Full
Outline
To tackle the issue of microstructural segregation in nickel-based alloy weldments and the consequent degradation of joint mechanical properties， this study delves into the impacts of two post-weld heat treatment schedules on the microstructural features and mechanical behavior of gas tungsten arc-welded Incoloy 825 nickel-based alloy joints.The results reveal that both heat treatment procedures lead to a notable coarsening of fine grain boundary carbides in the base metal （BM）. Moreover， the γ′ phase can be precipitated within BM grains through solution treatment combined with two-stage aging. Both post-weld heat treatments facilitate extensive precipitation of the δ and Laves phases in the WZ interdendritic zones， effectively alleviating segregation. Nevertheless， joints subjected to solution treatment and two-stage aging develop microcracks at the interface between the unmixed zone （UMZ） and the heat-affected zone （HAZ）， along with the formation of micropores within the HAZ. Mechanical characterization indicates a substantial increase in microhardness in the weld zone （WZ） after both heat treatment protocols. Solution treatment with single-stage aging maintains hardness levels in the HAZ and BM that are comparable to those in the as-welded state. Joints treated with solution treatment and single-stage aging show a marginal reduction in tensile strength， accompanied by a 9.2% improvement in uniform elongation， and fracture exclusively occurs within the BM. Conversely， the tensile strength of joints treated with solution treatment and two-stage aging significantly rises to 795 MPa， an increase of 17.3%， while the uniform elongation decreases. The fracture localization shifts to the UMZ/HAZ interfacial regions and adjacent HAZ areas， presenting a ductile-brittle mixed fracture morphology.
63
29
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
