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Numerical and experimental investigation on friction stir welding of Ti- and Nb-modified 12 % Cr ferritic stainless steel
- Source :
- Journal of Manufacturing Processes. 59:223-237
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- A friction stir butt-welded Ti- and Nb-modified 12 % Cr ferritic stainless steel joint without any defects was successfully produced under low welding heat input. The welding heat cycles, temperature profiles, and degree of plastic deformation during welding were quantitatively evaluated based on the results of a rigid-viscoplastic thermo-mechanically coupled model. Microstructure development in the stir zone (SZ) and thermo-mechanically affected zone (TMAZ) was studied and comparatively analyzed. A fine duplex microstructure containing nearly 62.9 % martensite and 37.1 % ferrite was obtained in the SZ. Undissolved nanometer-sized precipitates during welding played a crucial role in grain refinement in the weld. Retardation of dynamic recrystallization (DRX) occurred in the SZ, and the recrystallized grains were no more than 8% of the materials. The dynamic recovery and continuous DRX experienced by the ferrite grains in the TMAZ of the advancing side were more intense than those on the retreating side, leading to a higher amount of high-angle boundaries and a 20.8 % reduction in dislocation density. The hardness and strength in the SZ apparently increased owing to refined grains and phase transformation. Both the heat-affected zone with a fully ferritic structure and the SZ exhibited superior low-temperature toughness.
- Subjects :
- 0209 industrial biotechnology
Toughness
Materials science
Strategy and Management
Metallurgy
02 engineering and technology
Welding
Management Science and Operations Research
021001 nanoscience & nanotechnology
Microstructure
Industrial and Manufacturing Engineering
law.invention
020901 industrial engineering & automation
law
Ferrite (iron)
Martensite
Dynamic recrystallization
Friction stir welding
0210 nano-technology
Subjects
Details
- ISSN :
- 15266125
- Volume :
- 59
- Database :
- OpenAIRE
- Journal :
- Journal of Manufacturing Processes
- Accession number :
- edsair.doi...........83ee12a5ba2a5ca2e53948a4e3028b1e