Showing papers on "Shielded metal arc welding published in 2015"
TL;DR: In this article, a comparative evaluation of mechanical properties and microstructural features of shielded metal arc, gas metal arc and friction stir welded (FSW) naval grade HSLA steel joints was carried out.
158 citations
TL;DR: In this paper, a keyhole gas tungsten arc welding (K-TIG) was used to weld AISI 316L stainless steel of mid-thickness.
112 citations
TL;DR: An attempt is made to correlate arc sound with the weld quality in one of the major joining processes employed in fabrication industry, especially one that manufactures boiler, pressure vessels, marine structure etc.
96 citations
TL;DR: In this paper, the effect of oxide fluxes on weld morphology, arc voltage obtained with A-TIG welding, which applied to the welding of 6mm thick modified 9Cr-1Mo steel plates.
86 citations
TL;DR: In this article, a finite element method (FEM) incorporating the cast microstructure and alloy chemical composition was used to calculate the welding stresses and predict crack initiation, and a pre-welding homogenization heat treatment, lower welding heat input, and post welding crater grinding of each individual welding seam can decrease its hot cracking susceptibility.
77 citations
TL;DR: In this article, the authors evaluated possible social and environmental impacts of the state-of-the-art welding technologies, such as Manual Metal Arc Welding (MMAW), Manual Gas Metal Arc Weigeling (GMAW) and Automatic Laser-Arc Hybrid Weiging (LAHW), and concluded that the manual processes bring much higher potential risk of welders' health than the automatic processes, especially MMAW.
72 citations
TL;DR: In this paper, a comparative evaluation of an appropriate welding process and welding consumable is based on microstructural features, micro-hardness variation, tensile testing and fracture morphology.
67 citations
TL;DR: In this article, the possible mechanisms of the pores formation and their mitigation during the hybrid laser/arc welding (HLAW) of Advanced High Strength Steel (AHSS) were investigated.
64 citations
TL;DR: In this paper, the effect of coating density of activating flux on the weld pool shape and oxygen content in the weld after the welding process was studied systematically, and the maximum depth/width ratio of stainless steel activated TIG weld was obtained when the coating density was 2.6, 1.3, 2, and 7.8 µm2 for SiO2, TiO2 and Cr2O3, respectively.
Abstract: The use of activating flux in TIG welding process is one of the most notable techniques which are developed recently. This technique, known as A-TIG welding, increases the penetration depth and improves the productivity of the TIG welding. In the present study, four oxide fluxes (SiO2, TiO2, Cr2O3, and CaO) were used to investigate the effect of activating flux on the depth/width ratio and mechanical property of 316L austenitic stainless steel. The effect of coating density of activating flux on the weld pool shape and oxygen content in the weld after the welding process was studied systematically. Experimental results indicated that the maximum depth/width ratio of stainless steel activated TIG weld was obtained when the coating density was 2.6, 1.3, 2, and 7.8 mg/cm2 for SiO2, TiO2, Cr2O3, and CaO, respectively. The certain range of oxygen content dissolved in the weld, led to a significant increase in the penetration capability of TIG welds. TIG welding with active fluxes can increase the delta-ferrite content and improves the mechanical strength of the welded joint.
63 citations
TL;DR: In this paper, the possibility of suppressing microsegregation in weldments by resorting to current pulse was investigated, and the results showed that the joints fabricated with pulsed current gave rise to narrower welds with practically no heat affected zone, a refined microstructure in the fusion zone, reduced micro-segregation, and superior combination of mechanical properties.
Abstract: Superalloy C-276 is known to be prone to hot cracking during fusion welding by Gas Tungsten Arc method. Microsegregation occurring during cooling of fusion zone with consequent appearance of topologically close-packed phases P and µ has been held responsible for the observed hot cracking. The present work investigated the possibility of suppressing the microsegregation in weldments by resorting to current pulse. Weldments were made by continuous current gas tungsten arc welding and pulsed current gas tungsten arc welding using ERNiCrMo-4 filler wire. The weld joints were studied with respect to microstructure, microsegregation, and mechanical properties. Optical microscopy and scanning electron microscopy were employed to study the microstructure. Energy-Dispersive X-ray Spectroscopy was carried out to evaluate the extent of microsegregation. Tensile testing was carried out to determine the strength and ductility. The results show that the joints fabricated with pulsed current gave rise to narrower welds with practically no heat affected zone, a refined microstructure in the fusion zone, reduced microsegregation, and superior combination of mechanical properties.
58 citations
TL;DR: In this article, Nitrogen loss from laser welding melts pools and can have a deleterious effect on weld toughness for duplex stainless steels This effect can be alleviated by using nitrogen as the shielding gas during laser welding.
TL;DR: In this article, the effect of heat input on the mechanical properties of low-carbon steel was studied using two welding processes: Oxy-Acetylene Welding (OAW) and Shielded Metal Arc Welding(SMAW).
Abstract: In this work, the effect of heat input on the mechanical properties of low-carbon steel was studied using two welding processes: Oxy-Acetylene Welding (OAW) and Shielded Metal Arc Welding (SMAW). Two different edge preparations on a specific size, 10-mm thick low-carbon steel, with the following welding parameters: dual welding voltage of 100 V and 220 V, various welding currents at 100, 120, and 150 Amperes and different mild steel electrode gauges of 10 and 12 were investigated. The tensile strength, hardness and impact strength of the welded joint were carried out and it was discovered that the tensile strength and hardness reduce with the increase in heat input into the weld. However, the impact strength of the weldment increases with the increase in heat input. Besides it was also discovered that V-grooved edge preparation has better mechanical properties as compared with straight edge preparation under the same conditions. Microstructural examinations conducted revealed that the cooling rate in different media has significant effect on the microstructure of the weldment. Pearlite and ferrite were observed in the microstructure, but the proportion of ferrite to pearlite varied under different conditions.
TL;DR: In this paper, the authors applied the Life Cycle Assessment (LCA) to evaluate environmental impacts of state-of-the-art welding technologies such as Manual Metal Arc Welding, Laser Arc-Hybrid Welding (LAHW), and two Gas Metal Arc welding (GMAW) variants to join a plate of 20mm thick structural steel.
TL;DR: The microstructure of weld joint in X70 line pipe steel resulted from shielded metal arc welding with E6010 cellulosic electrodes is characterized using optical and electron microscopy as discussed by the authors.
TL;DR: In this article, the feasibility and microstructures of pure copper claddings produced on a pressure vessel A516 Gr. 70 steel plate, using friction stir welding versus gas metal arc welding, were compared.
TL;DR: In this article, the microstructure comparison of Al-Mg-Mn alloy and Al-Zn-mg-mn alloy welded joints reveals that a huge amount of fine equiaxed grains are formed in the weld zone of Zr and Er micro-alloying Al−Mg−Mn welding wire and a great number of precipitation strengthening phases are precipitated in the welding zone after the heat treatment of welded joint in the entirety.
TL;DR: In this paper, Tungsten Inert Gas (TIG) welding process was used to obtain the optimum joint characteristics and minimize defects that will contribute to make the welding process more cost effective.
TL;DR: In this paper, the welding process using 100% CO2 gas was characterized by a large number of spatters, while the penetration depth of a weld was increased and porosity was reduced.
TL;DR: In this paper, the hybrid laser/arc welding (HLAW) was applied to join aluminum alloy (AA6061) to an advanced high strength steel (AHSS) where an explosively welded transition joint, TRICLAD®, was used as an intermediate structural insert between the thick plates of the aluminum alloy and AHSS.
TL;DR: In this article, the welding process is represented in the form of mathematical models developed using response surface methodology and the models were then used to predict the weld bead characteristics with reasonable accuracy.
TL;DR: In this article, the authors report the user experience of AR technology in welding education for future studies and applications, and suggest further studies in order to compare the performance index of learning in simulated welding environment when associated with a previous training perception of AR.
TL;DR: Based on the difference in melting point between aluminum alloy and steel, metal inert gas (MIG) arc brazing-fusion welding process was developed to join thin 6013 aluminum alloy plate to galvanized steel plate as discussed by the authors.
Abstract: Based on the difference in melting point between aluminum alloy and steel, metal inert gas (MIG) arc brazing-fusion welding process was developed to join thin 6013 aluminum alloy plate to galvanized steel plate. A finite element model for lap joint was established to study its thermal process. In modeling, MIG arc was treated as the double ellipse Gaussian plane heat source and the overheated metal droplet was considered as the uniform body heat source. The effects of the zinc coating and the overlap gap were taken into consideration. The brazed seam width and the width of heat-affected zinc coating on the back side of galvanized steel plate were used to validate the calculated results. The results show that the calculated results are in good agreement with experimental results. The calculation results indicate that the temperature is not uniformly distributed in the brazing-fusion welded joint. There is a great difference in the reaction temperature and time at different positions on the brazed interface. In order to satisfy the energy condition in which aluminum plate is fully penetrated and steel plate is not melted, a corresponding relationship that the welding current and welding speed are synchronized to be increased must be followed.
TL;DR: In this article, the influence of hybrid laser-arc welding parameters on the microstructure and mechanical properties of the weld was investigated, namely, influence of welding speed and preheating temperature on the cooling rates, microstructures and hardness.
TL;DR: In this paper, residual stress measurements were performed on DMR-249A steel weld joints fabricated by SMAW and activated flux gas tungsten arc welding (A-GTAW) by X-ray diffraction (XRD) and ultrasonic methods.
TL;DR: In this paper, a high speed tandem gas tungsten arc welding process involving an assistant arc following the main arc to suppress the formation of undercut and humping defects is proposed.
TL;DR: In this article, a finite element model was developed to investigate the thermal process of large spot laser + MIG arc brazing-fusion welding, where the laser was treated as a Gaussian plane heat source, the arc distortion was taken into consideration and the overheated droplet was treated by a uniform body heat source.
TL;DR: In this article, Al-Si-coated hot-press-forming steel sheets were subjected to laser butt welding for making tailor-welded blanks (TWBs).
Abstract: Tailor-welded blanks (TWBs) are made of sheets with various strengths or thicknesses that ensure increased material strength without significantly increasing the weight. In this study, Al-Si-coated hot-press-forming steel sheets were subjected to laser butt welding for making TWBs. After laser welding, the welded blanks were heated and subsequently quenched to simulate a thermal cycle in the hot-press-forming process, and the properties of the welded joints were examined. Arc pretreatment was applied before laser welding, and its influence on the mechanical and metallurgical properties of the welds was analysed.
TL;DR: In this paper, the effect of arc current on the weld interface is also detailed and is found to be defect free at higher values of arc currents, while the results reveal that MIAB welded samples exhibits good structural property correlation for high pressure applications with an added benefit of enhanced productivity at lower cost.
01 Jan 2015
TL;DR: In this paper, a finite element analysis of residual stresses in butt welding of two similar carbon steel plates is performed with the ANSYS software, which includes a model for the thermal and mechanical welding simulation.
Abstract: In this paper, Manual Metal Arc Welding of carbon steel plates was studied. The finite element analysis of residual stresses in butt welding of two similar plates is performed with the ANSYS software. This analysis includes a finite element model for the thermal and mechanical welding simulation. It also includes a moving heat source, material deposit, temperature dependent material properties, metal plasticity and elasticity, transient heat transfer and mechanical analysis. The welding simulation was considered as a sequential coupled thermo-mechanical analysis and the element birth and death technique was employed for the simulation of filler metal deposition. The residual stress distribution and magnitude in the axial direction is to be obtained. A good agreement between the computation and experimental results is to be obtained.
TL;DR: In this article, the impact toughness of the weldments was assessed at both subzero and ambient temperatures, and the weld microstructure was composed of Widmanstatten austenite and a ferrite matrix at the duplex-austenitic weldment.