Pipe-rolling Mill Research Articles

Development of a Mechatronic System for the Main Drive of a Cold Pipe Rolling Mill

Development of a Mechatronic System for the Main Drive of a Cold Pipe Rolling Mill

Implementation of the calculation and analytical method for rationing metal consumption in the production of seamless hot-formed pipes at JSC TAGMET

This article discusses the issues of the correlation of theoretical provisions on the sphere of metal use planning and the practical implementation of scientific principles in direct economic practice. Existing rationing methods are analyzed in detail, the most advanced of them, the calculation and analytical method, is identified. It is indicated that this method is implemented only with the help of mathematical modeling. The basis for evaluating the issues of practical implementation is a case study on the development of JSC "Russian Research Institute of the Pipe Industry" tools with a high level of automation and allowing JSC "Taganrog Metallurgical Plant" to solve the problem of scientifically and technically justified calculation of the planned metal consumption in the production of pipe metal products at a pipe rolling mill. Premium Quality Finishing (PQF) continuous mill. The normative and instructive documents regulating this type of activity are given. The process of creating tools for standardizing metal consumption in the form of software products, common to all such works, is characterized. The non-stationary requirements for the process of creating tools, caused by the conditions of TAGMET JSC, are characterized. The emphasis in the material is on describing the features of the accounting policy, its changes, PJSC "Pipe Metallurgical Company" and JSC "Taganrog Metallurgical Plant" in the field of metal consumption rationing, through the chronology of the implementation of these features in software and methodological support. The dynamics of the process of introducing tools into the practice of the plant's specialists and the influence of subjective and objective factors on this process is traced. The results obtained from the implementation, which are an improved process of normalization, are reflected. It also indicates the progressive influence of the optimization of one process on the "adjacent" elements of the management structure.

Integrated Study of Transformation Mechanisms of Surface Defects during Rolling of Pipes in TPA-140 Pipe Rolling Mill

Integrated Study of Transformation Mechanisms of Surface Defects during Rolling of Pipes in TPA-140 Pipe Rolling Mill

Effect of Preliminary Deformation of Continuously Cast Billets by Radial-Shear Rolling on the Structure and Properties of Hot-Rolled Chromium-Containing Steel Pipes

The paper analyzes the effect of preliminary deformation of continuously cast billets (CCB) made of chromium-containing grades of steel by radial-shear rolling (RDR) on the structure and properties of seamless pipes. A bar stock measuring 105 mm in diameter was obtained using an RDR mill at large feed angles (β = 21°). A comparative analysis of the microstructure of the initial CCB and hotrolled bars has shown that radial-shear rolling enables intensive refinement of the structure of continuously cast billets, and ensures a high-quality (70 to 90%) work-up of the cast structure at reduction ratios of 2.0 to 2.2. A pipe-rolling mill (PRM) installed at the Pervoural’sk New Pipe Plant JSC (PNPP JSC) was used to obtain seamless pipes from the deformed bars, and the mechanical properties of such pipes were studied. It was found that the pipes obtained from the experimental billets are fully compliant with the ISO 11960:2004 requirements for strength group J55 (σt > 517 MPa; σ0.2 > 379 MPa; δ > 16%). In addition, the level of plastic properties of the experimental pipes (based on present elongation δ5, %) exceeds the ISO 11960:2004 requirements by 1.6–1.8 times. To achieve a comparable level of properties using the existing technology, an additional heat treatment (HT) is required, which points to the potential advantages of using RDR pre-deformed billets to obtain seamless pipes with the required properties.

Development of radial-shear rolling mill special stands for continuous cast billets deformation

The article offers the structure of the three-roll stand for radial-shear rolling that is designed to deformation of continuous cast billets. The stand can be installed in the pipe rolling mill manufacturing line that shall ensure manufacturing flexibility. To achieve the objective set, elaboration of working rolls integration with the drive as well as verification against the allowable torque and strength calculations in SolidWorks Simulation were performed at the design stage. For the major part of the frame, stresses do not exceed 60 MPa and the design rigidity rate will be 2.86 MN/mm. The special stand has a specific frame structure to ensure its mounting on the existing equipment base. The configuration of rolls sets is selected considering the possibility of integration with the spindle assemblies of the group drive and maximum allowable cross angle (≤ 15°). The developed design proves to have sufficient strength margin with the relatively small weight. The special radial-shear rolling mill stand will allow increasing total strain degree and reducing the number of billets sizes.

ЗАБЕЗПЕЧЕННЯ НАДІЙНОСТІ СТАНИНИ РОБОЧОЇ КЛІТІ ПРОШИВНОГО СТАНУ ТПА 350 ПІСЛЯ ЇЇ ДОВГОТРИВАЛОЇ ЕКСПЛУАТАЦІЇ

Мета. Дослідження напружено-деформованого стану станини робочої кліті прошивного стану трубопрокатного агрегату 350 (ТПА 350). Розробка методики визначення надійності станини робочої кліті прошивного стану ТПА 350 після її довготривалої експлуатації. Розробка стратегії подальшої експлуатації прошивного стану ТПА 350.Методика. При виконанні роботи проводилися тензометрічні виміри напружень, що виникають у станині прошивних станів ТПА 350, проводилися дослідження 3D моделі станини. Було розроблено математичні моделі для визначення функції розподілу довговічності станини прошивного стану та показника безпеки, а також для визначення довговічності станини при наявності існуючих дефектів.Результати. Наведено результати досліджень 3D моделі станин прошивного стану ТПА 350. Визначено напружено-деформований стан робочої кліті прошивного стану ТПА 350. Встановлено, що в станиніробочої кліті прошивного стану виникають максимальні напруження в зонах виявлених раніше тріщин, місця концентрації максимальних напружень «мігрують» при зміні умов закріплення станіни. Виявлено, що небезпеку представляють дефекти (тріщини), які з’являються в напружених зонах станини робочої кліті. Виявлено, що початкові розміри дефектів малі для надійного діагностування, але їх критичні розміри достатньо великі, щоб їх не виявити при обстеженнях. Встановлено, що безпека станини прошивного стану при більш жорстких умовах експлуатації, які фактично спостерігаються у реальності, була вичерпана після 75 років експлуатації. Дослідженнями напружено-деформованого стану встановлено, що зазори в місці з'єднання кришки й станини робочої кліті сприяють росту локальних напружень, наслідки появи яких аналізувалися в даній роботі. Наукова новизна. Вперше проведено дослідження надійності станини прошивного стану ТПА 350 після 80 років експлуатації. При розробці математичної моделі опору втомному руйнуванню використано І та ІІ моди руйнування. Практична цінність. Розрахунки показують, що в даний момент станина прошивного стану працює в зоні повного ризику, що супроводжується утворенням тріщин. Період живучості сферичного дефекту становить близько 5 років, після цього дефект трансформується в тріщину з погано визначною геометрією й розвивається по закономірностях, що вимагають окремого вивчення. Показано, що найбільш ефективно в цьому плані здійснювати її контроль неруйнуючими діагностичними методами. Для продовження експлуатації станини прошивного стану пропонується: надійно закріпити верхню кришку станини прошивного стану гвинтовим механізмом фіксації. Запропоновано максимально знизити (виключити) кількість труб, що виготовляються, із сплавів, що важко деформуються, робити діагностування кліті й регулярно перевіряти розміри тріщин.

New Approaches to Designing of Electrical Machines for Modern Controlled AC Electric Drives

In this paper, we consider new possibilities realized in alternating current electric machines that are designed for controlled electric drives and powered by semiconductor frequency converters. We concentrate on the possibility of improving the technical and economic performance of the system by taking into account the combined work of the semiconductor converter and the engine under development. The design of asynchronous electric machines for a semiconductor converter is shown to allow significantly improve its energy performance and expand the control range in terms of electromagnetic moment. The possibility of improving the mass–dimension parameters of synchronous machines operating in frequency-controlled systems is substantiated. We show that it is possible for these machines to exclude completely loss from synchronism. We established that synchronous reluctance machines can have specific indices close to those of asynchronous motors, and they realize a significantly larger overload torque in this case. Calculated methods for the synthesis of asynchronous electric drives that were successfully tested in the development of a series of main drives of the D423 drilling rig are proposed. These electric machines were designed for mechanisms with a fanlike load (mud pump) and with an active reluctance torque (winch drive). A synthesis method for the SRMTD synchronous reluctance engines that were tested on an engine for a cold pipe rolling mill is developed.

Algorithms and Control Systems for Electric Drives of Cold Pipe-Rolling Mills

The electric drive of a cold pipe-rolling mill operates at a low speed with great accelerations and overloads. This mode of operation dictates increased requirements for the speed and controllability. The integration of synchronous reluctance machines (SRMs) into controlled electric drives improves the productivity of the mill and the quality of products and energy performance due to good controllability, high overload capacity, absence of losses in the rotor, and low inertia of the former. The choice of algorithms and control structures significantly affects the characteristics of the electric drive. Control structures of an independently excited electric drive are considered. Pulse-width control of a voltage inverter by forming current diagrams using a spatial vector in a rotating d–q coordinate system and direct torque control (DTC) are considered as algorithms for controlling the electric converter. Taking into account the operating modes of the electric drive and the requirements imposed on it, criteria have been formulated for comparing control systems—namely, speed of the current, flux, and torque control circuits—and losses in the electric converter are estimated by the switching frequency of the power switches. According to the results of experimental studies using mathematical models, both control systems showed similar performance capabilities. It has been shown that, in DTC systems, the switching frequency of the switches and the associated losses of the semiconductor converter decrease in the torque overload zone.

Sludge conditioning after pipe-rolling mill aggressive sewage waters neutralization

Sludge conditioning after pipe-rolling mill aggressive sewage waters neutralization

VIBRATION PIERCING OF PIPE BILLET ON THE PIERCING PRESS OF PIPE-ROLLING MILL

The issues of using highly efficient technologies in the production of pipes on the piercing press of a pipe press installation are considered. The existing basic and perspective directions of intensification of deformation modes in the processes of metal forming using active controlled high-frequency vibrations are analyzed. It was established that, due to insufficient study, vibration processes do not find wide application in the production of seamless pipes. By analyzing and synthesizing a number of known fundamental studies, it has been shown that favorable conditions for metal deformation can be achieved by using high-frequency vibrations. It was revealed that the operation of the pipe billet piercing on the piercing press is accompanied by considerable losses to overcome the forces of technological resistance, characteristic for the process of deformations unevenness throughout the volume of the processed metal. Some previously unknown phenomena that arise during the implementation of existing technologies for pipe billets piercing have been established, which required the creation of new mathematical models of such processes that adequately reflect the conditions of the process of piercing or expanding the billets on modern piercing presses. A mathematical model of the dynamic wave processes arising in the processed metal is made. For the quasistationary process of pipe billet piercing differential equations of wave formation are obtained at the corresponding boundaries of the zones of the deformation center, characteristic for the plastic zone and the zone with cracking in the pierced metal. The parameters of the wave propagation boundary in the pierced pipe billet on the conjugate fronts of the plastic zone with the zone of crack formation are determined. It was established that deformations and stresses in the pierced metal depend on the rate of expansion of characteristic waves at the interface of contact with technological tools. A highly effective innovative technology of vibration piercing of a pipe billet on a piercing press of a pipe-rolling mill is substantiated. The features of realizing the technology of active controlled vibration piercing of the pipe billet on the piercing press of a pipe-rolling mill are determined. It is shown that the use of high-frequency oscillations on the press contributes to a significant increase in the efficiency of the technological process of piercing or expansion of pipe billets. The choice of rational parameters of high-frequency vibrators (amplitude-frequency characteristics), built into the system, resulted in a noticeable decrease in the energy-strength parameters du­ ring the piercing of the pipe billet and a significant improvement in the quality of the produced sleeves.

Pipe rolling on a short mandrel with kinematic tension

Improvement in pipe production on a longitudinal rolling mill is proposed. The tandem longitudinal pipe rolling mill in the pipe-mill aggregate (PMA)-140 at PJSC (public joint-stock company) Sinarsky Pipe Works is considered. Currently, pipe is produced both from rolled billet (diameter 120 mm) and from continuous-cast billet. To reduce costs, it would make sense to discontinue the use of rolled billet and to produce all of the pipe from continuous-cast billet in the existing PMA-140. In order to employ continuous-cast billet, more profound reduction in the tandem mill is necessary. At present, the reduction is 1.16–1.5 in longitudinal rolling mill 1 and 1.07–1.15 in longitudinal rolling mill 2. With greater reduction, longitudinal guide marks may appear on the pipe surface. A possible approach to decreasing the pipe wall thickening in the groove taper and hence reducing the rejection rate due to longitudinal guide marks is to employ kinematic tension in rolling an oval sleeve on a short mandrel. The influence of the kinematic tension on the pipe shaping in grooves during longitudinal rolling of an oval sleeve is investigated. This method is found to diminish the thickening of the sleeve wall in the groove taper in longitudinal rolling mill 1. That lowers the likelihood of longitudinal guide marks on the pipe’s internal surface. The possibility of increasing the reduction in rolling on an automatic tandem mill is confirmed.

Dynamics of a rod system restraining the mandrel in an automatic pipe-rolling mill

The dynamics of the system consisting of a sleeve (pipe), a mandrel, and a rod in an automatic pipe-rolling mill is considered. The Bessel equation provides the basis for a differential equation describing the motion of the mandrel rod, in which the time dependence of the system’s mass is taken into account. The operation of the rod system restraining the mandrel in the automatic mill is analyzed. The vibrational activity is studied, with allowance for the change in mass of the system.

Finite Element Analysis of Main Stand of Ф140 Pipe Rolling Mill and Split Casting

By using finite element software, the paper establishes the main stand analysis model of the Ф140 pipe rolling mill and provides the model analysis of main stand in cases of full load. Verify the design of main stand fully comply with the technical requirements .In this paper, it provides the theoretical position of split casting and welding method using electric slag welding.

Output Feedback H-infinity Control Design for Synchronizing of the Main Drives of the Pipe-Rolling Mill

We formulate the discrete-time output feedback controller design problem where the desired accuracy of controlled variables in the mean-square sense is guaranteed in the presence of bounded polyharmonic disturbances with a priori unknown number of harmonics, amplitudes, and frequencies. The amplitudes of the harmonics must satisfy a condition that results in the boundedness of the power of each polyharmonic component. The solution is based on the discrete-time H∞-optimization procedure by properly choosing the corresponding weighting matrices of the minimax cost criterion. Numerical solution in state-space is based on the method of linear matrix inequalities, using the LMI Control Toolbox (MATLAB application). We give the numerical example for the main drives pipe-rolling mill where the digital controller is synthesized using the LMI Control Toolbox package.

Dynamics of drive line in helical pipe-rolling mill

Experiments on helical pipe-rolling mills provide information regarding the functioning of the drive line. Means of addressing the dynamic behavior of the primary drive and the nonuniform roller motion are proposed. Rational hinge parameters in the universal drive spindles permit minimum amplitude of the working-roller vibration.

Digital regulator for synchronizing the primary drives in a pipe-rolling mill

Digital regulator for synchronizing the primary drives in a pipe-rolling mill

Synthesis of an automatic controller for a multidrive pipe-rolling mill

In the present work, output controllers are designed for a multidrive pipe-rolling mill. Besides the specified radius corresponding to the reserves of stability at the physical output, these controllers ensure the specified steady-state radius, characterizing the operational precision of the closed system with respect to the controlled variables. It is shown that this problem reduces to a special H ∞ -optimization problem, and the result is adequate. Numerical solution in state space is based on the method of linear matrix inequalities, using the LMI Control Toolbox option in MATLAB software.

Time-resolved spectral method of magnetic-induction flaw detection of pipes in real time

A technique for nondestructive testing of pipes based on visualization of frequency characteristics of segmented detector signals is presented. Most of the information is conveyed by the low-frequency band of the spectrum. Experimental tests of the technique on a pipe rolling mill are described.

Metrological provisions for production at the K. Liebknecht pipe rolling mill

Metrological provisions for production at the K. Liebknecht pipe rolling mill

A carousel-type furnace in a pipe-rolling mill

A carousel-type furnace in a pipe-rolling mill