Arc Welding Equipment Research Articles

Kalibrasi Wire Feeder Flux Core Arc Welding (FCAW) Mengacu Pada Standar British Standard (BS) 7570:2000 Dan British Standard (BS) European Standard (EN) 50504:2008

In the fabrication industry, the welding process plays a crucial role in both engineering and repair production processes. Continuous use of welding machines can lead to a decline in their effectiveness. Suboptimal machines may produce low-quality products. A common issue encountered is the poor quality of welds, even when each step has been aligned with the Welding Procedure Specification (WPS). One source of this problem is the welding equipment itself. The objective of this study is to calibrate arc welding equipment to ensure it remains within machine standards. Calibration is performed in accordance with BS EN 50504:2008 and BS 7570:2000. The calibration focuses on measuring constant voltage and wire feed speed (WFS). The measurement results for WFS variation indicate that it does not exceed a 10% error margin. This suggests that the WFS complies with the established standards. Consequently, the Lincoln LN-25X wire feeder speed is ready for use in fabrication and production processes.

Nichrome Dependency in Welding Layer Using In situ Fabrication on Hardness and Corrosion Properties

The use of shielded metal arc welding (SMAW) equipment to synthesize alloys is one of the most promising methods as it can be used for in-situ fabrication. The hardness and corrosion properties of the deposited layer during the welding process can be enhanced by dilution of nichrome (NiCr) during the process. Therefore, the alloy was synthesized on the surface of the mild steel using SMAW equipment with various NiCr additions. The properties of the alloy were investigated using an X-ray diffraction (XRD), an Optical microscope, a Potentiostat, and a Vickers hardness apparatus. The appearance of martensite overlaps with the ferrite phase could be affected by the addition of NiCr to the alloy. An increase in NiCr content is followed by an increase in the lattice parameter value of the ferrite phase. The presence of a certain amount of nickel (Ni) contributes to the formation of lower transformation phases, including martensite. At the same time, the incorporation of chromium (Cr) also plays a significant role in promoting the formation of acicular ferrite. An increase in NiCr content in NiCr2 and NiCr3 samples results in a quantitative increase in martensite formation. Adding 0.434 g of NiCr to the weld deposited layer could result in the corrosion rate of the alloy being 0.1118 mm/y. Higher hardness is found in the NiCr3 sample, around 742.06 HV.

EQUIPMENT FOR MECHANISING THE SUBMERGED ARC WELDING PROCESS

Flux welding is a notable, reliable, and adaptable method of combining metals among other welding techniques. Flux welding is an arc welding technique that employs a substance known as "flux" to shield the weld pool from any chemical reactions with atmospheric constituents while welding. Flux materials often comprise borax, hydrochloric acid, or zinc chloride. In the process of flux welding, a joint is covered with a layer of flux, or alternatively, a flux-coated or flux-cored electrode is employed. Upon the formation of the weld pool, the flux undergoes melting and adheres to the pool, thus safeguarding it against any potential reaction with air constituents. This manuscript describes equipment used in mechanized flux welding process in order to improve its performance. Lincoln Electric NA-3N submerged arc welding equipment on a universal lathe longitudinal carriage was designed. The equipment was mounted on a carriage with a maximum longitudinal travel of 2380 mm and a maximum transverse stroke of 410 mm. This carriage moves the welding equipment. The longitudinal advance allows longitudinal and transverse welding on this system.

Determining patterns in the generation of magnetic fields when using different arc welding techniques

This paper reports a study into the levels of magnetic fields induced by arc welding equipment in various ways in order to assess their impact on the body of welders. It is known that welders are exposed to a magnetic field of high intensity. Depending on the welding technique and the type of welding equipment, it may exceed the maximum permissible levels (MPL). Note that new Ukrainian sanitary standards for magnetic fields have been introduced, which regulate their levels depending on the frequency range. Therefore, it became necessary to carry out their hygienic assessment according to the new standards in order to devise appropriate methods for protecting welders. To this end, it was required to choose a new generation of devices to determine the intensity of magnetic fields induced by welding equipment. Based on the analysis of the constructed oscillograms and spectrograms of magnetic fields, it was found that semi-automatic welding with a metal electrode in carbon dioxide is characterized by an increased level of magnetic field in the frequency range of 50‒1000 Hz. With automatic arc welding under the flux, there are no excess of the maximum permissible levels of individual harmonics of the magnetic field but there is an excess of the total value of all harmonic components of the magnetic field. Manual arc welding with direct current involving a non-melting electrode in argon is characterized by a moderate level of magnetic field in workplace. During manual arc welding with coated electrodes, the exceeded level of the magnetic field is observed only on the electrode cable itself. It is shown that the spectral composition of the magnetic field signal is determined mainly by the welding technique itself, the peculiarities of arc combustion, and the nature of the transfer of electrode metal in the arc gap, as well as the initial parameters of the power supplies of the welding arc

On the solution of the problem of synthesis of the control system for the process of dosed feed of electrode wire for arc welding equipment

Goal. Refinement of the methodology for the development of an effective control system for an electric drive with controlled relay-type regulators for organizing a metered feed of an electrode wire using the parameters of the arc process with the possibility of using it in design practice and practice of technological application. Methodology. The proposed method for the mathematical description (mathematical model) of the system of the developed structure electric drive - arc process with current feedback of welding with a variable structure device is based on the theory of automatic control as applied to nonlinear elements, the application of the theory of operational calculus. At the same time, a selection and description of a nonlinear node in the feedback circuit in the form of a relay element with a certain structure and subsequent linearization of this element was made. As an electric motor of the electrode wire feeder, a new development of a specialized valve electric motor is used, which is used in the system with a microprocessor controller. Results. Due to the presence of a substantially nonlinear link, the calculation of the valve electric drive system – the arc process can be found on the basis of a system of nonlinear differential equations, which is practically impossible for practical application. In this work, these complications are overcome on the basis of a rational choice of the description of the nonlinear link, its harmonic linearization and obtaining on this basis a mathematical description of the system, from which, using the methodology of operational calculus, the relations necessary for calculating the parameters of the system are determined in analytical form. Originality. The problem of calculating a rather complex problem of mathematical description of the valve electric drive system – a technological link in the form of an arc process with a substantially nonlinear link in the feedback circuit in the work is solved with the effective use of a set of methodological methods, which include as a means of representing individual links, including nonlinear links selected simplifications and solutions of the obtained differential equations using original methods of operational calculus. The proposed method (mathematical model) is tested in two directions – oscillography of a real system, as well as system simulation. Practical significance. Using the developed methods for describing the control system, it is possible to calculate its characteristics and, on their basis, select the parameters for setting the electric drive controller, which allows, without additional experimental research, to obtain the necessary character of the transfer of electrode metal, and, consequently, the quality of the result of the arc process.

Investigation on present labour accidents due to electric shock and comparison of safety devices for preventing electric shock accidents used for arc welding equipment in foreign countries

休業4日以上の感電に起因する労働災害を厚生労働省の労働災害（死亡・休業4日以上）データベースを用いて平成18～27年の10年間を分析した結果，定性的な状況は平成10年以前と感電災害の多く発生している業種，発生月，感電災害を誘引した起因物などに変化の無いことを明らかにした．

Microstructure evolution and mechanical properties of titanium matrix composites and Ni-based superalloy joints with Cu interlayer

This study investigated the joining of TiBw/Ti6Al4V composites and Inconel 718 alloy with Cu interlayer using gas tungsten arc welding (GTAW) equipment in order to modify the joints strength. Microstructure analysis indicated that Ti-Cu intermetallic compounds (IMCs) and a small number of Ti-Ni-Cu compounds were generated in the reaction layer with low heat input. While the main products changed into Ti-Ni-Cu compounds, also combined with Ti-Ni compounds and a few ternary compounds with the increase of heat input. Accordingly, the shear strength of dissimilar joints firstly increased and then decreased with the increase of welding current or the decrease of welding speed. The maximum shear strength (370 MPa) was obtained with the current of 100 A and the speed of 110 mm min−1. Moreover, the hardness of reaction layer was much higher than that of parent materials due to the formation of IMCs, and medium heat input can reduce the hardness mismatch in joints.

Orbital Hybrid Laser-arc Welding Using a High-power Fibre Laser for Pipeline Construction

Recently developed fibre lasers provide multi-kilowatt beam power with high quality at impressive energy efficiency. Combined with gas metal arc welding (GMAW) equipment these lasers can be used in a hybrid process to weld thick-walled constructions single-pass, that are currently welded using multi-pass techniques. The main benefits are a reduction of heat induced distortions, due to the low heat input, as well as savings in filler material and process time. Probable applications can be found in power generation, ship building and pipeline constructions. An orbital (girth) laser-hybrid process using a 20 kW fibre laser and a GMAW torch is currently examined at the BAM, Berlin. The aim of this research is to obtain a stable and crack free girth welding process and to demonstrate its application in pipeline construction. The experiments are carried out on 16 mm thick plates as well pipe rings with 36 (914 mm) pipe diameter of X65. Particular welding parameters, such as welding speed, GMAW power, arc length are varied and their influence on the appearance of the weld in the different welding positions is analyzed. Even though issues remain that demand further research it could already be shown that the rings can be welded using a girth hybrid process that is divided into two half girth processes in downward direction.

Arc Welding Processes: An Electrical Safety Analysis

Manual metal arc welding can be a hazardous practice if proper precautions are not taken. The welding procedure uses an open electric arc between an electrode and the metals to be joined. Besides the obvious risks of burns and inflammation of the cornea, which are prevented by using proper personal protective equipment, the operator may also be subject to the risk of electric shock from the exposed parts of the welding circuit, both the electrode and the workpiece. In addition, the welding current, by straying from the intended path, can cause localized heating of parts, with the risks of triggering fires and/or explosive atmospheres. Because of the high current required by the arc welding equipment, operators are exposed also to strong electromagnetic fields. This paper seeks to clarify the aforementioned issues, especially in light of the fact that the risk associated with electric shocks may be unknown to welders and their supervisors.

Experimental investigation and numerical simulation of weld bead geometry and temperature distribution during plasma arc welding of thin Ti-6Al-4V sheets

Numerical and experimental investigations of autogenous plasma arc welding of thin titanium alloy of 2 mm thick and modelling the temperature distribution for predicting the weld bead geometry are presented. The finite element code COMSOL Multiphysics is employed to perform non-linear unsteady heat transfer analysis using parabolic Gaussian heat source. Temperature-dependent material properties such as thermal conductivity, density and specific heat are used to enhance the efficiency of simulation process. A forced convective heat transfer coefficient was used to account for the effect of convection. The experimental trials were conducted by varying the welding speed and current using Fronius plasma arc welding equipment. The simulation results are in good agreement with the experimental results.

A novel inverter twin wires high effect submerged arc welding equipment for steel plate welding

A novel inverter twin wires high effect submerged arc welding equipment for steel plate welding

Formation of smooth transient processes in drives of electric welding equipment

The universal functions of the SH class are used for developing a new universal method of the formation of smooth transient processes in the drives of electric welding equipment with matching of the conditions (start, acceleration, braking, reversal, constancy and arrest). The efficiency of the method is confirmed by the results of mathematical modelling carried out for a direct current drive regardless of excitation in the problem of controlling the feed rate in automatic and semi-automatic arc welding equipment.

Double-electrode arc welding process: Principle, variants, control and developments

Double-electrode gas metal arc welding (DE-GMAW) is a novel welding process in which a second electrode, non-consumable or consumable, is added to bypass part of the wire current. The bypass current reduces the heat input in non-consumable DE-GMAW or increases the deposition rate in consumable DE-GMAW. The fixed correlation of the heat input with the deposition in conventional GMAW and its variants is thus changed and becomes controllable. At the University of Kentucky, DE-GMAW has been tested/developed by adding a plasma arc welding torch, a GTAW (gas tungsten arc welding) torch, a pair of GTAW torches, and a GMAW torch. Steels and aluminum alloys are welded and the system is powered by one or multiple power supplies with appropriate control methods. The metal transfer has been studied at the University of Kentucky and Shandong University resulting in the desirable spray transfer be obtained with less than 100A base current for 1.2mm diameter steel wire. At Lanzhou University of Technology, pulsed DE-GMAW has been successfully developed to join aluminum/magnesium to steel. At the Adaptive Intelligent Systems LLC, DE-GMAW principle has been applied to the submerged arc welding (SAW) and the embedded control systems needed for industrial applications have been developed. The DE-SAW resulted in 1/3 reduction in heat input for a shipbuilding application and the weld penetration depth was successfully feedback controlled. In addition, the bypass concept is extended to the GTAW resulting in the arcing-wire GTAW which adds a second arc established between the tungsten and filler to the existing gas tungsten arc. The DE-GMAW is extended to double-electrode arc welding (DE-AW) where the main electrode may not necessarily to be consumable. Recently, the Beijing University of Technology systematically studied the metal transfer in the arcing-wire GTAW and found that the desired metal transfer modes may always be obtained from the given wire feed speed by adjusting the wire current and wire position/orientation appropriately. A variety of DE-AW processes are thus available to suit for different applications, using existing arc welding equipment.

Pacemakers patients perception of daily life activities and follow-up: a French survey

Introduction: The aim of our study was to assess patients' knowledge about pacemakers after the implantation. Material and methods: We performed a multicenter survey in 13 French centers from January 2011 to July 2012. In each center, patients received usual informations about pacemaker implantation, functioning, and about their habits after the implantation. They signed a consent for implantation. One to 10 days after implantation, all patients received a questionnaire. The questionnaire evaluates patients' perceptions of information and consent, risks of implantation, follow up, and about performing various routine activities (daily life activities, use of electrical devices, ability to undergo medical imaging tests). Results: We included 258 patients. The mean age was 75.6 + 10.6 years 34-102 yrs) and 61% were men. The intervention was a primary implantation in 89% of patients. We noted that 78% on the patients remember that they have signed a consent and 73% of patients remember that they received counselling in the peri-operative period. A considerable proportion of patients considered many routine activities unsafe including driving automobiles (30%), swimming (39%), passing through metal detectors (47%), sleeping on the side of the pacemaker (42%). Also, 28% of patients think they can use induction hobs and 18% think they can use arc welding equipment. Regarding medical imaging, 45%; 29% and 33% of patients considered unsafe making scanners, radiography and echography respectively; and 41% ignored if they can have MRI. Finally, regarding the medical follow up, 11% of patients think they don't need heart medications and 17% of patients think they are exempt from monitoring by a cardiologist. Conclusion: The results of our study highlight on patients' misperceptions on pacemaker functioning and the need in improving practices to better inform patients. Thus, the quality of life of implanted patients may be improved.

185: Pacemaker patients’ perception of daily life activities and medical follow-up: a french survey

We carried out a multicenter survey in 8 French centers. Each patient received a questionnaire to evaluate his perceptions on information and consent, risks associated with pacemaker implantation and ability to perform various routine activities. We included 185 patients. The mean age was 75.4 + 10.5 years. A large number of patients considered many routine activities as unsafe, such as sleeping on the side of the pacemaker (12%), swimming (15%), driving automobiles (17%) and passing through metal detectors (47%). Patients had also misconceptions about using induction hobs (38%) and arc welding equipment (32%). As regards medical imaging, 38% did not know if they could undergo MRI exams. As regards medical follow up, 11% of patients thought they did not need heart medications and 17% that they were exempt from monitoring by a cardiologist. In univariate analysis, the factors associated to misconceptions about pacemakers were an age above 75 years and a primary implantation. The results of our study highlight patients’ misperceptions on life with a pacemaker. This should lead cardiologists to better inform patients at the time of pacemaker implantation.

소방배관용 강관을 위한 반자동 가스메탈아크용접장치 개발과 용접부 특성평가

본 연구에서는 소방배관용 아연도금 강관을 용접하기 위하여 반자동 가스메탈아크용접장치를 개발하고 최적 용접 조건을 확립하고 용접성을 조사하기 위해 보호가스, 전압을 변화시켜 용접시험을 수행하였다. Ar 가스에 <TEX>$O_2$</TEX>를 첨가함으로써 미려한 비드외관과 기공률이 감소되었다. 반자동 용접부는 기계적 강도와 용접이음효율이 수동용접부에 비해 약 1.8배 우수하였으며 수압시험에 의해 건전성이 확인되었다. 본 연구에서 개발된 반자동용접장치로 비숙련자도 강관용접이 가능하며 용접결함이 적고 용접생산성을 증대시킬 수 있을 것으로 기대된다. The semi-automatic gas metal arc welding equipment was developed and the weldability of zinc coated steel pipes was evaluated in terms of strength, porosity and welding parameters including shielding gas composition. The good bead appearance and the reduction of porosity in the welds could be possibly obtained by adding <TEX>$O_2$</TEX> to Ar. The strength and joint efficiency of welds made by the semi-automatic welding equipment was about 1.8 times higher compared with welds manually made. The integrity of welds was confirmed by the water pressure test as well, Finally, it is expected that the weld productivity will be enhanced even unskilled welders can produce quality welds by operating the semi-automatic welding equipment.

SiC Mosfets with Schottky power diodes help optimise the design of multi-functional arc welding equipment in popular power range

Logistics, welder’s comfort, productivity and quality need of weld joint and jobs in hand at site etc., together decide the required arc (constant current (CC) or constant voltage (CV) or their combination) characteristics. Multi-functional arc welding equipment meets such needs. High across the load efficiency, fast settling time of output variables and light and compactness are major pre-requisites of arc welding equipment. Some of them are achieved if switching frequency of inverter is kept high. Constraint of efficiency at high switching frequency is, generally, overcome by adopting proper soft switching topology. This paper suggests that better design is possible for narrow power range arc welding equipment (3–20 kW) using traditional hard-switched inverter with just optimisation in input materials. Reduced component count and reduced interconnections between sub-assemblies in hard-switched full-bridge inverter generate superior design for manufacturability issues.

アーク溶接機器の開発動向

In the field of arc welding equipments, digital control technology has been adopted by employing high performance microprocessors to improve the controllability, and inverter-controlled main circuit has rapidly been innovated in high speed control. This paper describes the trends in the developments in arc welding equipment. For welding power sources, a new output waveform control method combined with digital inverter technology, has been proposed to improve the performance of arc welding process.

Horizontal Submerged Arc Welding Equipment Based on the Torch Swinging Design

In this paper, the transverse cross submerged arc welding process, welding work characteristics and shortcomings encountered was proposed based on PLC, MMI, servo drive system torch swing mechanism. The test debug, and field applications, the effect is very good.

Characteristics of transition processes in production processes in engineering

The class SH functions were used to develop a new method of the formation of smooth transition processes in the production processes in engineering in conditions such as starting up, acceleration, deceleration, reversing, constant running, and shutdown. The efficiency of the method is confirmed by the results of mathematical simulation carried out for DC drives with independent excitation in the task of controlling the feed rate in automatic and semiautomatic arc welding equipment.