Optimization of Pipe Induction Bending Process Parameters

Author(s):  
T. S. Kathayat ◽  
Rajesh K. Goyal ◽  
Richard Hill ◽  
Tushal Kyada

Hot pushed induction heating is a bending process used to bend pipes having a small bending radius with a large diameter. This is a complex process since it involves mechanical process of bending and thermal process of localized induction heating. This paper deals with the optimization of induction bending process parameters such as bending speed, water flow rate, water pressure, air pressure and induction coil to water coil distance. Mother pipes of size 464 mm OD × 20.60 mm and grade API 5L X65MS/MO were used to make trial bends of 5D radius in 30° angle. Trial bends were subjected to mechanical tests and microstructural analysis to evaluate the effects of selected process parameters.

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiurong Fang ◽  
Jia Lu ◽  
Junfeng Wang ◽  
Jinhui Yang

The parameters of induction heating of large-diameter pipes have a direct effect on the final processing quality of the elbow, and the complexity of multifield coupling of magnetothermal force in induction heating can make it impossible to quantitatively optimize the design parameters of the induction heating device. In this paper, X80 pipeline steel induction heating is taken as the research object, and a corresponding numerical model is established. The influence of induction heating process parameters on the heating temperature of pipeline steel under the skin effect is determined. First, the influence of process parameters on the heating effect of pipeline steel is quantified by orthogonal test. Then, taking the optimum temperature difference between the inner and outer wall of X80 pipeline steel during the induction heating process as a target, the optimal process parameter set of the pipe induction heating is determined by using neural network genetic algorithm. Finally, comparing the relevant test criteria of the regression equation, the optimum mathematical prediction model of the outer wall temperature of the pipe induction heating process is obtained, which provides a theoretical basis for optimization of the process parameters of the pipe-based induction heating device.


2017 ◽  
Vol 62 (4) ◽  
pp. 2339-2342
Author(s):  
G. Junak ◽  
M. Cieśla ◽  
J. Tomczak

AbstractThis paper addresses numerical analyses of the bending process for tubes made of the X70 steel used in gas distribution pipe-lines. The calculations performed under the research involved simulation of processes of tube bending with local induction heating. The purpose of these calculations was to establish process parameters making it possible to develop pipe bends of geometric features conforming with requirements of the applicable standards. While performing the calculations, an analysis was conducted to determine the probability of occurrence of folding and fractures according to the Cockcroft-Latham criterion.


Author(s):  
Y. Ding ◽  
M. Yetisir ◽  
H. McDonald

The induction bending process using local induction heating is widely used to produce large diameter pipes with relatively small bend radii at low tooling cost. This process was considered for the fabrication of stainless steel feeder pipes for CANDU® reactors instead of cold and warm bending processes. Wall thickness measurements were performed, before and after bending, using an ultrasonic testing method on a number of test bends fabricated with this induction bending process. Residual stress measurements have been performed on a test bend by X-ray diffraction. A numerical model has been developed using LS-DYNA® to predict the residual stress and the deformed shape of these bends. The numerical model has also been used to study the effect of some key input parameters, such as bending speed, bending temperature, process parameters of induction heating and cooling, and the yield strength of the feeder material. This information can be used to improve the bending process such that lower residual stress and more uniform wall thickness can be achieved. In this paper, the simulation work is summarized and the comparison between the simulation results and the measurement data are presented.


2011 ◽  
Vol 194-196 ◽  
pp. 2204-2208
Author(s):  
Jian Zhang ◽  
Tong Mei Xiao ◽  
Liang Chu ◽  
Da Sen Bi

FEM simulations of squashing and bending process of large diameter elbow was applied to analyze the influence of squashing velocities, one of the key process parameters, on the deformation of the tube. In this study the squashing distance of first step is 300mm after several simulation attempts, corresponding to different squashing speeds and different bending velocities of second step. The simulation results of different velocities are compared and discussed. In the end the final velocities of the two steps are given.


2012 ◽  
Vol 472-475 ◽  
pp. 997-1002 ◽  
Author(s):  
Jian Guang Wang ◽  
Mei Zhan ◽  
Tao Huang ◽  
He Yang

The significant die unfittingness and springback, occuring during the numerically controlled (NC) bending process of large diameter thin-walled CT20 titanium alloy tube, has an obvious influence on the shape and the geometrical precision of the bent tube, furthermore on the assembly precision and the sealing capability. The changing rules of die fittingness and springback of large diameter thin-walled CT20 titanium alloy tube under different bending parameters were investigated and the mechanism was analysed using finite element method (FEM) in this paper. The result shows that the springback of large diameter thin-walled CT20 titanium alloy tube is more significant than that of aluminum alloy and stainless steel tubes with the same specification. The die fittingness has a connection with the tangent compressive stress on the intrados of the tube before springback, the larger the tangent compressive stress, the worse is the die fittingness.The results may provide a significant guide to the control of bending radius and bending angle for large diameter thin-walled titanium alloy tube NC bending.


Author(s):  
Song Gao ◽  
Tonggui He ◽  
Qihan Li ◽  
Yingli Sun ◽  
Jicai Liang

The problem of springback is one of the most significant factors affecting the forming accuracy for aluminum 3D stretch-bending parts. In order to achieve high-efficiency and high-quality forming of such kind of structural components, the springback behaviors of the AA6082 aluminum profiles are investigated based on the flexible multi-points 3D stretch-bending process (3D FSB). Firstly, a finite element simulation model for the 3D FSB process was developed to analyze the forming procedure and the springback procedure. The forming experiments were carried out for the rectangle-section profile to verify the effectiveness of the simulation model. Secondly, the influence of tension on springback was studied, which include the pre-stretching and the post-stretching. Furthermore, the influences of the bending radius and bending sequence are revealed. The results show that: (1) The numerical model can be used to evaluate the effects of bending radius and process parameters on springback in the 3D FSB process effectively. (2) The pre-stretching has little effect on the horizontal springback reduction, but it plays a prominent role in reducing the springback in the vertical direction. (3) The increase of bending deformation in any direction will lead to an increase of springback in its direction and reduce the springback in the other direction. Besides, it reduces the relative error in both directions simultaneously. This research established a foundation to achieve the precise forming of the 3D stretch-bending parts with closed symmetrical cross-section.


Author(s):  
Daniel Maier ◽  
Sophie Stebner ◽  
Ahmed Ismail ◽  
Michael Dölz ◽  
Boris Lohmann ◽  
...  

2014 ◽  
Vol 620 ◽  
pp. 417-423 ◽  
Author(s):  
Zhong Wen Xing ◽  
Zhi Wei Xu ◽  
Hong Liang Yang ◽  
Cheng Xi Lei

A finite element model of high-strength rectangular section steel tube in rotary-draw bending is established to study the stress and strain in the bending process. Based on control variate method, this paper analyzes the influence laws of three geometric parameters on rotary-draw bending. The results show that bending radius is the most important factor, forming property increases significantly with the increase of bending radius, the trends of cracking and wrinkling are all decreased. The thickness of wall has influence on the strain of inwall, thinner tube may cause crack and wrinkle. Fillet radius has no effect on ektexine, the strain of inwall decreases slightly with the increase of fillet radius.


2021 ◽  
Author(s):  
Matias Alonso ◽  
Jean Vaunat ◽  
Minh-Ngoc Vu ◽  
Antonio Gens

<p>Argillaceous rocks have great potential as possible geological host medium to store radioactive waste.  Andra is leading the design of a deep geological nuclear waste repository to be located in the Callovo-Oxfordian formation. In the framework of this project, excavations of large diameter galleries are contemplated to access and to store intermediate-level long-lived nuclear waste at repository main level. The closure of the repository will be realized by building sealing structures of expansive material.</p><p>The response of such structures is affected by several thermo-hydro-mechanical coupled processes taking place in the near and far field of the argillaceous formations. They include the formation of an excavation induced damaged zone around the galleries, the impact of the thermal load on host rock pressures and deformations, the long-term interaction with support concrete structural elements and the hydration and swelling of sealing materials. As a result, the study of their performance requires to perform simulation works of increasing complexity in terms of coupling equations, problem geometry and material behaviour. As well, challenging computational aspects, as the ones related to fractures creation and propagation, have to be considered for a representative analysis of the problem.</p><p>This work presents advanced large scale THM numerical models to provide keys about the response of the host rock around large diameter galleries during excavation and further thermal load as well as to analyse the performance of large diameter sealing structures. Particular features of the models include on one hand advanced constitutive laws to capture the development of the fractured zone around excavations, the behaviour of host rock/gallery support interfaces and the multi-scale response of bentonitic backfill. On the other hand, simulations consider geometries including constructive details of interest at decimetre scale within large discretization domain covering the whole formation stratigraphic column.</p><p>These challenging simulations provided qualitative and quantitative results on key aspects for natural and engineered barrier integrity, like extension of the damaged zone, impact of the thermal load and water pressure variations in the surrounding geological layers, duration of natural hydration phase, swelling pressure development and seals global stability.</p>


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