Microstructural characteristics and tensile properties of gas tungsten constricted arc (GTCA) welded Inconel 718 superalloy sheets for aeroengine components

2020 ◽  
Vol 62 (11) ◽  
pp. 1099-1108
Author(s):  
Tushar Sonar ◽  
Visvalingam Balasubramanian ◽  
Sudersanan Malarvizhi ◽  
Annamalai Nagar ◽  
Thiruvenkatam Venkateswaran ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Grain Refinement ◽  
Fusion Zone ◽  
Welded Joints ◽  
Arc Welding ◽  
Inconel 718 ◽  
Microstructural Characteristics ◽  
Gtaw Process ◽  
Inconel 718 Superalloy ◽  
Gas Tungsten

Abstract Inconel 718 is a nickel-based superalloy, typically used in high temperature aerospace applications due to its exceptional mechanical properties and weldability. However, it is susceptible to solute segregation and coarser interconnected laves phase evolution in weld metal due to the high heat input in the gas tungsten arc welding (GTAW) process which drastically reduces the tensile properties of welded joints. It is also susceptible to HAZ microfissuring and liquation cracking issues owing to the evolution of low melting temperature eutectic film at the grain boundaries. To overcome this problem, a newly emerged novel gas tungsten constricted arc welding (GTCAW) process, principally differentiated by magnetic arc constriction and high frequency accentuation of the arc, is used to join Inconel 718 superalloy. The primary objective of this investigation is to evaluate the microstructural characteristics and tensile properties of GTCA welded Inconel 718 superalloy sheets (2 mm thick), fabricated using optimized process parameters, and compare its performance with the base metal. Results showed that GTCA welded joints exhibited 99.20 % and 73.5 % of base metal strength and ductility claiming significant advantages over the GTAW process. It is correlated to the grain refinement in the fusion zone and the evolution of finer discrete laves phase in interdendritic areas of the weld. The basic mechanism responsible for fusion zone grain refinement and corresponding influence on tensile properties of joints is also discussed in brief with regard to the mechanics of arc constriction and pulsing.

Microstructural characteristics and tensile properties of gas tungsten constricted arc (GTCA) welded Inconel 718 superalloy sheets for aeroengine components

2020 ◽  
Vol 62 (11) ◽  
pp. 1099-1108
Author(s):  
Tushar Sonar ◽  
Visvalingam Balasubramanian ◽  
Sudersanan Malarvizhi ◽  
Thiruvenkatam Venkateswaran ◽  
Dhenuvakonda Sivakumar
Keyword(s):  
Tensile Properties ◽  
Inconel 718 ◽  
Microstructural Characteristics ◽  
Inconel 718 Superalloy ◽  
Gas Tungsten ◽  
Aeroengine Components

scholarly journals Effect of Delta Current and Delta Current Frequency on tensile properties and microstructure of Gas Tungsten Constricted Arc (GTCA) welded Inconel 718 sheets

2019 ◽  
Vol 28 (1) ◽  
pp. 186-200 ◽  
Author(s):  
Tushar Sonar ◽  
Visvalingam Balasubramanian ◽  
Sudersanan Malarvizhi ◽  
Thiruvenkatam Venkateswaran ◽  
Dhenuvakonda Sivakumar
Keyword(s):  
Tensile Properties ◽  
Heat Input ◽  
Arc Welding ◽  
Inconel 718 ◽  
High Heat ◽  
Inconel 718 Alloy ◽  
Current Frequency ◽  
High Heat Input ◽  
Gtaw Process ◽  
Gas Tungsten

AbstractInconel 718 is a nickel-based superalloy which finds major applications in lightweight welded frames and other parts in gas turbine engines. This alloy is frequently joined by gas tungsten arc welding (GTAW) process for clean and precise welds. However, the weldability of Inconel 718 alloy is limited by the high heat input and slower cooling rate in GTAW process. It leads to the segregation of alloying elements and detrimental laves phase formation in weld metal which significantly reduces the tensile properties of the welded joints. To overcome this problem, a newly developed gas tungsten constricted arc welding (GTCAW) process is used for joining Inconel 718 alloy. The main effect of Delta Current (DC) and Delta Current Frequency (DCF) on the tensile properties and microstructure of GTCA welded 2 mm thick Inconel 718 alloy sheets was investigated. Superior tensile properties were exhibited at Delta Current of 50 A and Delta Current Frequency of 4 kHz due to the refinement in fusion zone. Delta Current and Delta Current Frequency showed deleterious effect at higher levels due to the high heat input.

scholarly journals Arc Characteristics and Weld Bead Microstructure of Ti-6Al-4V Titanium Alloy in Ultra-high Frequency Pulse Gas Tungsten Arc Welding (UHFP-GTAW) Process

2020 ◽  
Vol 26 (4) ◽  
pp. 426-431
Author(s):  
Wei LI ◽  
Gaochong LV ◽  
Qiang WANG ◽  
Songtao HUANG
Keyword(s):  
Titanium Alloy ◽  
Fusion Zone ◽  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Weld Bead ◽  
Gas Tungsten Arc ◽  
Arc Characteristics ◽  
Arc Pressure ◽  
Gtaw Process ◽  
Gas Tungsten

To resolve the problem of grain coarsening occurring in the fusion zone and the heat-affected zone during conventional gas tungsten arc welding(C-GTAW) welded titanium alloy, which severely restricts the improvement of weld mechanical properties, welding experiments on Ti-6Al-4V titanium alloy by adopting ultra-high frequency pulse gas tungsten arc welding (UHFP-GTAW) technique were carried out to study arc characteristics and weld bead microstructure. Combined with image processing technique, arc shapes during welding process were observed by high-speed camera. Meanwhile the average arc pressure under various welding parameters were obtained by adopting pressure measuring equipment with high-precision. In addition, the metallographic samples of the weld cross section were prepared for observing weld bead geometry and microstructure of the fusion zone. The experimental results show that, compared with C-GTAW, UHFP-GTAW process provides larger arc energy density and higher proportion of arc core region to the whole arc area. Moreover, UHFP-GTAW process has the obviously effect on grain refinement, which can decrease the grain size of the fusion zone. The results also revealed that a significant increase of arc pressure while increasing pulse frequency of UHFP-GTAW, which could improve the depth-to-width ratio of weld beads.

Mitigation of hot cracking in Inconel 718 superalloy by ultrasonic vibration during gas tungsten arc welding

2018 ◽  
Vol 740 ◽  
pp. 870-878 ◽  
Author(s):  
R. Thavamani ◽  
V. Balusamy ◽  
Jayakrishnan Nampoothiri ◽  
R. Subramanian ◽  
K.R. Ravi
Keyword(s):  
Ultrasonic Vibration ◽  
Arc Welding ◽  
Inconel 718 ◽  
Gas Tungsten Arc Welding ◽  
Hot Cracking ◽  
Gas Tungsten Arc ◽  
Inconel 718 Superalloy ◽  
Gas Tungsten

scholarly journals Structure of MMCs with SiC Particles after Gas-tungsten Arc Welding

2015 ◽  
Vol 15 (4) ◽  
pp. 65-68 ◽  
Author(s):  
E. Przełożyńska ◽  
K.N. Braszczyńska-Malika ◽  
M. Mróz
Keyword(s):  
Fusion Zone ◽  
Arc Welding ◽  
Welding Process ◽  
Welding Current ◽  
Gta Welding ◽  
Magnesium Matrix ◽  
Gas Tungsten Arc ◽  
Sic Particles ◽  
Gtaw Process ◽  
Gas Tungsten

Abstract The gas-tungsten arc (GTA) welding behaviors of a magnesium matrix composite reinforced with SiC particles were examined in terms of microstructure characteristics and process efficiencies. This study focused on the effects of the GTAW process parameters (like welding current in the range of 100/200 A) on the size of the fusion zone (FZ). The analyses revealed the strong influence of the GTA welding process on the width and depth of the fusion zone and also on the refinement of the microstructure in the fusion zone. Additionally, the results of dendrite arm size (DAS) measurements were presented.

INVESTIGATION OF PULSE FREQUENCY ON FUSION ZONE CHARACTERISTICS OF GTA WELDED AZ31B MAGNESIUM ALLOY JOINTS

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Subravel V
Keyword(s):  
Magnesium Alloy ◽  
Tensile Properties ◽  
Fusion Zone ◽  
Welding Speed ◽  
Pulse Frequency ◽  
Pulsed Current ◽  
Az31b Magnesium Alloy ◽  
Gas Tungsten Arc ◽  
Gas Tungsten ◽  
Different Levels

In this investigation an attempt has been made to study the effect of welding on fusion characteristics of pulsed current gas tungsten arc welded AZ31B magnesium alloy joints. Five joints were fabricated using different levels of welding speed (105 mm/min –145 mm/min). From this investigation, it is found that the joints fabricated using a welding speed of 135 mm/min yielded superior tensile properties compared to other joints. The formation of finer grains and higher hardness in fusion zone and uniformly distributed precipitates are the main reasons for the higher tensile properties of these joints

scholarly journals Improvement in the Microstructure and Tensile Properties of Inconel 718 Superalloy by HIP Treatment

2006 ◽  
Vol 47 (11) ◽  
pp. 2877-2881 ◽  
Author(s):  
Shih-Chin Lee ◽  
Shih-Hsien Chang ◽  
Tzu-Piao Tang ◽  
Hsin-Hung Ho ◽  
Jhewn-Kuang Chen
Keyword(s):  
Tensile Properties ◽  
Inconel 718 ◽  
Inconel 718 Superalloy

In-Situ Neutron Diffraction Study of Gas Tungsten Arc Welding of a 1018 Plain Carbon Steel

2007 ◽  
Vol 1027 ◽  
Author(s):  
Michael Gharghouri ◽  
Michael J Watson ◽  
David Dye ◽  
Ronald B Rogge
Keyword(s):  
Neutron Diffraction ◽  
Arc Welding ◽  
Neutron Diffraction Study ◽  
Plain Carbon Steel ◽  
Gas Tungsten Arc Welding ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Gas Tungsten ◽  
In Situ Neutron Diffraction

AbstractIn-situ neutron diffraction measurements of a dynamic Gas Tungsten Arc Welding (GTAW) process have been performed using a unique instrument that establishes steady-state conditions by translating and rotating a cylindrical specimen past a stationary weld torch. The fixed neutron sampling volume is at a constant location with respect to the torch as new material is brought into the fusion zone. We present maps of lattice spacing and integrated intensity as a function of location about the weld torch, which provide insight into the temperature and phase distributions around the weld.

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