Theory and Practice of Resource-Saving Technologies of Mill Bar Production at the Operating Continuous Rolling Mills

Bazaikin

Belyaev

et al. 2020

A promising direction for production of simple profiles by rolling includes grooveless rolling. Due to the use of forming in smooth rolls, this direction significantly reduces the production cost of finished products and simplifies the rolling process. However, despite all the obvious advantages of deformation in smooth rolls, there are disadvantages that complicate industrial implementation including the need for edging after each pass and a small coefficient of extraction in smooth rolls. It causes an increase in the number of passes. For the solution of problems encountered in current industrial implementation of grooveless rolling, it is proposed to use deprived-wide vertical stands in continuous groups. Deformation in non-water vertical stands is provided by more complete use of the reserve of contact friction forces of the drive stands installed in front of them. The conditions under which the use of non-water vertical stands is possible are determined. After solving the equation of forces equilibrium on the contact surface in the deformation center of the drive stand, dependence is obtained by which it is possible to find the value of longitudinal force provided by reserve of friction forces. By solving the equation of power balance in form of non-drive rolls, the dependence is obtained determining the longitudinal force required for deformation. The authors offer the dependence by which it is possible to determine the maximum allowed distance between the drive and non-drive stands, providing longitudinal stability of the strip. Using dependencies to determine conditions of deformation in horizontal drive and non-driven vertical mills with smooth rolls, reduction modes during rolling of rebar No. 12 in conditions of JSC “EVRAZ ZSMK” 250 continuous light section mill using roughing stands for grooveless rolling were calculated. As a result it was found that the use of non-water vertical stands allows rolling of larger cast billet of 125x125 mm square on the mill. Economic component of transition to the larger cast billet with development of grooveless rolling was estimated. Advantages of the proposed solutions are shown in comparison with classical method of rebar No. 12 rolling on 250 continuous small-grade mill of JSC “EVRAZ ZSMK”.

Section: Doi: 1017073/0368-0797-2019-12-918-924unclassified

Innovative technology for production of rolled profiles with simple form

Bazaikin

Belyaev

et al. 2020

Features of the rolling-separation technology development on operating continuous small-grade mill

Никитин

Belyaev

et al. 2020

Аt present, there is a steady tendency to increase volume of i dustrial and civil construction in Russia and abroad. This in turn makes it necessary to enhance production of structural sections and in particular – reinforcing bar. One of the promising ways to increase production of reinforcing bar at existing rolling mills is development of rollingseparation technology. This technology provides growth in productivity of existing small-grade mills and reduces energy costs without large capital expenditures. However, despite its apparent simplicity, introduction of rolling-separation technology at existing enterprises causes difficulties associated with insufficient coverage of this experience in literature. The article presents experience of introduction of the rolling-separation technology on operating continuous small-grade mill. The research was carried out on equipment available in the workshop and used to monitor load of the main engines. Features of energy costs distribution on stands were studied at classical rolling and with the use of technology of rolling-separation of reinforcing bar No. 10, No. 14 made of 35GS and 3PS steel. Experimental graphs of the main engines of the rolling mill load show redistribution of energy consumption in stands for roughing, intermediate and finishing groups when using rolling-separation technology. Data on application of the main engine power and distribution of the specific load on the stands in classical rolling method and using rolling-separation technology are presented in graphic form. Analysis of the received data allowed us to reveal features of energy consumption at development of rolling-separation technology during operation. It is shown that use of this technology leads to additional load on stands of finishing groups. Energy savings during introduction of rolling-separation technology were quantified, and it was found that with a decrease of the rebar number, efficiency increases. Reduction of energy consumption during development of this technology in current production is associated with a decrease in machine time.

Capabilities of grooves forming articulated profiles for rolling – separation technology

Vakhrolomeev

Никитин

2022

The emerging growth of industrial and civil construction in Russia and introduction of new technologies have caused the need to increase the production of construction rolled products and, especially, rebar. One of the ways to increase rebar production at existing mills in the shortest possible time without serious capital investments is the use of rolling – separation technology. For successful implementation of this technology, the conditions for the feasibility of this process are given in this report. New dependences were obtained for determining the longitudinal force provided by the reserve of friction forces during formation of an articulated profile taking into account the profile shape and the conditions of shape change.