DIAO Wangzhan, ZHANG Song, WANG Ping, et al.Mechanical Properties and Microstructure of Iron-nickel Based Alloy HT700P Welded Joint[J].Electric Welding Machine, 2024, 54(10): 53-60.
DIAO Wangzhan, ZHANG Song, WANG Ping, et al.Mechanical Properties and Microstructure of Iron-nickel Based Alloy HT700P Welded Joint[J].Electric Welding Machine, 2024, 54(10): 53-60. DOI: 10.7512/j.issn.1001-2303.2024.10.06.
The mechanical TIG was used to weld the large diameter pipe ring seam of iron-nickel based alloy HT700P. After the welding and stabilization heat treatment (980 ℃/3 h/AC) was qualified by non-destructive testing (100% PT+100% RT+100% PAUT)
the welded joint was subjected to tensile strength
bending
hardness performance
impact
high temperature endurance performance
and microstructure tests. The test results showed that the tensile strength and yield strength of the welded joint at room temperature were higher than the lower limit of the HT700P alloy
and the bending test was qualified. The hardness of the BM and HAZ in the welded joint is significantly higher than weld seam
while there is no significant difference in hardness between the base metal and heat affected zone. The average room temperature impact at the weld seam is 160.7 J
and at the HAZ is 102.3 J
both of which are higher than the lower limit of the HT700P alloy. The persistent strength of the welded joint for 10
5
hours is σ=138.3 MPa. The macro and micro metallographic structure of the welded joint is qualified
and the microstructure of the weld is austenite without the precipitation of harmful phases such as TCP.
关键词
HT700P铁镍基合金TIG力学性能微观组织650 ℃超超临界电站
Keywords
HT700P iron-nickel based alloyTIGmechanical propertymicrostructure650 ℃ ultra-supercritical power plant
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