senior roller A. Kazachenko. Plant. Here he learned to love work, here he finished

secondary school, and then the evening session of the Chelyabinsk Polytechnieal Institute. The industrial destiny of Nikolai Danilovich is interesting: fitter on rolling mills, two years later the supervisor of the brigade of the No. 1 300 mill, and after another two years the chief of the mill.

Full of impressions and glad thoughts, Nikolai Danilovich crossed the threshold of his apartment. It savored of domestic coziness and family happiness.

*Editor's note: "Shock" worker refers to one working above the specified rate.

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