Modernization of Hot-Rolled Tubes Rolling Method

2017 ◽  
Vol 265 ◽  
pp. 1048-1052
Author(s):  
D.A. Pavlov ◽  
Aleksandr Aleksandrovich Bogatov ◽  
E.A. Pavlova
Keyword(s):  
Pipe Wall ◽  
Thickness Variation ◽  
Elongation Ratio ◽  
Piercing Mill ◽  
Pipe Wall Thickness ◽  
Wall Thickness Variation ◽  
Rolling Method ◽  
Skin Formation ◽  
Automatic Tandem Mill ◽  
Hot Rolled

A new method of hot-rolled pipes rolling on the automatic tandem mill is suggested. It consists of two rolling stands. This method allows achieving the rough pipe preovalisation before reaching the automatic mill. The rough pipe preovalisation provides even groove filling and the decrease of pipe wall thickness variation. The rough pipe preovalisation will allow increasing the elongation ratio from 1.5 to 2.0 on the lengthwise rolling stand no. 1 and decreasing the elongation ratio on the piercing mill, therefore the chance of rolling skin formation on the external surface of the pipe is decreased. The way to reduce the probability of the formation of a guide mark defect due to the kinematic tension during rolling on a stub mandrel with rough tube preovalisation is investigated. The influence of the kinematic tension factor on the pipe forming in the groove taper at a lengthwise rolling with rough tube preovalisation is explored.

API 5L X80 ERW Pipes: TenarisConfab and Usiminas Development

2006 ◽  
Author(s):  
Juliana E. Roza ◽  
Marcelo C. Fritz ◽  
Marco A. Tivelli ◽  
Ronaldo C. Silva ◽  
Lu´cio S. Miranda ◽  
...  
Keyword(s):  
Pipe Wall ◽  
High Strength Steels ◽  
High Strength ◽  
Mechanical Resistance ◽  
Electric Resistance ◽  
Pipe Wall Thickness ◽  
High Toughness ◽  
Operation Costs ◽  
Electric Resistance Welding ◽  
Hot Rolled

The utilization of high strength steels can decrease, both, installation and operation costs of a new pipeline, since the increase of mechanical resistance can reduce the pipe wall thickness and, consequently, the weight of the pipe. For this purpose, the manufacture of electric resistance welding (ERW) pipes is recent, and it comes as an opportunity for gas pipelines, mainly onshore projects. As a function of their larger productivity, ERW pipes are more economically attractive than those produced by seamless and SAW processes. TenarisConfab and Usiminas, through studies and investments in manufacturing processes, have been working to increase their skills, in order to supply API 5L X80 ERW pipes. The steel elaborated by Usiminas is low C, high Mn, Nb, V and Ti microalloyed, and with additions of Cr and Mo, aiming to produce hot rolled coils with acicular microstructure, achieved as a combination between its chemical composition and higher cooling rates after hot rolling. The results in φ18” (457 mm) × 0,469” (11,91 mm) pipes are presented in this article. High toughness values reached at very low temperatures suggest that X80 ERW pipes developed by TenarisConfab and Usiminas may be an excellent option of choice for onshore projects that request pipes in diameters up to 20” (508 mm) and thickness up to 0.500” (12.7 mm).

scholarly journals On the stress state of a pressurised pipe with an initial thickness variation, subjected to non-homogeneous internal corrosion

2019 ◽  
Vol 121 ◽  
pp. 01013
Author(s):  
Shixiang Zhao ◽  
Yulia Pronina
Keyword(s):  
Pipe Wall ◽  
Numerical Procedure ◽  
Initial Boundary ◽  
Structural Instability ◽  
Thickness Variation ◽  
Initial Thickness ◽  
Minimum Thickness ◽  
Internal Corrosion ◽  
Pipe Wall Thickness ◽  
Initial Boundary Value

The paper concerns 2D problem of an elastic thick-walled pipe with an initial thickness variation, subjected to internal pressure and mechanochemical corrosion. The inner perimeter of the pipe cross-section is elliptical, while the outer is circular. The linear Dolinskii corrosion kinetics model is used. In the general case, structural instability of initial boundary value problems with unknown evolving boundaries can cause the divergence of numerical procedures when modelling the processes under study. It is observed that the attempts to circumvent the divergence of numerical procedure can suppress the manifestation of mechanochemical effect and yield inaccurate results. Thus, it is necessary to find a compromise between competing computational processes. Calculations revealed that the variation of the initial pipe wall thickness within the acceptable pipe wall tolerance can noticeably accelerate the growth of stresses and, consequently, reduce the durability of the pipe. The applicability of analytical solutions for a perfect circular pipe with a reduced thickness, equal to the minimum thickness of the imperfect pipe, to the case under study is also discussed.

scholarly journals ACCURACY WALL SICKNESS OF HOT-DEFORMED PIPES STATISTICAL ANALISIS

2020 ◽  
pp. 113-120
Author(s):  
Oleksandr Sobolenko ◽  
Petro Drozhzha ◽  
Nataliia Dorosh ◽  
Lina Petrechuk
Keyword(s):  
Wall Thickness ◽  
Pipe Wall ◽  
Graphical Analysis ◽  
High Ratio ◽  
Longitudinal Rolling ◽  
Pipe Wall Thickness ◽  
Production Complex ◽  
Metal Deformation ◽  
Hot Rolled ◽  
Quantitative Indicators

Pipe-rolling units with an automatic mill are a aggregate production complex that produces hot-rolled pipes of various sizes. The technological process of seamless pipes production, has many stages: flashing the billet into a sleeve, longitudinal rolling in gauge, running in a oblique rolling mill, calibrating and reducing the diameter. Each stage significantly affects the accuracy of the geometric dimensions of the pipes. One of the main parameters characterizing the accuracy of the pipes is their transverse difference namely the size and the nature of the distribution of the pipe wall thickness in the cross section. A significant reserve for saving metal is increasing the accuracy of seamless pipes to avoid different pipe wall thickness. Different pipe wall thickness makes it difficult to get quality pipe screw-thread.The conditions of metal deformation at an injection molding machine with an automatic machine do not exclude the presence of fluctuation of the pipe wall thickness. The best characteristic of the accuracy of finished pipes will be the knowledge of quantitative indicators of the transverse difference of their end sections. The purpose of this work is to determine the variation in wall thickness of hot-rolled casing by means of mathematical statistics methods.The use of statistical data processing methods makes it possible to predict the seamless pipe difference indicator. A statistical analysis of the wall thickness indicator of the end sections showed a high ratio of wall thickness symmetry. An effective way to minimize the symmetric difference component is to optimize the deformation modes along the pipe wall. In this case, a graphical analysis of the distribution of wall thickness showed that the actual difference varies in stochastic dependence. To clarify the general form of the random periodic component of such a dependence, it is advisable to apply methods of harmonic analysis, which will allow us to develop a mathematical model for determining the accuracy of pipes.

Development of a mathematical model of the influence of wall thickness on the strain rate when profiling pipes by drawing

2020 ◽  
pp. 49-52
Author(s):  
R.A. Okulov ◽  
N.V. Semenova
Keyword(s):  
Mathematical Model ◽  
Strain Rate ◽  
Wall Thickness ◽  
Pipe Wall ◽  
Strain Intensity ◽  
Thickness Strain ◽  
Pipe Wall Thickness

The change in the intensity of the deformation of the pipe wall during profiling by drawing was studied. The dependence of the strain intensity on the wall thickness of the workpiece is obtained to predict the processing results in the production of shaped pipes with desired properties. Keywords drawing, profile pipe, wall thickness, strain rate. [email protected]

Mechanics of Conventional Spinning

1963 ◽  
Vol 85 (4) ◽  
pp. 346-350 ◽  
Author(s):  
H. C. Sortais ◽  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Wall Thickness ◽  
Pure Aluminum ◽  
Tangential Force ◽  
Deformation Energy ◽  
Thickness Variation ◽  
Force Component ◽  
Commercially Pure ◽  
Conventional Spinning ◽  
Wall Thickness Variation ◽  
Experimental Values

In conventional spinning of cones, the cone-wall thickness variation was studied using blanks of 1100-0 commercially pure aluminum sheet of 0.050-in. thickness. The results revealed that the radial stress induced in the unspun flange is the major cause of nonuniform wall thickness of spun cones. The theoretical tangential force component was derived by use of the deformation energy method. Qualitative agreement was found between the theoretical and the experimental values of tangential force component in the underspinning conditions.

Fließpressen hohler Wellen mit Wanddickenvariation/Cold forging of hollow shafts with wall thickness variation – Numerical investigation of a hollow forward extrusion process with adjustable deformation zone

2020 ◽  
Vol 110 (10) ◽  
pp. 684-688
Author(s):  
Alexander Weiß ◽  
Mathias Liewald
Keyword(s):  
Numerical Investigation ◽  
Metal Forming ◽  
Extrusion Process ◽  
Cold Forging ◽  
Thickness Variation ◽  
Part Geometry ◽  
Forming Technology ◽  
Wall Thickness Variation ◽  
The University ◽  
Hollow Shafts

Die Fertigung von Hohlwellen mit komplexer Innengeometrie bedingte bisher meist aufwendige Prozessrouten. Ein am Institut für Umformtechnik der Universität Stuttgart entwickeltes Kaltfließpressverfahren soll nun die wirtschaftliche und flexible Fertigung von Hohlwellen mit Wanddickenvariation ermöglichen. In diesem Beitrag werden das Verfahren beschrieben und die Ergebnisse der numerischen Untersuchung des Einflusses der Werkzeugkinematik auf die erzielbare Pressteilgeometrie dargelegt.   Usually, the production of hollow shafts with complex internal geometry by cold forging requires extensive process routes. A novel cold forging process developed at the Institute for Metal Forming Technology at the University of Stuttgart allows for an economical and flexible production of hollow shafts. This article describes the manufacturing process and presents the results of a numerical investigation for determining the influence of tool kinematics on the achievable part geometry.

Leak Testing

2021 ◽  
pp. 143-147
Author(s):  
Charles Becht
Keyword(s):  
Wall Thickness ◽  
Pipe Wall ◽  
Piping System ◽  
Pipe Wall Thickness ◽  
Pressure Testing ◽  
Leak Testing ◽  
Piping Systems ◽  
Design Pressure ◽  
Important Test

While the exercise of pressurizing a piping system and checking for leaks is sometimes called pressure testing, the Code refers to it as leak testing. The main purpose of the test is to demonstrate that the piping can confine fluid without leaking. When the piping is leak tested at pressures above the design pressure, the test also demonstrates that the piping is strong enough to withstand the pressure. For large bore piping where the pipe wall thickness is close to the minimum required by the Code, being strong enough to withstand the pressure is an important test. For small bore piping that typically has a significant amount of extra pipe wall thickness, being strong enough is not in question. Making sure that the piping is leak free is important for all piping systems.

Sign in / Sign up

Export Citation Format

Share Document