Characteristics of tee tube forming deformation zone using plastic pressure-building medium

2000 ◽  
Vol 6 (6) ◽  
pp. 519-524 ◽  
Author(s):  
Debin Shan ◽  
Youngsuk Kim ◽  
Yan Lu ◽  
Sungtae Kim ◽  
Chenglu Wang
Keyword(s):  
Deformation Zone ◽  
Tube Forming

Simulation of vibration piercing of pipe blank at press

2020 ◽  
Vol 76 (11) ◽  
pp. 1128-1138
Author(s):  
S. R. Rakhmanov
Keyword(s):  
High Frequency ◽  
Deformation Zone ◽  
Pipe Blank ◽  
Equipment Operation ◽  
Metal Deformation ◽  
Technological Tool ◽  
High Frequency Vibrations ◽  
Pipe Blanks ◽  
Wave Phenomena

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.

scholarly journals Cold Forging Effect on the Microstructure of Motorbike Shock Absorbers Fabricated by Tube Forming in a Closed Die

2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui
Keyword(s):  
Material Flow ◽  
Cold Forging ◽  
Technological Parameters ◽  
Forming Process ◽  
Tube Forming ◽  
Shock Absorbers ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Of Products ◽  
Forming Defects

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.

Research on Temperature Changes and Microstructure Evolution of Steel Target after the Penetration by Copper Jet

2011 ◽  
Vol 311-313 ◽  
pp. 953-956
Author(s):  
Hao Chen ◽  
Gang Tao
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Temperature Distribution ◽  
Microstructure Evolution ◽  
Deformation Zone ◽  
Superplastic Deformation ◽  
Theoretical Formula ◽  
Temperature Changes ◽  
Normal Deformation ◽  
Steel Target

In order to study dynamic response of metal, this paper makes use of theoretical formula to investigate changes of temperature and grain size on steel target after the penetration of copper jet based on data gathered from the experiments. Deformed target penetrated by copper jet could be divided into superplastic deformation zone and normal deformation zone according to the different microstructure. Temperature distribution of each deformation zones is in turn calculated by two constitutive equations. The results indicate that areas with high temperature concentrate on the narrow zone near the penetrated channel. Then, the calculation of grain size conforms to the observation. It is obviously proven that the method used in this paper is trustworthy for calculating the changes of temperature and grain size of target caused by penetration.

scholarly journals Geology of the orogenic Cheminis gold deposit along the Larder Lake – Cadillac deformation zone, Ontario

2015 ◽  
Vol 52 (12) ◽  
pp. 1093-1108 ◽  
Author(s):  
Bruno Lafrance
Keyword(s):  
Deformation Zone ◽  
Volcanic Rocks ◽  
Tholeiitic Basalt ◽  
Hydrothermal Fluids ◽  
South Side ◽  
Shear Sense ◽  
Abitibi Subprovince ◽  
Deformation Features ◽  
Shear Sense Indicators ◽  
Host Rocks

The Larder Lake – Cadillac deformation zone (LLCDZ) is one of two major, auriferous, deformation zones in the southern Abitibi subprovince of the Archean Superior Province. It hosts the Cheminis and the giant Kerr Addison – Chesterville deposits within a strongly deformed band of Fe-rich tholeiitic basalt and komatiite of the Larder Lake Group (ca. 2705 Ma). The latter is bounded on both sides by younger, less deformed, Timiskaming turbidites (2674–2670 Ma). The earliest deformation features are F1 folds affecting the Timiskaming rocks, which formed either during D1 extensional faulting or during early D2 north–south shortening related to the opening and closure, respectively, of the Timiskaming basin. Continued shortening during D2 imbricated the older volcanic rocks and turbidites and produced regional F2 folds with an axial planar S2 cleavage. D2 deformation was partitioned into the weaker band of volcanic rocks, producing the strong S2 foliation, L2 stretching lineation, and south-side-up shear sense indicators, which characterize the LLCDZ. Gold is present in quartz–carbonate veins in deformed fuchsitic komatiites (carbonate ore) and turbiditic sandstone (sandstone-hosted ore), and in association with disseminated pyrite in altered Fe-rich tholeiitic basalts (flow ore). All host rocks underwent strong mass gains in CO2, S, K2O, Ba, As, and W, during sericitization, carbonatization, and sulphidation of the host rocks, suggesting that they interacted with the same hydrothermal fluids. Textural relationships between alteration minerals and S2 cleavage indicate that mineralization is syn-cleavage. Thus, gold was deposited as hydrothermal fluids migrated upward along the LLCDZ during contractional, D2 south-side-up shearing. The gold zones were subsequently modified during D3 reactivation of the LLCDZ as a dextral transcurrent fault zone.

Plastic Forming Processes Through Rotating Conical Dies1

2001 ◽  
Vol 68 (6) ◽  
pp. 894-902 ◽  
Author(s):  
D. Durban ◽  
G. Davidi ◽  
D. Lior
Keyword(s):  
Single Phase ◽  
Large Strain ◽  
Single Layer ◽  
Wall Friction ◽  
Nonlinear Ordinary Differential Equations ◽  
Tube Forming ◽  
Perfectly Plastic ◽  
Governing System ◽  
Plastic Forming ◽  
Exact Relations

Drawing and extrusion of single-phase and multilayered tubes through rotating conical dies is investigated within the framework of continuum plasticity. Large strain perfectly plastic J2 flow theory models constitutive behavior along with a radial-helical flow pattern. The governing system for a single-layer process is reduced to three coupled nonlinear ordinary differential equations. An approximate solution is developed for long and tapered working zones with low wall friction. That solution is used to simulate the field within each layer in composite tube forming. Exact relations are derived for the n-layered tube and it is shown that wall rotation can considerably reduce the required working loads. Dedicated to Professor Dietmar Gross on the occasion of his 60th birthday

Mathematical simulation of seamless pipes extrusion and rational calibration of die

2021 ◽  
Vol 77 (1) ◽  
pp. 70-79
Author(s):  
S. R. Rakhmanov
Keyword(s):  
Mathematical Simulation ◽  
Deformation Zone ◽  
Metal Flow ◽  
Flow Speed ◽  
Zone Length ◽  
Technology Application ◽  
Extrusion Press ◽  
Length Increase ◽  
Die Profile ◽  
Zone Parameters

Technology of seamless pipes production by extrusion enables to deform pipe workpieces made of low-plastic materials. However, low durability of the working instrument restricts the area of the technology application. The purpose of the work was to specify optimal parameters of technological processes of pipes extrusion. Minimization of energy and force parameters of the deformation zone and an increase of once-only metal deformation were accepted as criteria. They will enable to increase the presses productivity, increase durability of working instrument and accuracy of pipes geometric dimensions. A mathematical model of deformation zone and stressed state of pipe workpiece were elaborated. Influence of the die generatrix calibration and deformation zone parameters on the character of energy and force parameters change revealed. Dependence of energy and force parameters on the die calibration and geometric parameters of deformation zone for the press 50 MH was established. The results of mathematical simulation of pipes extrusion showed that along the whole deformation zone length, increase of metal flow speed results in an increase of tangential and normal stresses on the forming mandrel and calibrated die. The task of parametric optimization of die profile (calibration) was accomplished in interpretation of base variation Euler’s task for a determined functional of pipes extrusion. It was established that while the extrusion speed is increasing, the energy and force parameters of the deformation zone are getting pronounced dynamic character. At that, by optimization of die calibration, an increase of the extrusion press 50MH working instruments durability was reached, as follows: dies – by two times, mandrels – by 4 times, container bushes – by 40% and press-washers – by 2 times.

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