Browsing by Author "Mazur I."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Development and theoretical study of new scheme of realization of combined process ``rolling - pressing`` using equal channel step matrix(2017-01-01) Naizabekov A.; Lezhnev S.; Panin E.; Koinov T.; Mazur I.Using a computer simulation it was conducted a study of new modification of the combined process ``rolling-pressing``, the distinctive feature of which is the use at the exit of equal-channel step matrix vertical rolls instead of horizontal rolls. It was performed the investigation on the stress-strain state, the deformation of the workpiece and the microstructure evolution. The values obtained were compared with those of the model with two pairs of horizontal rolls. As a result, it was found that the use of vertical rolls at the exit of the equal-channel step matrix has the following advantages: the treatment of the workpiece is more uniformly throughout the section; in general, by changing the direction of compression during rolling in the vertical rolls the deformation occurs at much lower values of the extrusion, which entails a slight change in the original dimensions of the workpiece; the initial grain size is reduced more intensively both on the surface and in the central zone.Item Evaluation of the effectiveness of the use of horizontal and vertical rolls in the ``rolling-pressing`` process on the basis of the stress-strain state studying(2017-03-01) Lezhnev S.; Naizabekov A.; Panin E.; Koinov T.; Mazur I.; Arbuz A.In this work was performed a comparative analysis of the efficiency of horizontal and vertical rolls in the ``rolling-pressing`` process. The comparison was performed based on the study of stress-strain state of both variants with the aid of computer simulation in the program DEFORM-3D based on the finite element method. For analysis of the stress state was used the Lode-Nadai coefficient, allowing you to determine which type of deformation is realized at a specific point - tension, compression or shear. For analysis of the strain state was used equivalent strain, which allows to estimate the common level of accumulated strain. In the comparative analysis of parameters of SSS was revealed that the use of vertical rolls at the exit from the matrix during ``rolling-pressing`` process, allows you to achieve a more favorable distribution of deformation along the entire length of the deformable workpiece.Item Improvement of the technology of working S-shaped rolls grinding in hot condition(2015-01-01) Astakhov A.; Jordanova R.; Mazur I.The paper discusses the way to improve the methodology of S-shaped working rolls grinding by taking into account its thermal deformations, which appear during the campaign by the contact with hot strips. An algorithm of working rolls grinding in hot condition is developed by using the mathematical model of the thermal expansion, which allows one to predict changes of the profile of S-shaped rolls. The algorithm and the results of its manufacturing approbation are presented in this paper.Item Influence of the transversal displacements of metal on the camber formation of hot-rolled strip(2017-01-01) Belskiy S.; Yankova S.; Mazur I.; Stoyakin A.Transversal displacements of metal in the hearth of deformation reduce unevenness of elongations across strip width, wherein the camber curvature becomes smaller, and its radius is larger than that calculated on the assumption of plane deformation scheme. The investigations are based on the variational principle of possible changes of strain state (Jourdain principle). It is assumed that the input velocity unevenness of the metal flow in the hearth of deformation across the strip width passes into an output one proportionally to reductions. Further, velocities and powers of deformation and displacements of metal in the hearth of deformation during hot rolling and corresponding powers are calculated. Solving Euler-Poisson's equation, we receive the expression for coefficients, which take into account the influence of the transversal displacements of metal on decreasing the output unevenness and the radius of camber curvature for every harmonic.Item Quality control system for a hot-rolled metal surface(2016-06-01) Mazur I.; Koinov T.The modern ideas about of quality of products are based on the principle of the absolute satisfaction of requirements of recommendations of the buyer. A presence of surface defects of steel-smelting and rolling origin is peculiar to the production of hot-rolling mill. The automatic surface inspection system (ASIS) includes two digital line video cameras for the filming of the upper and lower surfaces of the flat bar, block of illumination of the upper and lower surfaces of the flat bar, computer equipment. A system that secures 100 % control of the surface of rolled metal (of the upper and lower side) detects automatically and classifies the sheet defects in the real time mode was mounted in the domestic practice in the first time in 2003 on hot rolling mill 2000 JSC «Novolipetsk Iron & Steel Corporation» (NISC). The whole assortment of the mill 2000 was divided for the five groups by the outward appearance of the surface. The works on the identification of defects of hot-rolled metal and widening of data base of knowledge of ASIS were continued after the carrying out of guarantee tests. More than 10 thousand images of defects were added to the data base during the year.Item Quality control system for a hot-rolled metal surface(2014-02-25) Mazur I.; Koinov T.The modern ideas for the quality of products are based on the principle of the absolute satisfaction of buyer,s requirements and recommendations. A presence of surface defects of steel-smelting and rolling origin is peculiar to the production of hot-rolling mill. The automatic surface inspection system (ASIS) includes two digital line video cameras for the filming of the upper and lower surfaces of the flat bar, block of illumination of the upper and lower surfaces of the flat bar, computer equipment. A system that secures 100 % control of the surface of rolled metal (of the upper and lower side) detects automatically and classifies the sheet defects in the real time mode was mounted in the domestic practice in the first time in 2003 on hot rolling mill 2000 JSC «Novolipetsk Iron & Steel Corporation» (NISC). The whole assortment of the mill 2000 was divided for the five groups by the outward appearance of the surface. The works on the identification of defects of hot-rolled metal and widening of data base of knowledge of ASIS were continued after the carrying out of guarantee tests. More than 10 thousand images of defects were added to the data base during the year.Item Research and development of technology for rolling of high-quality plates of non-ferrous metals and alloys in relief rolls(2016-01-01) Naizabekov A.; Lezhnev S.; Koinov T.; Mazur I.; Panin E.Studies on deformation of a plate workpiece in rolls with a surface relief in the form of annular grooves forming a trapezoidal ledges and cavities alternating each other along the entire length of the barrel (the first pair with unequal ratio of the ledge to the cavity and the second pair with equal ratio of the ledge to the cavity) have been carried out. Computer simulation of the rolling process in the rolls with unequal and equal treatment of the ledge to the depression showed the advantage of the first scheme, because in this case is implemented pure shear without compression, which is beneficial to the uniformity of distribution of accumulated plastic deformation, which, in turn, affects the forming of the workpiece. Laboratory studies have confirmed the simulation results. The analysis of the intensity of shear strain proved the superiority of the first scheme and the analysis of rolling load showed the advantage of using the relief rolls instead of smooth.