Search

The influence of the scale factor of the deformation zone, which is understood here as the ratio of the cross-sectional areas of the billet and roll, on the rolling speed and force conditions is analytically modeled using the slip-line technique. For the rolls under consideration, the existence of an optimal scale factor of the deformation zone is revealed, which ensures the most effective action on the macrostructure of the deformed billet. In terms of the force and speed conditions of the development of metal shear displacements during rolling, the effect is achieved by increasing the locally deformed volume of material by the rolls. [ABSTRACT FROM AUTHOR] more...

The results of a study of the influence of parameters of the temper rolling process of hot-rolled strips under the conditions of continuous pickling unit no. 4 of PJSC Severstal with an assessment of the formation of their surface roughness are presented. Patterns of changes in strip roughness during temper rolling were obtained depending on the mileage of work rolls prepared using electrical erosion texturing. Based on an assessment of the stressed state of the metal in the deformation zone, the patterns of influence of the parameters of the temper rolling process of hot-rolled pickled strips on the degree of transfer of roll roughness to the surface of the strip are determined. Recommendations for choosing rational tempering regimes are given. [ABSTRACT FROM AUTHOR] more...

Abstract—Two technological processes of electroslag cladding onto rolls in a current-carrying mold are considered. It is shown that when cladding with a discrete material, both manufacturing and reductive cladding can be performed with the use of any method for relative motion of the mold and the roll under cladding. The lectroslag cladding with the use of liquid metal is carried out according to a pattern for extracting the roll under cladding from a permanently fixed mold. Technological equipment used for both cladding processes is presented. It is noted that the equipment is similar for these processes with the exception of dosing units. [ABSTRACT FROM AUTHOR] more...

Formation mechanisms of the stress-strain state (SSS) of rolls of the cold-rolled strips during heating, isothermal tempering and cooling during annealing in bell furnaces have been studied. Detailed analysis of the influence of annealing temperature ramping conditions on the appearance of critical inter-windings pressures in the rolls resulting in the strips surface "kinks" ("breaks") and other types of defects have been provided. Shown here are the possibilities of influencing the roll' SSS during annealing by controlling the duration of isothermal exposure and the rate of subsequent roll cooling under the furnace muffle. Thus, the influence of the cold rolling on the rolls' SSS is considered as well. Optimized temperature ramps regimes are recommended for the thin strips' roll annealing in the production of the cold-rolled steel intended for highly complex stretching, providing prevention of adhesion-welding of the adjacent windings of the rolls and delivering high quality finished products. [ABSTRACT FROM AUTHOR] more...

The formative patterns of gaps between turns of cold-rolled strips in rolls and the ways these gaps affect the stress-and-strain state (SSS) of these rolls are disclosed. The effects of surface roughness, temperature, physical mechanical properties, strain degree, and hardening of cold-rolled steel on the interturn gaps in and the roll's SSS are analyzed in detail. Possibilities of affecting the roll's SSS by adjusting the cold-rolling temperature of fine strips and tinplate are exposed. Recommendations on choosing thermal-speed modes of strip rolling and coiling are presented. [ABSTRACT FROM AUTHOR] more...

For the production of high-strength reinforcing bars with a diameter of 9.5 mm from C86D steel, cold-formed rebar with a diameter of 9.7 mm was used, made according to the direct drawing scheme from hot-rolled coiled steel with a diameter of 16.0 mm, which was subjected to cold profiling with a dent depth of 0.20 mm in an idle three-roller stand and subsequent stabilization at a temperature of 390 ± 10°C with a specific technological tension of 480 MPa. The power parameters of the application of a periodic profile on the conversion workpiece, the maximum value of the forces acting on the rollers, as well as the values of the required pulling force, have been determined. It has been experimentally shown that a 5.0% decrease in the idle cross-section of a reinforcing bar after deposition of indentations and stabilization is compensated by an increase in σu and σ0.2 by 4.6 and 8.7%, respectively. It has been shown that correction of roll adjustment is necessary during the line riding period and development of process tension. The proposed methodological approach with the use of modeling makes it possible to design equipment for the profiling of rebar integrated into the line of the stabilization section with a pulling device. [ABSTRACT FROM AUTHOR] more...