Pipe Rolling Research Articles

Algorithm for optimization of cold‑rolled pipe rolling routes

The relevance of the work is justified by the need to refine the methodology for calculating cold rolling routes, associated with the expansion of factors that need to be taken into account in conducting such calculations. The aim of the work is to develop an algorithm for optimizing the routes of cold rolling of pipes using CRP and CRPR type mills, convenient for implementation in a software product. The paper analyzes the main parameters for optimizing the routes of cold rolling of pipes, factors limiting the field of optimal values of the geometric parameters of the billet‑pipe in each pass. Among the latter, the maximum possible reduction in the cross‑sectional area, the required reduction in the cross‑sectional area in the last pass, the requirement for the nature of the distribution of the reduction value in the cross‑sectional area, in the wall thickness and in the pipe diameter from pass to pass and other parameters are highlighted. The importance of minimizing the number of passes is noted. The main dependencies included in the method for calculating the deformation parameters of the cold rolling route using CRP and CRPR mills are analyzed and highlighted. An algorithm for calculating the route of cold rolling of pipes, with several iteration operations, has been developed. The proposed algorithm allows optimizing the rolling route of pipes made of any grades of steels and alloys, and allows optimizing most parameters, including those affecting the economic parameters of production. Depending on the grade of steel or alloy, some iteration operations can be excluded. The algorithm has been tested in the practice of calculating rolling routes for pipes made of carbon and stainless steels and alloys.

Параметры, влияющие на стоимость продукции металлургических и трубопрокатных производств в различных регионах РФ

The article considers the market of oil products, the prices of which directly affect the cost of production of the strategically important pipe rolling industry, by years and regions. The geography of metallurgical enterprises location on the territory of the Russian Federation and regional zones are analyzed. Generalized indicators of the Russian steel pipe market are structured by key indicators and federal districts depending on average consumer energy prices in the domestic market. The geographical factor that most strongly influences the final cost of power supply to pipe rolling enterprises-consumers in price zones was identified.

Development of the method for determining the plane cross-wall diversity of cold-rolled pipes on the basis of experimental research with different options of feeding and turning

In recent years, cold pipe rolling mills have been used in Ukraine, where it is possible to perform different modes of feeding and turning the pipe. Formulation of the problem. We need a method that makes it possible to plan the cross-wall variation of the pipes. Goal. Development of a method for determining the planned diversity for the design of production technology to ensure the regulated increased quality of pipes according to their geometry. Methodology. Obtaining experimental results on the effect of feeding and turning modes during cold rolling on the cross-wall variation of pipes. Mode 1 – the feed is performed before the forward movement, and the turn before the reverse movement of the cage; mode 2 - the feed is performed before the forward movement, and the turn is performed before the forward and reverse movement of the cage; mode 3 – feeding is performed in the front and back position of the cage, and the turn is in the back position; mode 4 – feeding and rotation are performed before the forward and reverse movement of the cage). The results. Of the tested modes, mode 2 and mode 4 are the most effective (from the point of view of correcting the cross-sectional variation of the pipe blanks. Scientific novelty. First, additional experimental data were obtained on the magnitude of the cross-sectional variation of the pipes during the cold rolling process of the pipes with different modes of feeding and turning in front of the straight and It is shown that the process of cold rolling of pipes with feed in front of the direct and turning before the direct and reverse movement of the cage gives 1.5 times better indicators in terms of tube accuracy compared to feeding in front of the direct movement of the cage and turning before the reverse movement of the cage. Тhe indicators are given by the process with forward and reverse motion of the cage. Practical significance. The obtained results are needed in the development of technologies for the production of pipes with increased requirements for transverse diversity

Installation of portals in the sections of the column demolition during the re-equipment of Tagmet JSC workshops

Introduction. The article presents the materials on the activities, carried out in the pipe rolling shops of the Tagmet JSC during the modernization period, starting from 2007. The Research Institute of Building Constructions named after V.A. Koucherenko, conducted prolonged surveys of plant workshop structures in order to issue conclusions on their industrial safety and recommendations for the repair and strengthening of damaged elements in building structures for their further safe operation, including workshops, where the technological process has been changed due to the installation of new equipment.Aim. To demonstrate one of the ways to reconstruct industrial buildings using the example of workshops, located in the territory of the Tagmet JSC, based on a survey of combined structures, calculations and analyzes of their bearing capacity margins.Materials. The article provides the drawings of original metal structures and photographs of steel structures, already built to reinforce them and change the existing parameters of the building frame to suitable ones for new operating conditions.Results. Recommendations for structural strengthening, applicable for similar activities, are given. Due to the scientific and technical support for the design and construction of three modernized Tagmet workshops, the plant continuously increased its productivity in subsequent years.Conclusions. No defects and damage, which exceed the values, established by the current regulatory documents, and affect the operational suitability of buildings, were revealed during the inspection and operational safety examination of Tagmet plant structures. The results of the calculations, performed to the portal structures at the column demolition sections of the plant workshop building frames, proved the assurance of their strength and stability. The design solutions were successfully implemented during the reconstruction of workshops at the Tagmet JSC.

A universal simulation model of the continuous pipe rolling process on a controllably movable mandrel.

To study the technological process of rolling solid and hollow round profiles, it is important to have a correct mathematical description of the patterns that determine the boundaries of the deformation zone. The article analyzed scientific works that examine the calculation of geometric parameters of the deformation zone during the rolling of solid and hollow round profiles in two-roll and multi-roll calibers. As a result of the analysis, a conclusion was drawn regarding the necessity of a more detailed description of the determination patterns for the geometric boundary conditions of the deformation zone. This led to the proposal of a universal method for determining the shape of the billet and the shape of the caliber groove, as well as the derivation of the equations for the roll surface and the boundary of the contact surface of the deformation zone for various rolling schemes. The developed method allows for an increase in the accuracy of calculating the energy-force parameters of the rolling processes, including continuous rolling, in the production of solid and hollow round profiles according to the circular–oval scheme in calibers formed by any number of rolls, thanks to the consideration of a sufficiently wide range of geometric features

Ways to improve the processes of longitudinal rolling on a pipe rolling plant with a plug mill to reduce metal consumption and increase production output

Ways to improve the processes of longitudinal rolling on a pipe rolling plant with a plug mill to reduce metal consumption and increase production output

ОСОБЛИВОСТІ МІКРОСТРУКТУРИ ОСЬОВИХ ЗАГОТОВОК ПІСЛЯ ПРОКАТУВАННЯ

A study of the features of the structure of axle blanks made of steel grade F (AAR M-101-2017 Axles, carbon steel, heat-treated) after longitudinal rolling on a TPA 5-12" pipe rolling unit with pilgrim mills in three crimping modes (1 mode: Ø 470 → Ø 380 → Ø 260 mm; 2nd mode: Ø 470 → Ø 420 → Ø 260 mm; 3rd mode: Ø 470 →Ø 260 mm). Determination of the features of the distribution of deformation work and the formation of the final structure after deformation according to the experimental modes of BLZ Ø470 mm per circle Ø260 mm is the goal of research. It was determined that the uniformity of the grain structure is the highest after the application of mode #3 (Ø 470 →Ø 260 mm).

ОБ ИСПОЛЬЗОВАНИИ ОТРАБОТАННЫХ ОПРАВОК ПРОКАТНОГО СТАНА ДЛЯ ИЗГОТОВЛЕНИЯ МАТРИЧНЫХ КОЛЕЦ ПРЕССОВЫХ ЛИНИЙ ТПЦ-2 В УСЛОВИЯХ АО «ВТЗ»

The possibility of using secondary raw materials from waste mandrels of the continuous TPA mill 159-426 mm of the pipe rolling shop TPP-3 in the manufacture of matrix rings (matrices) for the press lines of the pipe-pressing shop TPP-2 of VTZ «JSC» has been confirmed. The approach used allows us to reduce costs, and the development of the metal structure with subsequent heat treatment increases hardness and further increases the durability of pressing tools for pipe production.

Development of the Mathematical Model of Continuous Pipe Rolling and Study of the Influence of Technological Factors on the Formation of Surface Defects

Development of the Mathematical Model of Continuous Pipe Rolling and Study of the Influence of Technological Factors on the Formation of Surface Defects

Investigation of defect formation in the form of longitudinal folds at the ends of semi-finished pipes during rolling on an automatic TPA mill

The article presents an elimination method aimed at addressing the defects in the form of longitudinal folds at the ends of semi-finished pipes during rolling on automatic mills of a pipe rolling plant (TPA). Currently, this issue is relevant, as it significantly affects the quality of the pipes produced. The developed solution is based on the implementation of a special design that prevents the occurrence of longitudinal folds at the ends of semi-finished pipes. Experimental studies have been conducted to confirm the effectiveness of the proposed technical solution. The obtained results demonstrate a significant reduction in the number of defective pipes and an increase in the overall volume of high-quality production. The developed technical solution represents a significant contribution to the improvement of pipe rolling technology on automatic TPA mills and can be applied in production conditions to enhance outcomes and resource efficiency

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

Application of Nonlinear Static Analysis to Evaluate the Side Rack Load Parameters of a Train Car Platform for Pipe Transportation

The results of comparison of the methods of studying the parameters of embedding reliability for the side rack unit, which is one of the most critical units of the pipe transportation train car platform, are presented. We show the inaccuracy of the existing methodology for calculating the train car platform side rack loading parameters affecting the reliability and safety of freight transportation; we also propose a new calculation method applying nonlinear static analysis with account for the pipe rolling force.

Current level of development and improvement of the design process for tool calibrations of CRP mills

The article presents the results of review analysis of publications of Russian and foreign authors (representatives of both new and established research teams), considering the directions of improvement of existing processes of cold rolling of pipes (CRP). It is shown that for the last decades a major part of studies is devoted to solving different design problems, including the improvement of power elements of electric drive and drive mechanisms, improving of electromechanical system of feeding and turning mechanisms, development of delivery tables structural design, tooth rack, etc. Less attention is paid to finite-element modeling of cold rolling process at tube mills. Separately, the issue of designing of technological tool calibrations of CRP mills has been analyzed. Currently main scientific and technical activities aimed at improving the software and methodological apparatus for designing gauges are focused on specifying individual parameters of already developed earlier classic design procedures and their implementation in various proprietary software products. Examples of modern calculation algorithms, design schemes and main characteristics (advantages and disadvantages, influence on quality indexes of pipes) of current stage of rolling mills technological tools calibrating are given. The functional and technical features of the software products used for this purpose are analyses and the current requirements for modern software are given. Based on the analysis, it is shown that maximum concentration of previously achieved results and their synergy with modern world research trends in calculation methods development of tool profiling in CRP mill is a timely and strategically important task for the domestic pipe industry.

The Arms and Armour of the Bishopric of Winchester in the Thirteenth Century

This article examines the inventories of arms and armour stored at the castles of Taunton and Farnham that are recorded in the pipe rolls of the bishopric of Winchester in the thirteenth century. Relatively few inventories for this period survive, which means that these rolls provide unique insights into changes in military equipment in England. This includes providing information about the types of armaments used by footmen, crossbowmen, and knights, as well as technological developments such as the adoption of plate armour.

Microstructures and mechanical properties of cold rolled pipes with increased small deformation

Purpose. Experimental study on microstructure, mechanical properties of pipe diversity on a new type of cold rolling pipe, which has the ability to perform different modes of supply and rotation. Methodology. Research method is an experimental one on modern industrial equipment using modern devices. The study was conducted when rolling pipes made of steel 08Cr18Mn10Ti on the CRP 6-20 mills. Rolling route is often 25 × 2.5 mm ® 16 × 1.5 mm, which is often used in production. Rolling was carried out on the CRP 6-20 mills in four modes of feed and rotation: mode 1 – feed is performed before the forward stroke, and rotation before the return stroke of the stand; mode 2 – the feed is performed before the forward stroke, and the rotation before the forward and reverse stroke of the stand; mode 3 – feeding is performed in the front and rear position of the stand and rotation in the rear position of the stand; mode 4 – feed and turn are performed before the forward and reverse of the stand. Findings. Metallographic studies on microstructures showed that for mode 1, the grain size on the outer surface of the pipes is less than on the inner surface. The difference reaches the value of 1–2 points. For mode 4, the opposite is true. The size of the grains on the outer surface of the pipes is larger than on the inner surface. The difference reaches the value of 1–2 points. This can be explained by the fact that in mode 1 most of the compression is performed in the forward stroke rather than in reverse stroke. And in mode 4, these crimps are close in value and smaller than in a forward stroke in mode 2. Originality. New experimental industrial data have been obtained for the first time on the state-of-the-art cold rolling mill for small-diameter pipes made of microstructures of riveted steel 08Cr18Mn10Ti in cross-sectional and longitudinal sections of the pipes on the outer and inner surfaces of the pipes and between them for four possible feeding and turning modes. For the first time, experimental industrial data on the values of strength limit, yield strength and ultimate elongation at four feeding and turning modes have been obtained as well. Practical value. The obtained experimental industrial data from a set of quality parameters of pipes – metal microstructure, mechanical properties, transverse differences in pipe packages allow one to choose modes of supply and rotation in the production of cold-formed pipes to ensure compliance with regulated quality parameters of supply and rotation pipes.

Improvement of tool calibration in cold pilligrim rolling mill

In the manufacture of cold rolled tubes, the process performance of the rolling mill and the deformed metal is determined by tool calibration. The method of calibration calculation, the method and equipment of its reproduction significantly affect the deformability and quality of pipes, the cost of rolling tools, productivity, and in general the efficiency of cold (warm) rolling of pipes. Tool calibration is the distribution of individual compressions along the length of the working stroke of the rolls, determined by the shape and size of the grooves and the mandrel. The need to improve the calibration of rolling tools is determined by the ever-increasing requirements for pipe production products. In this article, it is proposed to set the function of relative reductions as a product of elementary functions. In the course of the work, the coefficients of the proposed function were determined from the condition of the minimum load on the gauge at the pre-calibration section to ensure the minimum longitudinal difference in the thickness of the pipes. Calibration and forces during rolling of stainless thin-walled pipes of size 95×2 mm by the improved method have been calculated using MS Excel. The force parameters of rolling, calculated using the improved method, are compared with the forces calculated using other well-known calibration calculation methods. It is shown that the proposed technique provides lower values of force on most of the crimping section, which allows reducing longitudinal variation of pipes and increasing durability of calibers. To assess the accuracy of rolled pipes, the calculation of the elastic deformation of the stand was carried out depending on the force in the pre-calibrating section. The calculated value shows that the proposed improved method of tool calibration allows rolling pipes of increased accuracy. The developed procedure involves the use of size 95×2 mm pipes made of 12X18H10T steel for rolling in order to produce from a two-pass scheme to a single-pass scheme while ensuring the required high cost of pipes.

Analysis of the transformation of the microstructure of axial billets after rolling

The task of improving the quality of metal products of large cross-sections pro-duced from continuous cast billets (CBS) is associated with a number of difficulties. These include the presence of internal defects in the macrostructure of the workpiece (axial looseness, porosity, liquation, crystallization cracks, etc.). Processing from the point of view of deformation of cast workpieces is necessary first of all to eliminate cast defects. An increase in working out contributes not only to the welding of existing mi-crodiscontinuities and, in this connection, to an increase in the density of the metal, but also to the extraction, crushing and reduction of the cross-section of the existing non-metallic inclusions. However, the dimensions of the elements of the primary structure, which are presented on the graphs, are also of the greatest importance. The smallest level of liquation is formed in the surface areas during crystallization. At the same time, as a rule, it is necessary to obtain a homogeneous structure in terms of grain size on the cross-section of large-sized metal products. A study of the features of the structure of axle blanks made of steel grade F (AAR M-101-2017 Axles, carbon steel, heat-treated) after longitudinal rolling on a TPA 5-12" pipe rolling unit with pilgrim mills in three crimping modes (1 mode: Ø 470 → Ø 380 → Ø 260 mm; 2nd mode: Ø 470 → Ø 420 → Ø 260 mm; 3rd mode: Ø 470 →Ø 260 mm). Determination of the features of the distri-bution of deformation work and the formation of the final structure after deformation according to the experimental modes of BLZ Ø470 mm per circle Ø260 mm is the pur-pose of the research. Samples for the structure study were taken both from the original BLZ and the finished draft axle along the entire cross-section. The greatest unevenness of the liquation background, which is observed in the axial blank manufactured using mode No. 1, is also manifested during the study of the microstructure of railway of the axes obtained by the indicated modes. It was determined that the uniformity of the grain structure is the highest after using mode No. 3 (Ø 470 →Ø 260 mm).

Peculiarities of Fatigue Crack Growth in Steel 17H1S after Long-Term Operations on a Gas Pipeline.

This work presents the results of metallographic studies and the tensile, impact, and fatigue crack growth (FCG) resistance tests of 17H1S main gas pipeline steel in the as-received (AR) state and after a long-term operation (LTO). A significant number of non-metallic inclusions forming chains stretched along the direction of pipe rolling were found in the microstructure of the LTO steel. The lowest values of elongation at break and impact toughness of the steel were determined for the lower part of the pipe close to its inner surface. FCG tests at a low stress ratio (R = 0.1) did not reveal a significant change in its growth rate in degraded 17H1S steel compared to steel in the AR state. During tests at a stress ratio R = 0.5, the effect of degradation was more pronounced. The Paris' law region of the da/dN-∆K diagram for the LTO steel corresponding to the lower part of the pipe close to its inner surface was higher than those for the steel in the AR state and the LTO steel corresponding to the higher part of the pipe. Fractographically, a significant number of delaminations of non-metallic inclusions from the matrix were recognized. Their role in the embrittlement of steel, especially steel from the lower part of the pipe close to its inner surface, was noted.

Стан і розвиток способів розподілу гарячого металу на мірні довжини

Analysis of hot metal dividing methods into measured lengths from the point of view of providing the required quality of their ends after separation, as well as high performance methods is the aim of the work. This is especially important for the preparation of hot metal for subsequent processing, including rolling and tube rolling units, where high quality of the ends of the workpieces reduces the end cut and metal consumption ratios, and tube quality also improves the quality of rolled steel shells and pipes. Well-known literary and patent sources in the field of the separation of hot metal into measured lengths both during continuous casting of steel and in subsequent redistribution, are researched in this work. As a result of the analysis, it has been established that widely used methods for the separation of hot metal in practice cannot provide high quality pipe ends after separation, which increases the metal loss in subsequent redistribution. The most promising for the separation of hot metal into measured lengths in rolling and tube-rolling production is hot-abrasive cutting and cutting with rotary saws. They are becoming more common in production. The practical significance of the results presented in this paper are proposals for the use of progressive methods for separation of hot metal both in terms of high productivity and, above all, the required quality of the resulting ends after separation for subsequent redistribution. The development directions of the analyzed methods for the separation of hot metal are considered. A waste-free two-stage method has been proposed for dividing round hot billets into dimensional parts, which improve the quality of the ends for subsequent rolling of pipes.

Зміцнення інструменту для холодної роликової прокатки корозійностійких труб

The work is devoted to a topical technical problem - to increase the wear resistance of pipe tools for cold roller rolling of corrosion-resistant pipes, due to its significant cost and difficult working conditions. It is proposed to improve the technology of heat treatment of rolled tools for the production of corrosion-resistant pipes (mandrels, rollers, support strips) from steels 4Х5МФ1С and 60С2ХФА. Instead of the usual technology - tempering with tempering, tempering with tempering and subsequent ionic nitriding in plasma of two-stage vacuum-arc discharge in a modified installation "Bulat-6" in the laboratory of plasma technology. The microstructure of special samples of these steels on a scanning electron microscope (SEM) at different magnifications was studied. Their microhardness was determined using a microhardness tester PMT-3. A comparison of the microhardness of the samples after traditional treatment and the proposed. The wear resistance of the actual tool (mandrels made of 60С2ХФA steel) for cold roller rolling of particularly thin-walled corrosion-resistant pipes was studied directly during industrial tests in the factory. Studies of the microstructure on the REM of the nitrided layer after ion-plasma nitriding revealed a finely dispersed very strong ε-phase. Due to its presence in the surface layer, the surface hardness of nitrided parts increases due to the formation of stable in the process of heating carbides, nitrides, carbonitrides. Steel acquires high hardness on the surface, high wear resistance, high endurance, corrosion resistance. Tests of mandrels in the factory, which were additionally subjected to ionic nitriding, showed an increase in their stability by 25-30%. Also reduced the cost of processing the manufacture of pipes and improved the quality of the inner surface of the pipes (absence of films, cuts and other defects of corrosion-resistant pipes). Replacement of steel 60С2ХФA with secondary hardening steel 4Х5MФ1С for the manufacture of rollers and support bars in addition to improving the quality of the inner surface of the pipes increased the stability of the tool by 2.7-3 times. Keywords: rollers, support laths, mandrels, cold rolling, heat treatment, ionic nitriding.