The effect of solution annealing on the microstructural behavior of alloy 22 welds

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2006-03, Vol.37 (3A), p.1027-1038
• Main Authors: EL-DASHER, Bassem S, EDGECUMBE, Tammy S, TORRES, Sharon G
• Format: Article
• Language: English
• Subjects: Alloys; Applied sciences; Exact sciences and technology; Joining, thermal cutting: metallurgical aspects; Materials science; Metallurgy; Metals. Metallurgy; Microstructure; Welding
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-006-0075-1

Multipass gas tungsten arc welds of alloy 22 were subjected to solution annealing durations of 20 minutes, 24 hours, 72 hours, and 1 week at temperatures of 1075 °C, 1121 °C, 1200 °C, and 1300 °C. The specimens were studied in cross section by secondary electron microscopy to determine the effect of solution annealing on tetraheclrally close-packed (TCP) precipitate stability. Electron backscatter diffraction mapping was also performed on all of the specimens to determine the recrystallization behavior of the welds. It was found that complete TCP precipitate dissolution occurs after solution annealing at 1075 °C and 1121 °C for 24 hours, and at 1200 °C and 1300 °C for durations of 20 minutes. Regions of most rapid recrystallization were correlated to the regions of lowest solute content, highest plastic strain, and highest residual stresses. Texture analysis indicated that while the columnar dendrites originally present in the weld grew with a orientation in the transverse direction (approximately opposite the heat flow direction), the recrystallized grains adopt a orientation in the transverse direction when recrystallization and TCP phase dissolution occur simultaneously. [PUBLICATION ABSTRACT]