Development of welding technique to avoid the sensitization in the alloy 600 by conventional Gas Tungsten Arc Welding method

2017 ◽  
Vol 30 ◽  
pp. 452-466 ◽  
Author(s):  
A. Srikanth ◽  
M. Manikandan
2016 ◽  
Vol 21 ◽  
pp. 201-213 ◽  
Author(s):  
K. Devendranath Ramkumar ◽  
Shah Vitesh Naren ◽  
Venkata Rama Karthik Paga ◽  
Ambuj Tiwari ◽  
N. Arivazhagan

Author(s):  
M Sathishkumar ◽  
M Manikandan

Alloy X is prone to liquation and solidification cracks in the weldments, because of the development of topologically close-packed precipitates such as σ, P, M6C, and M23C6 carbides during arc welding methods. The present work examines the possibility of alleviating the segregation of Cr and Mo content to eliminate the development of topologically close-packed phases using a conventional arc welding technique. The welding of Alloy X has been achieved with ERNiCrMo-2 filler material by gas tungsten arc welding and pulsed current gas tungsten arc welding technique. The optical microscope shows the refined microstructure in pulsed current gas tungsten arc with respect to gas tungsten arc welding. The Mo-rich segregation was identified in gas tungsten arc weldment, and the same was absent in pulsed current gas tungsten arc. These segregations of Mo-rich content encourage the development of M3C and M6C secondary precipitates in gas tungsten arc welding. Pulsed current gas tungsten arc welding shows the existence of NiCrCoMo precipitate. The present work confirmed the absence of P, σ, and M23C6 in both the weldments of Alloy X. The ultimate tensile strength, microhardness, and impact strength of pulsed current gas tungsten arc welding are increased by 3.39, 9.17, and 21.62%, respectively, with gas tungsten arc welding. The observed Mo-rich M3C and M6C secondary phases in the gas tungsten arc welding affect the tensile strength of the weldments.


1996 ◽  
Vol 14 (4) ◽  
pp. 633-640 ◽  
Author(s):  
Yoshikazu Suita ◽  
Yoshiyuki Tsukuda ◽  
Noboru Terajima ◽  
Hisashi Takahashi ◽  
Masanobu Ogasawara ◽  
...  

2020 ◽  
Vol 26 (4) ◽  
pp. 426-431
Author(s):  
Wei LI ◽  
Gaochong LV ◽  
Qiang WANG ◽  
Songtao HUANG

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.


Sign in / Sign up

Export Citation Format

Share Document