Development of a method and equipment for testing materials for alternating bending during piercing in screw rolling mills

2020 ◽  
pp. 29-34
Author(s):  
B. A. Romantsev ◽  
◽  
A. S. Aleshchenko ◽  
E. R. Guseynov ◽  
V. Yu. Tsyutsyura ◽  
...  
Keyword(s):  
Deformation Zone ◽  
Rolling Mill ◽  
Pipe Production ◽  
Test Machine ◽  
Shell Wall ◽  
Original Design ◽  
Plastic Bending ◽  
Deformed State ◽  
Hot Rolled ◽  
Alternating Bending

Hot-rolled pipe production is complicated process of metal treatment by pressure and as a rule it has three operations of form charging: piercing, plugging, calibration or reduction. Each of them is characterized by complex schemes of stress-deformed state which promotes either formation or detection of various defects. Hot billet piercing at screw piercing rolling mill is widely used for pipe production for its high output and getting the shells of long length. But this operation of form charging of the metal is realized under the conditions of complicated stress-deformed state with cyclic alternating bending of all metal layers. Defects appearing on the outside surface of the shell such as captures and cracks is caused by plastic bending of shell wall, which is followed by alternating stress and deformation at the inlet and outlet cone of deformation zone in consequence of four times plastic bending of the wall. Shell wall is influenced by compression stress of the working rolls and guides. The less favorable scheme of stress state with tensile stress arises on the shell surface between the rolls and the guide. And as a results it generates and increases the defects on the outside surface. Theoretical and experimental research of deformation and speed conditions of billet piercing process for screw piercing rolling mill is presented in the work. Statistic data of production mills which operate in TRA 50-200 and TRA 159-426 lines were used for the research. All the calculations were done with use of applied software and test machine of original design with crank and connecting rod mechanism was constructed. The machine carries out the process of alternating plastic bending which is in maximum close to the conditions taking place in deformation zone of screw piercing rolling mill. Definition of rational configuration of sample shape was determined. Process plasticity of the metal of hot samples was analyzed as well. The samples were made from hot-rolled bars of different steel grades.

Research of stamping of unequal channel bars. Part 4. Deformed state of the workpiece when extruding channels. 2. Deformations under the punch end

2021 ◽  
pp. 53-57
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plastic Deformation ◽  
Plane Strain ◽  
Deformation Zone ◽  
Plastic Deformation Zone ◽  
Die Forging ◽  
Deformed State

Determination of the deformed state of the workpiece at free extrusion of channels is considered. Formulas are obtained for determining the accumulated deformations at a given point of the plastic deformation zone and extruded walls of the product for any punch working stroke. Keywords: die forging, extrusion, misalignment, punch, matrix, plane strain, accumulated deformations, hardening. [email protected]

scholarly journals Calculating Power Parameters of Rolling Mill Based on Model of Deformation Zone with Four-Roll Passes

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 73
Author(s):  
Marina N. Samodurova ◽  
Olga I. Karandaeva ◽  
Vadim R. Khramshin ◽  
Ivan V. Liubimov
Keyword(s):  
Mathematical Models ◽  
Deformation Zone ◽  
Rolling Mill ◽  
Process Conditions ◽  
Complex Deformation ◽  
Multivariable Control Systems ◽  
Digital Twins ◽  
Mill Equipment ◽  
Metal Treatment ◽  
The Impact

Making “digital twins” for rolling processes and mill equipment should begin with the development of mathematical models of the deformation zone. The deformation zone of two-high flat mill rolling have been studied in detail, relevant models are available in many academic papers. However, the same cannot be said about the most complex deformation zones in stands with multi-roll gauge. Therefore, the task of their reliable mathematical description is of immediate interest. The development of mathematical models is necessary for the design of new wire mills and rolling-drawing units. The combination of rolling in stands with multi-roll gauge and drawing is a promising direction in the production of wire from difficult-to-form steels and alloys. Digital models for pressure-based metal treatment are also necessary for calculating the rolling-mill power parameters during the development of new assortments at the operating mills. The models of deformation zones present the basis for developing the multivariable control systems of process conditions of continuous mills. This research is devoted to the study of the deformation zone and the development of a procedure for calculating the power parameters of rolling in a stand with four-roll passes. The solution of these challenges is given using the example of an operating five-stand wire mill. The authors analysed the known analytical dependencies for calculating the rolling mill force and torque. A mathematical model of the deformation zone and a program for calculating the power parameters have been developed. The paper compares the results obtained from calculations based on analytical dependence and on modelling. A comparison with the experimental parameters obtained at the mill is given. The authors assess the feasibility of using the known formulas and analyse the impact of the front and rear tensions on the power parameters of rolling mill. The problem of developing an automatic tension control system for continuous mills with multi-roll groove is substantiated.

scholarly journals Task based conceptual design of a testing machine

2019 ◽  
Vol 287 ◽  
pp. 01008
Author(s):  
Hrayr Darbinyan
Keyword(s):  
Conceptual Design ◽  
Power Transmission ◽  
Mechanical Design ◽  
Design Method ◽  
Testing Machine ◽  
General Concept ◽  
Test Machine ◽  
Concept Design ◽  
Original Design ◽  
Design Cycle

A novel approach of task based conceptual design(TBCD) has been successfully used as direct guider and efficient developer of unique mechanical structures for many cases of mechanical design. Nearly a decade long efforts of elaboration of efficient every day usage formats for this method have been ended in convenient design pages suitable and applicable for revealing, describing, visualizing and managing the data necessary for organizing the design process from task definition to solutions satisfying original design tasks. The aim of current study is to show steps of a solution generation within frames of a single design cycle and extend this action over consecutive design cycles. Those steps are described from standpoint of general concept design method starting from key model and finished with final aggregation matrice as ultimate step of a single design cycle. Unified mathematical expressions are used for introduction and description of all worked out and developed components of conceptual design. The paper is arranged in a way to show gradual steps of conceptual design(CD) of a power transmission system – a pipe wrench life test machine.

A model for the run out table cooling in a compact rolling mill

2004 ◽  
Vol 120 ◽  
pp. 513-518
Author(s):  
L. Hernandez ◽  
M. P. Guerrero-Malta ◽  
L. A. Leduc ◽  
R. Colas
Keyword(s):  
Rolling Mill ◽  
Steel Strip ◽  
Cooling Capacity ◽  
Water Jets ◽  
Fundamental Part ◽  
Different Types ◽  
Pressure Water ◽  
Number Flow ◽  
Hot Rolled ◽  
Hot Rolled Steel

A fundamental part of hot rolling of steel strip processing takes place in the run out table of industrial mills. It is in this place that most of the material transforms from austenite to ferrite. Cooling of the steel strip is promoted by high and low pressure water jets coming from different types of headers. The efficiency of such headers depends on the type of header, their flow and position, as well as the speed at which the strip is delivered from the rolling mill. Computer simulation is carried out by means of a two-dimensional finite difference model that takes into account the number, flow, position and type of headers used along the run out table. It is found that the cooling capacity of the headers is affected by the velocity of the hot rolled steel strip.

Fatigue properties of a TiNi shape-memory alloy wire subjected to bending with various strain ratios

2003 ◽  
Vol 217 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Y Furuichi ◽  
H Tobushi ◽  
T Ikawa ◽  
R Matsui
Keyword(s):  
Fatigue Life ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Strain Ratio ◽  
Fatigue Properties ◽  
Test Machine ◽  
Shape Memory Alloy Wire ◽  
Alloy Wire ◽  
Rotating Bending ◽  
Alternating Bending

A fatigue-test machine for alternating bending of a wire under strain-controlled conditions was developed. Bending-fatigue tests on a TiNi shape-memory alloy wire were then performed for various strain ratios. The results obtained can be summarized as: (1) the fatigue life curves under alternating bending and pulsating bending, as expressed by the relationship between maximum strain and the number of cycles to failure, systematically follow the order of strain ratio; (2) the larger the strain ratio, the longer the fatigue life; (3) the fatigue life under rotating bending is shorter than that under alternating bending; (4) the increase in temperature during cyclic bending becomes larger in the order: rotating bending, alternating bending, pulsating bending. The fatigue life decreases in proportion to the increase in temperature; and (5) the fatigue limit of strain for alternating bending, pulsating bending and rotating bending is in the region of R-phase transformation.

scholarly journals Quality improvement of calibrated steel by surface deformation. Part 1. Determination of the stressed state of cylinderical parts during orbital surface deformation

2020 ◽  
Vol 63 (10) ◽  
pp. 802-807
Author(s):  
S. A. Zaides ◽  
. Pham Van Anh
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Deformation Zone ◽  
Surface Deformation ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Machining Performance ◽  
Cylindrical Parts ◽  
Practice Methods ◽  
Hot Rolled

Cold drawn calibrated steel is an effective blank for the manufacture of low-rigid cylindrical parts such as shafts and axles. High accuracy of the diametric size along the length of the workpiece, low surface roughness, increased hardness and strength of the surface layer compared to hot rolled products allow us to produce a variety of parts with high metal utilization and high machining performance. The main disadvantage of calibrated metal is the residual stresses that occur during pressure treatment. To reduce or change the nature of the distribution over the cross section, it is proposed to use small plastic deformations in the surface layer of the hire. Known in practice methods of surface plastic deformation (PPD) usually lead to the curvature of non-rigid workpieces. To intensify the stress-strain state in the deformation zone, we propose a method of orbital surface deformation. Based on the finite element modeling, influence of the main parameters of orbital surface deformation on stress state in the deformation zone and residual stresses in the finished products is considered. Compared with the traditional PPD process, the stress intensity during orbital surface deformation will increase by 10 – 15 %. The residual compressive stresses that form in the surface layers reach 70 – 85 % of the material tensile strength. In the second part of the article, it is supposed to provide information on a more effective method of surface deformation and on the change in initial residual stresses that are formed during the calibration of cylindrical rods.

Surface Finish Enhancement of Hot-Rolled Strips on the 2000 Wide-Strip Rolling Mill Using Mathematical Modeling at Novolipetsk Steel

2019 ◽  
Vol 49 (10) ◽  
pp. 703-708 ◽  
Author(s):  
V. A. Pimenov ◽  
A. I. Dagman ◽  
A. K. Pogodaev ◽  
D. A. Kovalev ◽  
N. N. Zhovnodii
Keyword(s):  
Mathematical Modeling ◽  
Surface Finish ◽  
Rolling Mill ◽  
Strip Rolling ◽  
Wide Strip ◽  
Hot Rolled

Hot-Rolled TRIP Steels Based on Dynamic Transformation of Undercooled Austenite

2010 ◽  
Vol 654-656 ◽  
pp. 250-253 ◽  
Author(s):  
Wang Yue Yang ◽  
Long Fei Li ◽  
Yun Yang Yin ◽  
Zu Qing Sun ◽  
Xi Tao Wang
Keyword(s):  
Volume Fraction ◽  
High Volume ◽  
Test Machine ◽  
Compression Tests ◽  
Controlled Cooling ◽  
Thermomechanical Process ◽  
Trip Steels ◽  
Dynamic Transformation ◽  
Hot Rolled ◽  
Undercooled Austenite

A novel thermomechanical process to manufacture hot-rolled transformation-induced plasticity (TRIP) steels was developed based on dynamic transformation of undercooled austenite (DTUA). Between DTUA and the isothermal bainitic treatment, only one-step controlled-cooling was required. The microstructure evolution of hot-rolled C-Mn-Si and C-Mn-Al-Si TRIP steels based on DTUA was investigated by hot uniaxial compression tests using a Gleeble1500 simulation test machine. The results indicated that during DTUA, the kinetics of ferrite formation was fast, the volume fraction of ferrite formed was determined by applied strain. In comparison with the process based on static transformation of austenite, a more uniform multiphase microstructure with fine ferrite grains was formed, the bainite packets were small and had relatively random orientations, the retained austenite distributed uniformly and had relatively high volume fraction. Hot-rolled TRIP steels based on DTUA demonstrated better mechanical properties, especially for C-Mn-Al-Si TRIP steel.

Modelling and simulation of deformation zone in cross rolling mill

1997 ◽  
Vol 68 (5) ◽  
pp. 220-223
Author(s):  
Li Zhiqiang ◽  
Lu Yuqiu ◽  
Lu Shouli
Keyword(s):  
Deformation Zone ◽  
Rolling Mill ◽  
Modelling And Simulation ◽  
Cross Rolling

EFFECT OF ASYMMETRICAL STAND STIFFNESS ON HOT ROLLED STRIP SHAPE

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5734-5739 ◽  
Author(s):  
DIANYAO GONG ◽  
JIANZHONG XU ◽  
ZHENGYI JIANG ◽  
XIAOMING ZHANG ◽  
XIANGHUA LIU ◽  
...  
Keyword(s):  
Rolling Mill ◽  
Deformation Analysis ◽  
Rolled Strip ◽  
Force Distribution ◽  
Influence Coefficient ◽  
Single Wave ◽  
Hot Rolled Strip ◽  
Strip Shape ◽  
Roll Deformation ◽  
Hot Rolled

The difference of elastic springs between the operating side (OS) and driving side (DS) of rolling mill has a significant influence on the strip shape not just the strip thickness. Based on the slit beam and roll deformation theories, the roll force distribution was analysed considering the asymmetric stiffness of the OS and DS of rolling mill, and the work roll and backup roll deformation equations were deduced respectively, and the thickness distribution in lateral direction of the hot rolled strip at exit was discussed. Using the roll elastic deformation analysis software which was developed previously based on the influence coefficient method, the roll flattening distribution, roll pressure distribution and the rolling force distribution caused by the asymmetric stand stiffness were calculated and analysed, and the exit strip profile of the rolling mill was also presented. The relationship between the mill stiffness difference and the strip wedge shape or single wave was obtained. Effect of the upstream asymmetric mill on strip crown and flatness of the downstream stands was discussed.

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