ISSN 0967-0912, Steel in Translation, 2008, Vol. 38, No. 11, pp. 935–938. © Allerton Press, Inc., 2008.Original Russian Text © I.V. Nedorezov, E.G. Beloglazov, N.D. Nesterova, T.A. Mezrina, Yu.D. Makarov, 2008, published in “Stal’,” 2008, No. 11, pp. 108–110.

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It is standard practice at OOO Uralmash Engineer-ing to calculate the static strength and durability of roll-ing equipment, with the identification of weak spots inthe design. The demand for strength calculations ofKvarto four-high roller systems and the frames of exist-ing machine tools has increased recently, on account ofcustomers' desire to expand the range of products thatthey roll, increase the loads on the mills, and increasethe productivity, with minimal expenditures on recon-struction.

The load in mill cells is determined using originalsoftware for calculating the energy parameters in hotand cold rolling.

The Hot-Rolling Mill program permits estimatingof the rolling parameters on blooming, billet, rail,beam, large-rod and other mills. Specialized SGPLsoftware is used for calculations of the hot rolling ofthick sheet. In particular, it has been adapted and intro-duced

1

at the Kvarto-2800 four-high cell at OAOUral’skaya Stal (Fig. 1) [1].

ORKhP software is used for calculations of theenergy parameters and the optimal conditions of coldstrip rolling on continuous and reversible mills [2]. Theresults are used in the design, supply, installation, anddebugging of many Uralmash mills, which are now insuccessful operation. From available technologicalinformation, the program permits estimation of theactual frictional coefficients, which may then be used incalculating the rolling parameters on the reconstructedmill and the loads on its frame, roller system, and drive.

Strength calculations for newly designed, recon-structed, or existing equipment may be based onANSYS software, intended for the creation of three-dimensional models of parts or subassemblies and cal-culation of the stress-strain state, taking account of thecontact of the parts [3–5]. Strength calculations revealpoints of stress concentration, permit timely modifica-tion of the design, and are used to confirm the decreasein stress to acceptable levels, taking account of therequirements of the Gostekhnadzor State Inspectorate.

To estimate the fatigue and remaining life of millframes, we need to know the output levels and the prod-

1

With the assistance of V. M. Fel’dman, A. M. Stepashin, andE.V. Yakushev of OAO Ural’skaya Stal.

uct distribution in terms of thickness, width, and gradesof steel. Then the energy parameters and the maximumstresses are calculated, and the elapsed and remaininglife of the frame is estimated by the standard method(State Standard GOST 25.504–82) and other familiarmethods [6, 7]. These data permit judgments regardingthe optimal degree of reconstruction and the possibilityof rolling new products and/or increasing mill produc-tivity.

KVARTO-2800 CELL WITH A COMPOSITE FRAME (OAO URAL’SKAYA STAL)

The goal of this research

2

is to develop recommen-dations for the continued operation of the 40-year-oldKvarto-2800 four-high cell, in which the purchaser hasreplaced the motor. We want to know whether the pro-ductivity of the cell may be increased and how widelywe may use controlled sheet-rolling conditions charac-terized by reduced metal temperature and increasedforces and torques.

The energy parameters of rolling are calculated forordinary shop conditions and for conditions of con-trolled rolling. ANSYS software permits calculation ofthe contact problems and determination of the stress–strain state of the composite frame and the roller system(Fig. 2), as well as the universal spindles (Fig. 3), andreveals the points at which the load is greatest.

Then the durability is calculated and the remaininglife of the housing is estimated for different loads andproductivity levels. On the basis of results for the limit-ing technological loads and durability, recommenda-tions are made regarding the operation of the cell.

KVARTO-2800 CELL (OAO SEVERSTAL)

The calculations are conducted

3

within the frame-work of the modernization of the 44-year-old Kvarto-

2

With the participation of I. F. Voletov, Yu. P. Chistyakov,Yu. A. Strizhov, and M. A. Vaganov (OOO Uralmash Engineer-ing).

3

With the participation of E. Yu. Zhuravlev (Ural State TechnicalUniversity–Ural Polytechnic Institute), Yu. P. Chistyakov (OOOUralmash Engineering), V. I. Klopov, and L. M. Bobrov (OAOKO VNIImetmash).

Estimating the Strength and Remaining Life of Roller Mills

I. V. Nedorezov, E. G. Beloglazov, N. D. Nesterova, T. A. Mezrina, and Yu. D. Makarov

OOO Uralmash Engineering, Yekaterinburg, Russia

DOI:

10.3103/S0967091208110144

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2800 four-high cell by OAO KO VNIImetmash(St Petersburg), so as to increase the permissible rollingforce from 20 to 40 MN, without replacement of theframe.

Calculation of the stress–strain state and strength ofthe frame reveals two weak spots (Fig. 4). Then ordi-nary and controlled hot-rolling conditions for steelsheet are calculated, before and after modernization ofthe cell, with increase in the rolling force to 40 MN.Taking account of the results, the remaining life of theframe is calculated.

On the basis of the results, VNIImetmash specialistsconduct additional inspections of the frame and pre-scribe special treatment for the most hazardous spotunder the nut of the adjusting screw.

900 REDUCTION CELL (RAIL AND BEAM SHOP, OAO NKMK)

In this research,

4

the goal is to evaluate the need toreplace a German frame that is more than 50 years old.

First, the energy parameters for the hot rolling ofsome key products (R65 rails, 40 and 24 channels, 36Mbeams, 100 wheels, and DN-65 rail underlay) in shopconditions are estimated. Then, for the maximum roll-ing force obtained, ANSYS software is used to calcu-late the stress–strain state of the frame, taking accountof the adjacent parts (nut, screw, supporting plate), andthe points of greatest load are identified (Fig. 5).Finally, the life is calculated, and it is shown that theframe already operates in the second section of the

4

With the participation of E.Yu. Zhuravlev (Ural State TechnicalUniversity–Ural Polytechnic Institute), Yu.A. Strizhov, Yu.P. Chis-tyakov, V.N. Kuz’mov (OOO Uralmash Engineering), N.A. Ko-zyrev, and S.V. Makarov (OAO NKMK).

fatigue curve, which is practically horizontal for carbonsteel and corresponds to unlimited life.

ROLLER SYSTEM OF THE KVARTO-800 MILL (OAO SHCHELKOVSKII

METALLURGICHESKII ZAVOD)

The goal of this research

5

is to design a special rollersystem so as to expand the range of strip products rolledon the mill and increase the strip width. The strength ofexisting and special roller systems is calculated(Fig. 6), taking account of different strip widths, pro-files of the supporting and working rollers, and hydrau-lic flexure of the working rollers in cold rolling. Finally,a design is developed for a special roller system in

5

With the participation of N.A. Evdokimov, S.E. Gusev (OOOUralmash Engineering), V.I. Sidorkin, Yu.V. Tevs, E.Yu. Emel’ya-nov, and A.Yu. Dolzhenkov (OAO Shchelkovskii Metallur-gicheskii Zavod).

Load

Working roller

Bearing

2 44

5

A

B 4

1

4 5

43

45

6

1

5 4

4

2

ZX

Y

ZY

X

(a)

(b)

Fig. 2.

Basic parts and diagrams of composite Kvarto-2800cell and roller system at OAO Ural’skaya Stal: (

1

) housingbrace; (

2

) upper crossbar; (

3

) lower crossbar; (

4

) anchorring; (

5

) anchor rod; (

6

) lug; (

A

,

B

) zones of action of theload at the upper and lower crosspieces, respectively.

5550454035302520151050Rolling time, s

100008000600040002000

0–2000–4000–6000–8000

–10000

Measured current, A

Calculated current,

Measured speed, 100 rpm

Calculated current atmaximum acceleration, Adisregarding acceleration, A

Fig. 1.

Comparison of the motor currents in the Kvarto-2800 cell at OAO Ural’skaya Stal, according to measure-ments and the SGPL program [1].

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ESTIMATING THE STRENGTH AND REMAINING LIFE OF ROLLER MILLS 937

which the stress is even lower than in the existing sys-tem.

ROLLER SYSTEM OF THE KVARTO-1300 MILL (OAO VIZ-STAL)

The goal of this research

6

is to design a modernizedroller system so as to expand the range of strip productsand increase the strip width. Besides design calcula-tions and the development of cold-rolling conditionsfor new products, the strength of the existing and mod-ernized roller systems is calculated (Fig. 7), taking

6

With the participation of N.A. Evdokimov, S.E.

Gusev (OOOUralmash Engineering), S.A. Makurov, V.E. Fedotov, G.V. By-kov, and L. M. Mart’yanov (OAO VIZ-Stal).

account of the load when rolling strip of different widthand the existing profiling of the supporting and workingrollers. Finally, a design is developed for a special rollersystem that satisfies the strength requirements.

(a) (b)

YXZ

X

Z

MX

MN

MX

MN

Fig. 3.

Stress in blade (a) and yoke (b) of spindle hinge.

Y X

Z

YX

Z

Nut of adjusting screw

Adjusting screw

Frame

Lower part of pad

Tray

Supporting plate

Housing

2

1

Fig. 4.

Housing of Kvarto-2800 cell at OAO Severstal andadjacent parts taken into account in strength calculation.

YX

Z

MX

YX

Z

a

b

c

d

e

f

Fig. 5.

Calculation scheme and stress in the frame of the 900cell at OAO NTMK: (a) nut; (b) screw; (c) symmetry at thesurface in the

ZOY

plane; (d, e) rolling pressure distributed,respectively, over the cross section of the screw (b) and thesupporting plate (f).

NVNV(a) (b)

Fig. 6.

Stress in existing (a) and special (b) rollers of theKvarto-800 mill at OAO Shchelkovskii MetallurgicheskiiZavod.

YX

Z

P

A

Supporting roller

Working roller

a

b

a

b

Fig. 7.

Calculation scheme of the roller system for theKvarto-1300 mill (OAO VIZ-Stal): (a) roller pad; (b) rollerbearing;

P

, strip pressure in rolling;

A

, absence of verticaldisplacement at a point on the axis of the adjustment screw.

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CONCLUSIONSA methodology has been developed at Uralmash

Engineering for calculation of the load and strength andestimation of the working life of rolling-mill cells,using original software for calculating the energyparameters of hot and cold rolling, ANSYS software forcalculating the bulk stress–strain state, and familiarmethods for calculating the durability. Examples ofsuch calculations for existing mills indicate the possi-bility of estimating the minimum reconstructionrequired in order to introduce new products and toincrease the load and productivity of the mill.

REFERENCES

1. Makarov, Yu.D., Nedorezov, I.V., Beloglazov, E.G.,et

al., Development and Introduction of the Hot Sheet-Rolling Mill Program,

Metallurg

, 2007, no. 3, pp. 66–67.2. Khimich, G.L. and Tsalyuk, M.B.,

Optimizatsiya rezhi-mov kholodnoi prokatki na ETsVM

(Computer Optimiza-tion of Cold Rolling), Moscow: Metallurgiya, 1973.

3. Volegov, I.V., Nedorezov, I.V., and Nesterova, N.D.,Some Results of ANSYS Calculations in the Design ofOMZ Rolling Equipment and Presses,

Trudy III konf.pol’zovatelei programmnogo obespecheniya CAD-FEM

GmbH

(Proc. III Conf. of CAD-FEM Software Users),Moscow: Poligon-Press, 2003, pp. 340–346.

4. Volegov, I.V., Nedorezov, I.V., and Nesterova, N.D.,Some Results of ANSYS Calculations in the Design ofCold-Rolling Equipment,

Materialy IV mezhdunar.nauch.-tekhn. konf. Informatsionnye tekhnologii v proiz-vodstvennykh, sotsial’nykh i ekonomicheskikh protses-sakh (Infotekh-2004)

(Proceedings of Infotekh-2004: IVIntern. Conf. on Information Technology in Production,Social, and Economic Processes), Cherepovets: GOUVPO ChGU, 2005, pp. 87–89.

5. Volegov, I.V. and Nesterova, N.D., Stress–Strain State ofLoading and Unloading Equipment in Cold-RollingMills,

Trudy konferentsii i seminarov Nedelya metallov vMoskve

(Proceedings of Moscow Metal Week Confer-ences and Seminars), Moscow, 2005, pp. 269–271.

6. Kogaev, V.P., Makhutin, N.A., and Gusenkov, A.P.,

Raschety detalei mashin i konstruktsii na prochnost’ idolgovechnost’: spravochnik

(Calculating the Strengthand Life of Machine Parts and Structures: A Handbook),Moscow: Mashinostroenie, 1985.

7. Serensen, S.V., Kogaev, V.P., and Shneiderovich, R.M.,

Nesushchaya sposobnost’ i raschety detalei mashin naprochnost’: sprav. posobie

(Carrying Capacity andStrength Calculations of Machine Parts: A Handbook),Moscow: Mashinostroenie, 1975.