scholarly journals Improving GMAW weld metal and HAZ properties through friction stir processing

2020 ◽  
Vol 65 (3) ◽  
pp. 137-142
Author(s):  
Gupta Kumar ◽  
Raja Ravi ◽  
Adarsh Kumar ◽  
Meghanshu Vashista ◽  
Khan Zaheer
Keyword(s):  
Weld Metal ◽  
Friction Stir Processing ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Milling Process ◽  
Friction Stir ◽  
Metal Arc Welding ◽  
Tungsten Carbide Tool ◽  
Standard Techniques

Steel is one of the most widely used engineering materials and it is popularly welded in fabrication industries using Gas metal arc welding (GMAW) process. The microstructure obtained in the heat affected zone is often characterized with large grain size. Depending on the GMAW process parameters, the weld metal may consist of Allotrimorphic ferrite if the heat input is high. Therefore, the weld metal and the heat affected zone may have poor weld metal toughness. Efforts have been made to modify the microstructure of the weld metal by performing friction stir processing. Initially bead on plate welding was performed on mild steel plate using GMAW process using standard 1.2 mm consumable wire and CO2 as the shielding gas. The top surface of the weld was processed using a tungsten carbide tool. The weld reinforcement was removed using milling process and the area to be processed was made smooth before performing FSP. The plate was secured in an FSW machine and friction stir processing was carried out with a FSW tool having pin length of 2 mm. The GMAW weld and the weld that has been subsequently modified using FSP were characterized using standard techniques. The microstructure of the top face showed an improvement from Widmanstätten to fine equiaxed structure after being friction stir processed. The microstructure in the HAZ also got refined. It is expected that this structure would improve the mechanical properties of the weld particularly on the surface.

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.

A study on sustainability assessment of welding processes

2019 ◽  
Vol 234 (3) ◽  
pp. 501-512 ◽  
Author(s):  
Jaber Jamal ◽  
Basil Darras ◽  
Hossam Kishawy
Keyword(s):  
Arc Welding ◽  
Social Impact ◽  
Sustainability Assessment ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Friction Stir ◽  
Gas Tungsten Arc ◽  
Metal Arc Welding ◽  
Sustainability Assessments ◽  
Welding Processes

The concept of “sustainability” has recently risen to take the old concept of going “green” further. This article presents general methodologies for sustainability assessments. These were then adapted to measure and assess the sustainability of welding processes through building a complete framework, to determine the best welding process for a particular application. To apply this methodology, data about the welding processes would be collected and segregated into four categories: environmental impact, economic impact, social impact, and physical performance. The performance of each category would then be aggregated into a single sustainability score. To demonstrate the capability of this methodology, case studies of three different welding processes were performed. Friction stir welding obtained the highest overall sustainability score compared to gas tungsten arc welding and gas metal arc welding.

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.

Fracture Mechanics of Conventional and Narrow Groove Pulse Current Gas Metal Arc Welds of HSLA Steel

2012 ◽  
Vol 710 ◽  
pp. 451-456
Author(s):  
Ravi Ranjan Kumar ◽  
P. K. Ghosh
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Tensile Properties ◽  
Arc Welding ◽  
Hsla Steel ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Compact Tension ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Mechanical and fracture properties of 20MnMoNi55 grade high strength low alloy (HSLA) steel welds have been studied. The weld joints were made using Gas Tungsten Arc Welding (GTAW), Shielded Metal Arc Welding (SMAW) and Pulse Gas Metal Arc Welding (P-GMAW) methods on conventional V-groove (V-Groove) and Narrow groove (NG-13). The base metal and weld metal were characterised in terms of their metallurgical, mechanical and fracture toughness properties by following ASTM procedures. The J-Integral fracture test was carried out using compact tension C(T) specimen for base and weld metal. The fracture toughness and tensile properties of welds have been correlated with microstructure. In conventional V-groove welds prepared by P-GMAW shows the improvement in initiation fracture toughness (JIC) as compared to the weld prepared by SMAW. Similar improvements in tensile properties have also been observed. This is attributed to reduction in co-axial dendrite content due to lower heat input during P-GMAW process as compared to SMAW. In the narrow groove P-GMA weld prepared at f value of 0.15 has shown relative improvement of JIC as compared to that of the weld prepared by SMAW process.

scholarly journals The State of the Art of Underwater Wet Welding Practice: Part 1

2021 ◽  
Vol 100 (4) ◽  
pp. 132-141
Author(s):  
EZEQUIEL CAIRES PEREIRA PESSOA ◽  
◽  
STEPHEN LIU
Keyword(s):  
Research And Development ◽  
Weld Metal ◽  
Arc Welding ◽  
Structural Steels ◽  
Friction Stir ◽  
Underwater Wet Welding ◽  
Class A ◽  
Metal Arc Welding ◽  
Flux Cored Arc Welding ◽  
Welding Processes

Developments in underwater wet welding (UWW) over the past four decades are reviewed, with an emphasis on the research that has been conducted in the last ten years. Shielded metal arc welding with rutile-based coated electrodes was established as the most applied process in the practice of wet welding of structural steels in shallow water. The advancements achieved in previous decades had already led to control of the chemical com-position and microstructure of weld metals. Research and development in consumables formulation have led to control of the amount of hydrogen content and the level of weld porosity in the weld metal. The main focus of research and development in the last decade was on weldability of naval and offshore structural steels and acceptance of welding procedures for Class A weld classification according to American Welding Society D3.6, Under-water Welding Code. Applications of strictly controlled welding techniques, including new postweld heat treatment procedures, allowed for the welding of steels with carbon equivalent values greater than 0.40. Classification societies are meticulously scrutinizing wet welding procedures and wet weld properties in structural steels at depths smaller than 30 m prior to qualifying them as Class A capable. Alternate wet welding processes that have been tested in previous decades — such as friction stir welding, dry local habitat, and gas metal arc welding —have not achieved great success as originally claimed. Al-most all of the new UWW process developments in the last decade have focused on the flux cored arc welding (FCAW) process. Part 1 of this paper covers developments in microstructural optimization and weld metal porosity control for UWW. Part 2 discusses the hydrogen pickup mechanism, weld cooling rate control, design, and qualification of consumables. It ends with a description of the advancements in FCAW applications for UWW.

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