Avtomaticheskaya Svarka (Automatic Welding), #3, 2021, pp. 35-39
Improvement of the surfacing technology for large backup rolls of hot rolling mills
L.K. Leshchinskiy, V.M. Matviyenko, V.P. Ivanov, K.K. Stepnov, E.I. Vozyanov
Azov State Technical University, 7 Universitetskaya Str., 87555, Mariupol, Ukraine. E-mail: email@example.com
It is shown that when surfacing large backup rolls of hot rolling mills made of 90CrV steel, the limited weldability of steel
leads to the need to select the thermal mode of surfacing that ensures the required operability of the deposited layer. The choice
of materials and technology of surfacing the transition zone from the base metal to the working layer determines appearance of
hardness dips and formation of a «soft sub-layer», which leads to occurrence of spallation. Elimination of such dips depends
on the choice of the deposition mode of each of the layers, in accordance with the composition and size of the electrodes used.
It is shown that application of a 1.0 mm thick strip electrode from 08kp, 30KhGSA, 25Kh5FMS steels for surfacing makes it
possible to obtain a smooth (without dips and bursts) change in hardness along the height of the multilayer composition, which
contributes to an increase in spalling resistance when the height of the deposited layer decreases during the operation of the roll.
The high efficiency of the surfaced backup rolls was confirmed during industrial development of the surfacing technology of
the rolls and their long-term operation in the hot rolling mill, The developed and implemented routing scheme for movement
of the deposited and new backup rolls (the share of deposited rolls reached 30%) in the roughing group of stands of mill 2000
of the Cherepovets Metallurgical Plant made it possible to ensure the operating time of surfaced rolls commensurate with that
of new rolls as to the tonnage of rolled products. 12 Ref., 4 Tabl., 2 Fig.
backup rolls, 90CrV steel, surfacing, underlayer, transition zone, composition of layers, hardness, spalling of the
surfaced layer, strip electrode, surfacing mode, hot rolling mill, roughing stand, roll route, operating time of surfaced rolls
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layer with the regulated distribution of properties. Mariupol,
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7. Leshchinskiy, L.K., Gulakov, S.V., Nosovskiy, B.I., Stepnov,
K.K. (1977) Causes of fracture of the deposited working layer
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8. Kostin, V.A. (2012) Mathematical formulation of carbon
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and mechanical properties of the reconditioned railway
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