scholarly journals An Experimental Investigation of Magnetically Impelled Arc Butt Welding of Pipes: A Review

Author(s):  
Abdul Khadeer Sk ◽  
Naseeb Khan

This paper describes a new development of circumferential welding of pipes. Circumferential butt welds are commonly used to join pipes in various industries, including power plants and automobile industries. Magnetically impelled arc butt welding process is a hybrid welding technique. It uses a rotating electric arc as its heat source and is known as efficient method for pipe welding. In this process heat is evolved prior to forging by an arc generated between two coaxially aligned pipes, this arc rapidly rotates along the circumferential edges of the pipes to be welded due to the electromagnetic force exerted by the interaction of arc current and magnetic field generated by the external magnetic system. The entire weld over the full joint thickness is made in one single operation, instead of using several passes as in conventional welding. The main emphasis of this review is to describe the different works carried out in the past which help full for providing the information for the future development of research work. Present study exposes the different works that has been done in the past for improving the weld quality.

Author(s):  
Deepak Bhandari ◽  
Rahul Chhibber ◽  
Lochan Sharma ◽  
Navneet Arora ◽  
Rajeev Mehta

The bimetallic welds are frequently utilized for pipeline transport system of the nuclear power plants. The occurrences of welding defects generally depend on the filler electrode as well as the electrode coatings during shielded metal arc welding process. This study involves the design of austenitic stainless steel welding electrodes for SS304L–SA516 bimetallic welds. The objective of research work includes the novel design of Al2O3–TiO2–CaO–SiO2 coatings by combining two ternary phase systems using extreme vertices mixture design methodology to analyze the effect of key coating constituents on the weld metal chemistry and mechanical properties of the welds. The significant effect of electrode coating constituent CaO on weld metal manganese content is observed which further improves the toughness of bimetallic weld joints. Various regression models have been developed for the weld responses and multi objective optimisation approach using composite desirability function has been adopted for identifying the optimized set of electrode coating compositions. The role of delta ferrite content in promoting the favourable solidification mode has been studied through microstructural examination.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Krzysztof Wałęsa ◽  
Krzysztof Talaśka ◽  
Dominik Wilczyński ◽  
Jan Górecki ◽  
Dominik Wojtkowiak

AbstractThe paper discusses the topic of butt welding of polyurethane drive belts by the hot plate method in the context of modeling the process of this technological operation. Based on the analysis of the butt welding process, a series of studies of the thermomechanical properties of the material from which the belt is made has been planned. The results will be used for mathematical modeling of the welding process, and in particular its most important phase: the plasticizing operation. On this basis, the study of the compression of cylindrical specimens taken from the belt has been performed at two different speeds. Their result is the relationship between the compressive stress σc and the modulus of longitudinal elasticity Ec at compression and: deformation εc, temperature value T, as well as the compressive velocity vc. In the next step, dynamic viscosity η of the belt material was determined based on the results of dynamic thermomechanical analysis. The research work culminated in the attempts to plasticize the material on a hot plate, in conditions similar to the process of industrial welding. These studies were performed at different speeds vpl, resulting in the correlation between the force required for plasticizing Fpl and the value of the speed of the belt end vpl relative to the hot plate heated to a temperature Tp. The obtained results will be used to formulate a mathematical model of plasticizing the material, based on the selected mechanical deformation models.


2020 ◽  
Vol 25 ◽  
Author(s):  
Bras Senra de Oliveira ◽  
Lino Alberto Soares Rodrigues ◽  
Ednelson Silva Costa ◽  
Eduardo de Magalhães Braga ◽  
Marcos Allan Leite dos Reis

Abstract: This work is distinguished by searching for a non-destructive technology, and X-ray diffraction was validated by the XStress 3000 analyser. Measurements of residual stresses in the welded zone of premium pearlitic rails was performed, rail surface hardness of 370 HB and 0.79% carbon content. The welding of the rails was done by flash butt process, performed by Schlatter GAAS 80 stationary equipment. The results of the tensile and compressive stress measurements identified the residual stresses in the welded zone, with specific zones of tensile stresses misplaced at the weld center, with values up to 391 MPa, and compressive stresses, with values up to -166 MPa, as it moves away rails weld center. An important point of this study is the residual stress measurement considering a complete welding process, including: pre-grinding, flash butt welding, heat treatment, finishing grinding and straightening. Lastly, was observed the welding technique potentially can induce residual stresses at rails.


2014 ◽  
Vol 618 ◽  
pp. 448-452
Author(s):  
Xin Wei Zheng ◽  
Xue Cong Hu ◽  
Zhi Yu Wang ◽  
An Li Miao

The research work, Ascertaining the connection type between evaporating tube bundle and a steam drum shell on a Natural Circulation marine supercharged boiler, is important. For this reason the method, calculating the low-cyle fatigue life of supercharged boiler steam drums put forward by Xin-wei Zheng, et al., was put to use; Based on the relevant basic data from design department and two typical running conditions of one supercharged boiler, the cumulative fatigue damage ratio of welding technique was calculated. The calculated result proves that it exceeds the maximum value of 1.0 and the upper limit value of 0.75 in fossil-fuel power plants, respectively. So welding technique can’t guarantee the low-cycle fatigue life of this steam drum, the only connection type is expanded joint, and the connection type has been put into practice.


2020 ◽  
pp. 133-139
Author(s):  
Sanatan Ratna ◽  
B Kumar

In the past few decades, there has been lot of focus on the issue of sustainability. This has occurred due to the growing concerns related to climate change and the growing awareness about environmental concerns. Also, the competition at global level has led to the search for the most sustainable route in the industries. The current research work deals with the selection of green supplier in a Nickle coating industry based on certain weighted green attributes. For this purpose, a hybrid tool comprising of Fuzzy AHP (Fuzzy Analytical Hierarchy) and VIKOR (VlseKriterijumska Optimizacija I Kompromisno Resenje) is used. The Fuzzy AHP is used for assigning proper weights to the selected criteria for supplier evaluation, while VIKOR is used for final supplier selection based on the weighted criteria. The three criterions for green supplier selection are, Ecological packaging, Corporate socio-environmental responsibility and Staff Training. The outcome of the integrated model may serve as a steppingstone to other SMEs in different sectors for selecting the most suitable supplier for addressing the sustainability issue.


2018 ◽  
Vol 9 (07) ◽  
pp. 20492-20498
Author(s):  
Aborisade Olasunkanmi ◽  
Christopher Agulanna

This work interrogates federal character principle (FCP) in Nigeria. The FCP was designed to fundamentally address the striking features of Nigeria politics of intense struggles for power among the different ethnic groups in the country between the elites from the North and their Southern counterparts and the various segments, but the practice of FCP in Nigeria so far raises curiosity and doubts. Given the outcome of the interrogation, this research work discovered and conclude that federal character has not indeed achieve its objective in the Nigeria, the study finds that Ethnocentrism, Elitism, Mediocrity, Mutual suspicion amongst others accounts for some inhibiting factors of the FCP in Nigeria. Like many other provisions of the Constitution, the Federal Character principle was meant to correct some imbalances experienced in the past, but it has created more problems than it has attempted to solve. Rather than promote national unity, it has disunited Nigerians. There is an urgent need to use more of professionals and result oriented Nigerians to carry out national tasks, than to use unprogressive people due to this "Federal character" issue. Nigeria should be a place where one's track records and qualifications are far greater than just "where they come from" or their lineage if Nigerian truly want to progress.


2020 ◽  
Vol 14 (4) ◽  
pp. 324-369 ◽  
Author(s):  
Rafał Rusiecki ◽  
Jakub Witkowski ◽  
Joanna Jaszczewska-Adamczak

Background: Mouse Double Minute 2 protein (MDM2) is a cellular regulator of p53 tumor suppressor (p53). Inhibition of the interaction between MDM2 and p53 proteins is a promising anticancer therapy. Objective: This updated patent review is an attempt to compile the research and achievements of the various researchers working on small molecule MDM2 inhibitors from 2010 to date. We provide an outlook into the future for therapy based on MDM2 inhibition by presenting an overview of the most relevant patents which have recently appeared in the literature. Methods: Literature and recent patents focusing on the anticancer potential of MDM2-p53 interaction inhibitors and its applications have been analyzed. We put the main emphasis on the most perspective compounds which are or were examined in clinical trials. Results: Literature data indicated that MDM2 inhibitors are therapeutically effective in specific types of cancer or non-cancer diseases. A great number of patents and research work around new MDM2- p53 interaction inhibitors, possible combinations, new indications, clinical regimens in previous years prove that this targeted therapy is in the scope of interest for many business and academic research groups. Conclusion: Novel MDM2 inhibitors thanks to higher potency and better ADME properties have shown effectiveness in preclinical and clinical development however the final improvement of therapeutic potential for MDM2 inhibitors might depend on the useful combination therapy and exploring new cancer and non-cancer indications.


2021 ◽  
pp. 1-11
Author(s):  
P. N. R. L. Chandra Sekhar Author ◽  
T. N. Shankar Author

In the era of digital technology, it becomes easy to share photographs and videos using smartphones and social networking sites to their loved ones. On the other hand, many photo editing tools evolved to make it effortless to alter multimedia content. It makes people accustomed to modifying their photographs or videos either for fun or extracting attention from others. This altering brings a questionable validity and integrity to the kind of multimedia content shared over the internet when used as evidence in Journalism and Court of Law. In multimedia forensics, intense research work is underway over the past two decades to bring trustworthiness to the multimedia content. This paper proposes an efficient way of identifying the manipulated region based on Noise Level inconsistencies of spliced mage. The spliced image segmented into irregular objects and extracts the noise features in both pixel and residual domains. The manipulated region is then exposed based on the cosine similarity of noise levels among pairs of individual objects. The experimental results reveal the effectiveness of the proposed method over other state-of-art methods.


Author(s):  
Khangamlung Kamei ◽  
Muhammad A. Khan

AbstractFatigue damage is a concern in the engineering applications particularly for metal structures. The design phase of a structure considers factors that can prevent or delay the fatigue and fracture failures and increase its working life. This paper compiled some of the past efforts to share the modelling challenges. It provides an overview on the existing research complexities in the area of fatigue and fracture modelling. This paper reviews the previous research work under five prominent challenges: assessing fatigue damage accurately under the vibration-based loads, complications in fatigue and fracture life estimation, intricacy in fatigue crack propagation, quantification of cracks and stochastic response of structure under thermal environment. In the conclusion, the authors have suggested new directions of work that still require comprehensive research efforts to bridge the existing gap in the current academic domain due to the highlighted challenges.


2020 ◽  
Vol 10 (1) ◽  
pp. 674-680
Author(s):  
Piotr Sęk

AbstractThe purpose of the experiment was to study the influence of the laser beam in pulse mode on metallic foils in order to obtain a spot weld. The welding process was carried out using the overlap weld method, using spot welds in various quantities. The Nd - YAG BLS 720 pulsed laser was used to conduct the experiment. The impact of the number of spot welds on the value of force needed to break the sample was examined. A number of measurements were carried out to determine the best process parameters. Butt welding and overlap welding were also performed using a continuous weld consisting of spot welds. Weld strength tests were performed to select the most appropriate parameters for the process under consideration.


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