Study and Build-Up of Deformation Zone at Cutting of Thin-Walled Tube by Torsion

2017 ◽  
Vol 746 ◽  
pp. 16-21
Author(s):  
S.G. Simagina
Keyword(s):  
Deformation Zone ◽  
Heating Temperature ◽  
Compression Force ◽  
Angular Deflection ◽  
Thin Walled Tube ◽  
Temperature Impact ◽  
Thin Walled ◽  
Force Range ◽  
Intensive Development

Intensive development of Russian aviation and aerospace industries put an emphasis to the problem of quality of using materials and workpieces and to the value of technical and economical indexes in the context of planned production level [1, 2]. Waste-free technologies are preferred. Cutting by torsion or cutting by shear are preferable technologies if thin-walled tube cutting is the main blanking operation. Build-up of workpiece deformation zone plays an important role in the cutting process. Deformation zone determines stability of details during further processing and exploitation. An extended research was conducted about tube separation process using torsion with an active counterpressure. Some parameters was defined in the result of research, in particular: distribution of deformation zone along length and thickness of workpiece, angular deflection and compression force and workpiece heating temperature impact on build-up of whisker disposition in the cut zone. It allows identifying optimum compression force range and temperature conditions. Compliance with recommended practices allows conducting thin-walled tube separation simultaneously with build-up on the workpieces whisker structure that is fortunate for further pressure treatment and exploitation.

Investigation on the influence of mandrel on the forming quality of thin-walled tube during free bending process

2021 ◽  
Vol 72 ◽  
pp. 215-226
Author(s):  
Cheng Cheng ◽  
Hao Chen ◽  
Jiaxin Guo ◽  
Xunzhong Guo ◽  
Yuanji Shi
Keyword(s):  
Forming Quality ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Free Bending

Improving in surface quality of precision thin-walled pipes

2021 ◽  
pp. 557-559
Author(s):  
A.A. Filatov ◽  
O.V. Sokolova ◽  
E.V. Lagoshina
Keyword(s):  
Surface Quality ◽  
Deformation Zone ◽  
Original Method ◽  
Axial Forces ◽  
Thin Walled ◽  
Periodic Rolling

The causes for the occurrence of axial forces during the cold periodic rolling in the deformation zone are considered. Original method for solving of the axial forces minimization to increase the productivity of mills and the quality of the finished product is presented.

A New Stress Mathematical Model of Deformation Zone while Straightening Thin-Walled Tube

2013 ◽  
Vol 652-654 ◽  
pp. 1488-1493
Author(s):  
Zi Qian Zhang ◽  
Yun Hui Yan ◽  
Hui Lin Yang
Keyword(s):  
Mathematical Model ◽  
Theoretical Model ◽  
Plastic Zone ◽  
Deformation Zone ◽  
Shell Theory ◽  
Theoretical Calculations ◽  
Technological Parameters ◽  
Membrane Shell ◽  
Thin Walled Tube ◽  
Thin Walled

As there was no precise theoretical model for predicting the stress of deformation zone while straightening thin-walled tube, some technological parameters depended mostly on the experience of workers and on the results of trials, therefore by means of the membrane shell theory the equilibrium differential equations of stress is obtained firstly, then we analyze the strain of deformation zone, finally lead to a new theoretical model for predicting the stress in the elastic and plastic zone. Subsequently the simulated experiments have been done, the results show that the theoretical calculations coincide well with the simulated results, the errors are within 1％of the calculations, it is testified that the model is correct and efficient for the thin-walled tube straightening.

Effect of frictions on cross section quality of thin-walled tube NC bending

2006 ◽  
Vol 16 (4) ◽  
pp. 878-886 ◽  
Author(s):  
He YANG ◽  
Rui-jie GU ◽  
Mei ZHAN ◽  
Heng LI
Keyword(s):  
Cross Section ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Nc Bending

Preparation and Properties of Thin Walled Copper Tube by a Short Process Method

2010 ◽  
Vol 148-149 ◽  
pp. 732-735
Author(s):  
Bao Long Yuan ◽  
Zi Dong Wang ◽  
Xiang Ming Li ◽  
Chun Jing Wu
Keyword(s):  
Cooling Water ◽  
Solidification Structure ◽  
Copper Tube ◽  
Water Volume ◽  
Columnar Crystal ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Surface ◽  
Process Method

Thin walled copper tube is prepared in vacuum melting and argon protecting continuous unidirectional solidification equipment by a short process method. The size of the thin walled copper tube is ф39×1.8 mm. The effect of process parameters on the solidification structure and the surface quality of the thin walled copper tube is investigated. The mechanical properties and electrical properties are tested and analyzed. The results show that the thin walled tube with columnar crystal structure and good quality surface can be obtained continuously and stably under the most appropriate process of the melting temperature is between 1423K and 1453K, the cooling water volume is 0.2～0.5m3•h-1, the cooling distance is 50mm, the drawing speed is not higher 20m•h-1. The elongation can reach 60%, and conductivity can reach 102.6%IACS.

An Inverse Method for Investigating Deformation Zone Temperatures in Metal Cutting

1991 ◽  
Vol 113 (2) ◽  
pp. 129-136 ◽  
Author(s):  
D. A. Stephenson
Keyword(s):  
Deformation Zone ◽  
Inverse Method ◽  
Metal Cutting ◽  
Empirical Studies ◽  
Cutting Temperature ◽  
Steady State Temperature ◽  
Average Deformation ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Effective Source

A major obstacle in verifying metal cutting temperature models and including thermal variables in empirical studies is the experimental difficulty of measuring physically meaningful cutting temperatures. This is especially true for deformation or shear zone temperatures, which influence the mechanical properties of the work material. This paper describes an inverse method for investigating deformation zone temperatures in end turning tests on thin-walled tubes. The method is based on analytical solutions for the quasi-steady state temperature distributions in a thin-walled ring heated by a rotating temperature source and a thin-walled tube heated by a helically moving source; using these solutions, remote temperature measurements on the tube can be used to back-calculate an effective source temperature which corresponds physically to an average deformation zone temperature. The method has been used in a broad range of experiments on steel, brass, aluminum, and cast iron to verify cutting temperature models. Sample calculations and infrared thermograms from these experiments are used to illustrate the application of the method.

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.

NICROBRAZ 50

Alloy Digest ◽  
1994 ◽  
Vol 43 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Honeycomb Structures ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Low Solubility

Abstract NICROBRAZ 50 is a low-melting, free-flowing filter metal for honeycomb structures and thin-walled tube assemblies. It has low solubility. This datasheet provides information on composition, physical properties, and hardness. It also includes information on corrosion resistance as well as joining. Filing Code: Ni-460. Producer or source: Wall Colmonoy Corporation.

scholarly journals Optimal Design of the Shape of a Non-Ball Mandrel for Thin-Walled Tube Small Radius Cold Bending

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1221
Author(s):  
Lu Bai ◽  
Jun Liu ◽  
Ziang Wang ◽  
Shuanggui Zou
Keyword(s):  
Ideal Point ◽  
Small Radius ◽  
Grey Wolf Optimizer ◽  
Forming Quality ◽  
Hollow Section ◽  
Cold Bending ◽  
Bending Process ◽  
Before And After ◽  
Thin Walled Tube ◽  
Thin Walled

In the field of cold bending, it is necessary to use ball mandrels, especially to bend thin-walled tubes with a small radius. However, the bending process with a ball mandrel is complex and expensive, and it is easy to jam the core ball inside the tube. To solve these issues, we designed two kinds of hollow non-ball mandrel schemes with low stiffness that were suitable for the small radius bending of thin-walled tubes. We evaluated the forming quality of cold bending numerically and the influence of the hollow section length and thickness on the forming indices. Our results showed that the thickness of the hollow section has a greater influence on forming quality than the length. As the hollow section’s thickness increased, the wrinkling rate first declined by approximately 40% and then increased by above 50%. When the thickness was 11 mm in scheme 1 and 13 mm in scheme 2, the wrinkling rate reached minimum values of 1.32% and 1.50%, respectively. As the hollow section’s thickness increased, the flattening rate decreased by more than 60% and the thinning rate increased by about 40%. A multi-objective optimization of forming indices was carried out by ideal point method and grey wolf optimizer. By comparing the forming results before and after optimization, the feasibility of using the proposed hollow mandrel was proved, and the hollow mandrel scheme of standard cylinder is therefore recommended.

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.

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