scholarly journals Impact of Electromagnetic Stirring on the Gas Metal Arc Welding of an MAR-M247 Superalloy

2021 ◽  
Author(s):  
Yu-Chih Tzeng ◽  
Cheng-Yu Lu ◽  
RenYu Chen
Keyword(s):  
Crack Resistance ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Weld Bead ◽  
Electromagnetic Stirring ◽  
Metal Arc Welding ◽  
Hole Defects ◽  
The Impact

Abstract In this paper, the impact of electromagnetic stirring (EMS) on the gas metal arc welding (GATW) of an MAR-M247 superalloy was investigated. Results revealed that, without electromagnetic stirring, it was easy for carbides in the heat-affected zone (HAZ) of the weld bead to liquefy during welding, leading to weld bead cracks. Electromagnetic stirring refined the grains in the HAZ and the weld bead, leading to grain strengthening and subsequently resulting in the effective improvement in the hardness of the weld bead. In addition, electromagnetic stirring significantly facilitated the formation of the weld bead by the removal of large inclusions which in turn effectively improved crack resistance at the joint. It also accelerated the floating up of gas holes thereby reducing the generation of gas hole defects.

scholarly journals The influence of manual metal arc multiple repair welding of long operated waterwall on the structure and hardness of the heat affected zone of welded joints

2017 ◽  
Vol 62 (1) ◽  
pp. 327-333 ◽  
Author(s):  
J. Pikuła ◽  
M. Łomozik ◽  
T. Pfeifer
Keyword(s):  
Heat Affected Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Power Plants ◽  
Welded Joint ◽  
Weld Bead ◽  
Boiler Steel ◽  
Metallographic Examination ◽  
Metal Arc Welding ◽  
High Degree

Abstract Welded installations failures of power plants, which are often result from a high degree of wear, requires suitable repairs. In the case of cracks formed in the weld bead of waterwall, weld bead is removed and new welded joint is prepared. However, it is associated with consecutive thermal cycles, which affect properties of heat affected zone of welded joint. This study presents the influence of multiple manual metal arc welding associated with repair activities of long operated waterwall of boiler steel on properties of repair welded joints. The work contains the results of macro and microscopic metallographic examination as well as the results of hardness measurements.

Gas metal arc welding of XPF800 steel for automotive industry: Microstructural evaluation and mechanical properties investigation

2021 ◽  
pp. 146442072110567
Author(s):  
Emre Korkmaz ◽  
Cemal Meran
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Automotive Industry ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Charpy Impact ◽  
Optical Microscope ◽  
Metal Arc Welding ◽  
Heat Affected Zone Softening

In this study, the effect of gas metal arc welding on the mechanical and microstructure properties of hot-rolled XPF800 steel newly produced by TATA Steel has been investigated. This steel finds its role in the automotive industry as chassis and seating applications. The microstructure transformation during gas metal arc welding has been analyzed using scanning electron microscope, optical microscope, and energy dispersive X-ray spectrometry. Tensile, Charpy impact, and microhardness tests have been implemented to determine the mechanical properties of welded samples. Acceptable welded joints have been obtained using heat input in the range of 0.28–0.46 kJ/mm. It has been found that the base metal hardness of the welded sample is 320 HV0.1. On account of the heat-affected zone softening, the intercritical heat-affected zone hardness values have diminished ∼20% compared to base metal.

Arc Fusion Welding of Mg-Al2Ca-Added Al 5xxx Alloys

2017 ◽  
Vol 371 ◽  
pp. 25-30
Author(s):  
Min Jung Kang ◽  
Cheol Hee Kim
Keyword(s):  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Al Alloys ◽  
Fusion Welding ◽  
Al Alloy ◽  
Alloy Specimen ◽  
Metallurgical Properties ◽  
Metal Arc Welding ◽  
Al 5052 Alloy

When casting ECO Al alloys, Mg-Al2Ca is used as a substitute for elemental Mg during the alloying process. Several previous studies have determined the mechanical and metallurgical properties of the ECO Al 5052 alloy. In this study, the weldability of the ECO Al 5052 alloy was determined. Gas metal arc welding was performed, and the resultant mechanical and metallurgical aspects of the welds in ECO Al 5052 alloy and commercial Al 5052 alloy were examined. In comparison to the commercial Al 5052 alloy specimen, the welds produced in the ECO Al 5052 alloy exhibited a very narrow heat-affected zone and were not softened through grain coarsening. Consequently, almost 100% joint efficiencies were observed in ECO Al alloy welds, in comparison to joint efficiencies of only 82% in conventional Al 5052 alloy welds.

scholarly journals Pulse spray gas metal arc welding of advanced high strength S650MC automotive steel

10.30544/682 ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 505-517
Author(s):  
Ashok Kumar Srivastava ◽  
Pradip K Patra
Keyword(s):  
Weld Joint ◽  
Heat Input ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
High Strength Steels ◽  
High Strength ◽  
Filler Wire ◽  
Advanced High Strength Steels ◽  
Metal Arc Welding ◽  
The Impact

With an increasing demand for safer and greener vehicles, mild steel and high strength steel are being replaced by much stronger advanced high strength steels of thinner gauges. However, the welding process of advanced high strength steels is not developed at the same pace. The performance of these welded automotive structural components depends largely on the external and internal quality of weldment. Gas metal arc welding (GMAW) is one of the most common methods used in the automotive industry to join car body parts of dissimilar high strength steels. It is also recognized for its versatility and speed. In this work, after a review of GMAW process and issues in welding of advanced high strength steels, a welding experiment is carried out with varying heat input by using spray and pulse-spray transfer GMAW method with filler wires of three different strength levels. The experiment results, including macro-microstructure, mechanical properties, and microhardness of weld samples, are investigated in detail. Very good weldability of S650MC is demonstrated through the weld joint efficiency > 90%; no crack in bending of weld joints, or fracture of tensile test sample within weld joint or heat affected zone (HAZ), or softening of the HAZ. Pulse spray is superior because of thinner HAZ width and finer microstructure on account of lower heat input. The impact of filler wire strength on weldability is insignificant. However, high strength filler wire (ER100SG) may be chosen as per standard welding practice of matching strength.

Hexavalent Chromium Exposure Levels Resulting from Shipyard Welding

1998 ◽  
Vol 14 (04) ◽  
pp. 246-254
Author(s):  
Bhaskar Kura ◽  
Praveen Mookoni
Keyword(s):  
Hexavalent Chromium ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Task Group ◽  
Health Administration ◽  
Metal Arc Welding ◽  
Flux Cored Arc Welding ◽  
Exposure Levels ◽  
The Impact ◽  
Welding Processes

The Occupational Safety and Health Administration is expected to reduce permissible exposure limits of hexavalent chromium from 100 ng/m3between 5 to 0.5 fig/m3. A Navy Industry Task Group study revealed that the impact of proposed regulations on the shipbuilding industry is significant. The estimated cost of compliance by the Navy facilities could be as much as $46 Million/year besides a one-time cost of about $22 Million. Also, the task group estimated that the cost of $9 Million. This paper presents the results of a study undertaken at the University of New Orleans in support of the Navy/Industry Task Group efforts. The study included assessments of Cr(VI) exposure levels for two specific welding processes and three welding scenarios. Airborne particulate matter was collected using personal samplers for two specific welding processes, Gas Metal Arc Welding and Flux-Cored Arc Welding. Two base metals, HY100 and DH36, were considered for Flux-Cored Arc Welding and one base metal, HY100, was considered for Gas Metal Arc Welding. The samples were analyzed for Cr(VI) using OSHA Method 215. Based on the data generated, it can be concluded that Gas Metal Arc Welding and Flux-Cored Arc Welding on HY100 steel result in 8-hr. worker exposures less than 0.5 fig/m3 in a laboratory type setting, though the same levels of exposure may be difficult to be achieved in the field. Flux-Cored Arc Welding on DH36 resulted in exposure above 0.5 ng/m3, again in laboratory type setting.

Cladding of Wear-Resistant Layers in Metallurgy and Engineering

2016 ◽  
Vol 862 ◽  
pp. 41-48
Author(s):  
Ján Viňáš ◽  
Miroslav Greš ◽  
Tomáš Vaško
Keyword(s):  
Arc Welding ◽  
Experimental Testing ◽  
Gas Metal Arc Welding ◽  
Metallographic Analysis ◽  
Cored Wire ◽  
Laboratory Conditions ◽  
Metal Arc Welding ◽  
The Impact ◽  
Welding Processes ◽  
Cladding Layers

The paper presents the application of weld layers used in renovations of functional surfaces of components that are exposed to several tribodegradation factors in operation of metallurgical and engineering industries. Surfaces of selected components are renovated using arc welding processes, namely: (MMAW) Manual Metal Arc Welding, (SAW) Submerged Arc Welding methods, (GMAW) Gas metal arc welding and (FCAW) Flux cored wire metal arc welding without gas shield. Claddings were made always three-layered directly on the surfaces of renovated components using dedicated cladding machines in operations and laboratory conditions respectively. Their quality was assessed using non-destructive tests, namely (VT) visual testing by STN EN ISO 17637 and (UT) Ultrasonic testing STN EN ISO 11666. Within the destructive tests the quality of claddings was evaluated using the metallographic analysis conducted on a light microscope Olympus BX and electron microscope Jeol where the impact of mixing the weld metal as well as heat treatment after cladding on the final structure of claddings was observed. Using the Shimadzu HMV 2 device the microhardness of cladding layers was evaluated on metallographic samples by STN EN ISO 9015-2. In laboratory conditions the resistance of cladding layers to abrasive wear was verified on the device Di-1. Experimental testing of the claddings confirmed that the selected additives and cladding parameters witting individual technology were chosen correctly as in cladding layers no presence of internal defects was observed.

Experimental Study on Tensile Strength of Butt Joints for Mild Steel with Thickness 6mm Using Gas Metal Arc Welding (GMAW)

2017 ◽  
Vol 740 ◽  
pp. 155-160 ◽  
Author(s):  
Z.A. Zakaria ◽  
K.N.M. Hasan ◽  
M.F.A. Razak ◽  
Amirrudin Yaacob ◽  
A.R. Othman
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Current ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Low Carbon ◽  
Metal Arc Welding

In this study, the effects of various welding parameters on welding strength in low carbon steel JIS G 3101 SS400, welded by gas metal arc welding were investigated. Welding current, arc voltage and travel speed are the variable parameters were studied in this study. The ultimate tensile strength, hardness and heat affected zone were measured for each specimen after the welding operations, and the effects of these parameters on strength were examined. Then, the relationship between welding parameter and ultimate tensile strength, hardness and heat affected zone were determined. Based on the finding, the best parameter is formulated and used to calculate the heat input.

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