Microstructure and Precipitation Studies of Gas Tungsten Arc Welded Haynes 282 Superalloy

2021 ◽  
Vol 1016 ◽  
pp. 666-671
Author(s):  
Karna Sivaji ◽  
Gandham Phanikumar
Keyword(s):  
Arc Welding ◽  
Power Plants ◽  
Thermal Power ◽  
Gas Tungsten Arc ◽  
Nickel Based Superalloy ◽  
High Temperature Materials ◽  
Experimental Parameters ◽  
Service Conditions ◽  
Gas Tungsten ◽  
Carbide Precipitate

Improvement in efficiency of energy conversion requires the use of high temperature materials in thermal power plants. This has led to the development of new γ' strengthened nickel based superalloy (Haynes 282). This alloy is used for advanced ultra-supercritical (AUSC) plants which are operated under the service conditions of 760 oC temperature and 35 MPa pressure. Bead on plate gas tungsten arc welding experiments were done with optimized process parameters. Thermal cycle in heat affected zone was measured by K-type thermocouple attached to a data acquisition system. Welding simulations were carried out in simufact welding® by using experimental parameters and thermal field was established. Base metal is characterized with γ solid solution and randomly distributed MC carbides. SEM results showed that the carbides are of MC type. The carbide precipitate distribution correlates with the segregation pattern during solidification of the weld.

Effect of Inconel 625 on Microstructure and Mechanical Properties of Gas Tungsten Arc Welded Inconel-713LC Superalloy Joints

2019 ◽  
Vol 1156 ◽  
pp. 10-16
Author(s):  
Yu Chih Tzeng ◽  
Chih Ting Wu
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Inconel 625 ◽  
Strengthening Phase ◽  
X Ray ◽  
Gas Tungsten Arc ◽  
Nickel Based Superalloy ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
Gas Tungsten

This study investigates how the use of Inconel filler metal 625 affects the microstructure and mechanical properties of gas tungsten arc welded joints of an IN-713LC nickel-based superalloy. Due to their difference in composition, obvious weld beads could be found by X-ray detection. In addition, it was found that the γ' strengthening phase was absent and carbide was present between the matrix and the weld bead during gas tungsten arc welding. These carbides are strongly related to the formation of cracking and weld shrinkage during solidification. The absence of the γ' strengthening phase and the presence of weld shrinkage and cracking led to a decrease in the hardness, tensile strength, and elongation of the welded pieces.

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.

Modelling and measurements of gas tungsten arc welding in argon–helium mixtures with metal vapour

2021 ◽  
Author(s):  
Junting Xiang ◽  
Keigo Tanaka ◽  
Fiona F. Chen ◽  
Masaya Shigeta ◽  
Manabu Tanaka ◽  
...  
Keyword(s):  
Arc Welding ◽  
Gas Tungsten Arc Welding ◽  
Metal Vapour ◽  
Helium Mixtures ◽  
Gas Tungsten Arc ◽  
Gas Tungsten
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