Effect of Silicon Segregation in the Argon Arc Welded Incoloy 20 Superalloy.

Autor: Natesh, M., Selvaraj, Senthil Kumaran, Arivazhagan, N., Manikandan, M., Tofil, Szymon, Radek, Norbert, Mistry, Yash, SM, Muthu
Zdroj: SILICON (1876990X); Jan2023, Vol. 15 Issue 1, p365-379, 15p
Abstrakt: Incoloy 20 is prone to hot cracking due to micro-segregation of alloying elements. The aim of the work is to investigate the chances of curtailing the micro-segregation of elements using argon arc welding with Ni and Mo-rich filler wire. In this study, Incoloy 20 weldments are fabricated by continuous current argon arc welding (CCAAW) and pulsed current argon arc welding (PCAAW) with ERNiCrMo-14 filler wire. Crack-free welds with appropriate fluid flow are achieved through CCAAW and PCAAW. Advanced high-magnification microscopes exhibit the two different structures (cellular and columnar) in CCAAW and equiaxed structures in PCAAW. Energy Dispersive X-ray Spectroscopy (EDS) displays the Mo, W and Si segregation in CCAAW. Elemental segregation is majorly suppressed with PCAAW. X-Ray Diffraction analysis spotted the interstitial phases like Mo-rich M23C6, Si12C, and MoC at the weldments. Toughness and hardness of the weldments are noticed with slight enhancements in PCAAW (128 J) than that of CCAAW (121 J) due to the formation of interstitial phases. Higher tensile strength is observed in the PCAAW (635 MPa) than that of CCAAW (623 MPa) due to the low heat input during pulsed current welding. Electron Backscattered Diffraction (EBSD) analysis is used to observe the HAZ where failure occurs. Coarse grain structures are noticed in the HAZ of CCAAW. EBSD showed 26% lesser grain sizes for PCAAW than the CCAAW. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index