Industrial Welding Research Articles

Dover Corp

AbstractIndustrial Machinery and Equipment (MIC: 11.5 SIC: 3531 NAIC: 333120)Dover is a diversified industrial manufacturing corporation made up of 49 operating companies. Dover Diversified's products include packaging and printing machinery, heat transfer equipment, food refrigeration and display cases as well as products for use in the defense, aerospace and automotive industries. Dover Industries makes products for use in the waste handling, bulk transport, automotive service, commercial food service and packaging, welding, cash dispenser and construction industries. Dover Technologies' products include automated assembly and testing equipment, specialized electronic components and industrial printers. Dover Resources manufactures products for various industries.

A compact vision sensor for weld pool surface sensing

The purpose of vision-based sensing devices in the welding industry is to electronically replicate the role of a skilled welder and emulate the human eye with a light-sensing device such as camera and the human brain with a computer algorithm that interprets the images. Just as an optical feedback from human eye guides the human welder, optical feedback in this electronic system would be used to control a welding process, in the case of this research, the Gas Tungsten Arc Welding (GTAW). Such sensing systems have been developed, but the purpose of this study is to build one using more commonly available elements and on a much smaller scale, as to be able to attach it to an already-existing welding system without imposing dramatic space requirements on the system. This paper discusses the procedure employed in developing the knowledge base and the experimental system used for building this compact sensor. Experiments have been performed to determine the positioning of the lens, its focal length and size. A study of the illuminating system is also documented towards understanding how light is dispersed under the welding environment. The illumination system is based on structured laser light, where a laser line is projected on the weld pool. The weld pool is divided into three parts: front (deepest), middle and back (shallow). Experiments have been performed to determine the position where the laser light needs to hit the weld pool and how it is reflected from various points of the weld pool.

American link pays off for welding and joining industry

American link pays off for welding and joining industry

American link pays off for welding and joining industry

American link pays off for welding and joining industry

Dover Corp

Mergent's Dividend AchieversVolume 3, Issue 3 p. 87-87 U.S. Company Reports Dover Corp† First published: 30 June 2006 https://doi.org/10.1002/div.4313 † Contact: : Thomas L. Reece — Chmn. Address: : 280 Park Avenue, New York, NY 10017 Web Site: : www.dovercorporation.com AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Industrial Machinery and Equipment (MIC: 11.5 SIC: 3531 NAIC:333120) Dover is a diversified industrial manufacturing corporation made up of 49 operating companies. Dover Diversified's products include packaging and printing machinery, heat transfer equipment, food refrigeration and display cases as well as products for use in the defense, aerospace and automotive industries. Dover Industries makes products for use in the waste handling, bulk transport, automotive service, commercial food service and packaging, welding, cash dispenser and construction industries. Dover Technologies' products include automated assembly and testing equipment, specialized electronic components and industrial printers. Dover Resources manufacture products for various industries. Volume3, Issue3Summer 2006Pages 87-87 RelatedInformation

Real-time arc welding defect detection technique by means of plasma spectrum optical analysis

An optimized technique for real-time spectral analysis of thermal plasmas, with application in the monitoring and defect detection of industrial welding processes, particularly arc-welding, is presented in this paper. The calculation of the plasma electronic temperature by means of a sub-pixel algorithm permits on-line quality assessment of the welds, allowing the detection of common defects to be found in the welding seam, such as oxidation due to insufficient shielding gas flux or lack of penetration caused by current fluctuations of the welding power source. The proposed technique has been successfully checked in a real-time arc-welding monitoring system, and experimental results of stainless-steel welds are also reported.

A comparison of different discriminant analysis techniques in a steel industry welding process

The present work compares several statistical discriminant analysis techniques applied to a steel industry welding process. Data from 85 variables collected from 18,605 links, classified as Good (18,381), Defective (195) or Bad (29) from laboratory analysis, are available. Process engineers want to find out which variables explain the main differences between the three defined types, so they can implement effective action to reduce the percentage of Defective and Bad links. The approaches used are SIMCA, Global PCA, PLS-DA and Fisher's Linear Discriminant Analysis (LDA). The dataset comprises two kinds of variables, one for the chemical properties of the links, and the other related to the welding process. All the above approaches basically lead to the same results and match the ones derived from the more traditional Fisher s Linear Discriminant Analysis (LDA) technique. The pros and cons of the approaches used are discussed.

Dover Corp

AbstractIndustrial Machinery and Equipment (MIC: 11.5 SIC: 3531 NAIC: 333120)Dover is a diversified industrial manufacturing corporation made up of 49 operating companies. Dover Diversified's products include packaging and printing machinery, heat transfer equipment, food refrigeration and display cases as well as products for use in the defense, aerospace and automotive industries. Dover Industries makes products for use in the waste handling, bulk transport, automotive service, commercial food service and packaging, welding, cash dispenser and construction industries. Dover Technologies' products include automated assembly and testing equipment, specialized electronic components and industrial printers. Dover Resources manufactures products for various industries.

Determination of GTA and GMA welding arc temperatures

The welding arc has been successfully used in the welding industry for many years. However, not all physical phenomena assciated with it have, as yet, been fully understood and explained. Consequently, there arises a need to investigate the work of the arc during GTA and GMA processing. Models of the welding arc are being constructed with a view to gaining a better insight into the occurring phenomena1–5 including arc temperature since this is the parameter which influences all of the changes taking place.6 Investigations into the welding arc temperature lead to a better understanding of its working, The temperature of the welding arc varies from 5 000 to 30 000 K depending on the welding parameters and the type of shielding gas. After the introduction into the arc's plasma of easily ionized atoms of sodium or potassium, a maximum temperature of the order of 6 000 K can be reached.7

Dover Corp.

AbstractIndustrial Machinery and Equipment (MIC: 11.5 SIC: 3531 NAIC:333120)Dover is a diversified industrial manufacturing corporation made up of 52 operating companies. Dover Diversified's products include packaging and printing machinery, heat transfer equipment, food refrigeration and display cases as well as products for use in the defense, aerospace and automotive industries. Dover Industries makes products for use in the waste handling, bulk transport, automotive service, commercial food service and packaging, welding, cash dispenser and construction industries. Dover Technologies' products include automated assembly and testing equipment, specialized electronic components and industrial printers. Dover Resources manufactures products for various industries.

Reduced Pressure Electron Beam Welding in the Power Generation Industry

[in Japanese]

Dover Corp.

Mergent's Dividend AchieversVolume 2, Issue 2 p. 83-83 U.S. Company Report Dover Corp.† First published: 22 April 2005 https://doi.org/10.1002/div.2254 † Contact: : Thomas L. Reece — Chmn. Address: : 280 Park Avenue, New York, NY 10017 Web Site: : www.dovercorporation.com AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Industrial Machinery and Equipment (MIC: 11.5 SIC: 531 NAIC: 33120) Dover is a diversified industrial manufacturing corporation made up of 52 operating companies. Dover Diversified's products include packaging and printing machinery, heat transfer equipment, food refrigeration and display cases as well as products for use in the defense, aerospace and automotive industries. Dover Industries makes products for use in the waste handling, bulk transport, automotive service, commercial food service and packaging, welding, cash dispenser and construction industries. Dover Technologies' products include automated assembly and testing equipment, specialized electronic components and industrial printers. Dover Resources manufactures products for various industries. Volume2, Issue2Spring 2005Pages 83-83 RelatedInformation

Finite Element Analysis of Arc-Welding Process by Parallel Computation

2) introduced the method for the analysis of welding processes. The subjects of the FEA (finite element analysis) of arcwelding processes may be categorized into two in general. The first is on the modeling of welding process itself, and it has been already established regarding how to model heat input, what constitutive equation to use, and how to simulate the filling of filler material, etc. The other is on the numerical analysis and the associated techniques for the fast solution of the threedimensional FEA for welding process, for the three-dimensional FEA of welding process requires an enormously great deal of computing time and computer memory. Three-dimensional FEA of welding process, which particularly includes heat transfer, metallurgical phase transformation and transformation plasticity, needs a huge amount of computation time and, then it limits practical applications of the method for industrial welding problems. Application of parallel computation is a general alternative to reduce the computation time without any loss of accuracy of the results. In this paper, we explore on the effectiveness of the application of parallel computation for arc welding problems. The outline of the paper is as follows. Firstly, a brief review of finite element formulation for arc-welding process is given in Section 2, and the implementation of a parallel frontal solver developed for FEA of arc-welding process is given in Section 3. In Section 4, a numerical test for butt-welding process is provided to demonstrate the effectiveness of parallel computation.

A model for evaluation of laser welding efficiency and quality using an artificial neural network and fuzzy logic

For any welding process, efficiency and quality strongly depend on the energy input, which is the energy introduced per unit length of weld from a travelling heat source. The focused laser beam is one of the highest power density sources available to the welding industry today, which makes it possible to weld with very low energy input with respect to most of other welding processes. In this paper a number of stainless steel butt joints were produced by laser irradiation. The welding efficiencies were calculated as the melted volume-energy input ratio. Moreover, the weld crown and depth were measured in order to evaluate the joint quality. The collected data were interpolated and correlated to the process parameters using an artificial neural network. They were then clustered using a fuzzy C-means algorithm. During the training stage of the neural network algorithm, the design of experiment (DOE) technique was used for the selection of the optimized network parameters. In practice, using some artificial intelligence, a model was built to choose the most suitable laser welding process for producing high efficiency and good quality, and is now available for supporting design and research.

Remediation and Liquid-Liquid Phase Transfer Extraction of Chromium(VI). A Review

Chromium(VI) is a widely used industrial chemical, and is generally considered to pose a greatest human health risk because it is more toxic, more soluble, and more mobile than chromium(III). Workers in industries that use chromium, in particular stainless steel welding, chromate production, chromium plating, and chrome pigment industries, where exposure via inhalation of aerosols is primarily to hexavalent chromium, are at increased risk of chromium effects. In this article we demonstrate various studies regarding remediation methods in particular liquid-liquid extraction of chromate and dichromate anions with various functionalized calixarenes. This review article briefly discusses various molecular designs of calixarene-type macrocycles for chromium(VI) oxoanion recognition, and gives examples on the relationship between structure and selectivity. The article does not, however, attempt to cover all of the different approaches to chromium(VI) extraction. A review with 73 references.

IIW International Welding Congress December 01–03, 2003 Tehran-Iran Economy — Management — Productivity — Standards in the Welding Industry

IIW International Welding Congress December 01–03, 2003 Tehran-Iran Economy — Management — Productivity — Standards in the Welding Industry

A reference architecture for the design of an industrial temperature feedback welding control system

This paper describes a provisional not fully developed architecture of a thermal feedback system for closed-loop control of robotic arc welding. The architecture is based on an off-line planning system for welding and an on-line welding control system, where the off-line planning system builds the reference to be followed by the on-line closed-loop system. The main aim of this architecture is to develop a method by which thermal feedback welding control systems can be designed. This control system is meant for control of welding of thick-walled sheet metal geometries and the system feeds back the temperatures on the surface of the geometry. The temperature is fed back by an infrared CCD-array camera.

IIW International Welding Congress December 01–03, 2003 Tehran-Iran Economy — Management — Productivity — Standards in the Welding Industry

IIW International Welding Congress December 01–03, 2003 Tehran-Iran Economy — Management — Productivity — Standards in the Welding Industry

Residual Stress Distributions in Glass/Metal‐Joints produced by Ultrasonic Torsion Welding

AbstractThe development and industrial application of efficient methods to join glass with metals which combine the individual advantages of both material groups are a great technological challenge. One research field of the Institute of Materials Science and Engineering is the production of glass/metal joints by means of ultrasound. Industrial applications are for example the sealing of glass vessels, fixtures in the vacuum technique or lens mounts. For this reason an industrial ultrasonic torsion welding system normally used for metal weldings was modified to be suitable for the demands of high sensitive glass/metal‐joints. With the developed welding system helium‐tight joints of glass and metals can be realized. In comparison to the conventional welding techniques [1] for glass like diffusion welding or adhesive bonding, ultrasonic torsion welding is characterized by very short welding times (< 1s) as well as low welding temperatures (< 450°C). Further advantages of this joining technique are the high automation potential and the environmental compatibility. Furthermore this technique can be applied under normal or specific atmospherical conditions. In spite of the low joining temperatures thermal residual stresses occur during the cooling of the joints due to the different coefficients of thermal expansion of the used materials [2]. In the present paper the measurement and calculation of the temperature distribution and the development of thermal residual stresses are described.

Cytotoxicity and oxidative mechanisms of different forms of chromium

Chromium exists mostly in two valence states in nature: hexavalent chromium [chromium(VI)] and trivalent chromium [chromium(III)]. Chromium(VI) is commonly used in industrial chrome plating, welding, painting, metal finishes, steel manufacturing, alloy, cast iron and wood treatment, and is a proven toxin, mutagen and carcinogen. The mechanistic cytotoxicity of chromium(VI) is not completely understood, however, a large number of studies demonstrated that chromium(VI) induces oxidative stress, DNA damage, apoptotic cell death and altered gene expression. Conversely, chromium(III) is essential for proper insulin function and is required for normal protein, fat and carbohydrate metabolism, and is acknowledged as a dietary supplement. In this paper, comparative concentration- and time-dependent effects of chromium(VI) and chromium(III) were demonstrated on increased production of reactive oxygen species (ROS) and lipid peroxidation, enhanced excretion of urinary lipid metabolites, DNA fragmentation and apoptotic cell death in both in vitro and in vivo models. Chromium(VI) demonstrated significantly higher toxicity as compared with chromium(III). To evaluate the role of p53 gene, the dose-dependent effects of chromium(VI) were assessed in female C57BL/6Ntac and p53-deficient C57BL/6TSG p53 mice on enhanced production of ROS, lipid peroxidation and DNA fragmentation in hepatic and brain tissues. Chromium(VI) induced more pronounced oxidative damage in multiple target organs in p53 deficient mice. Comparative studies of chromium(III) picolinate and niacin-bound chromium(III), two popular dietary supplements, reveal that chromium(III) picolinate produces significantly more oxidative stress and DNA damage. Studies have implicated the toxicity of chromium picolinate in renal impairment, skin blisters and pustules, anemia, hemolysis, tissue edema, liver dysfunction; neuronal cell injury, impaired cognitive, perceptual and motor activity; enhanced production of hydroxyl radicals, chromosomal aberration, depletion of antioxidant enzymes, and DNA damage. Recently, chromium picolinate has been shown to be mutagenic and picolinic acid moiety appears to be responsible as studies show that picolinic acid alone is clastogenic. Niacin-bound chromium(III) has been demonstrated to be more bioavailable and efficacious and no toxicity has been reported. In summary, these studies demonstrate that a cascade of cellular events including oxidative stress, genomic DNA damage and modulation of apoptotic regulatory gene p53 are involved in chromium(VI)-induced toxicity and carcinogenesis. The safety of chromium(III) is largely dependent on the ligand, and adequate clinical studies are warranted to demonstrate the safety and efficacy of chromium(III) for human consumption.