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Figure 1
Optical micrographs specimen in solution annealed state: (a) rolling direction and (b) transverse direction, Murakami's reagent (etching at high temperature), 200×.
Figure 2
Optical micrographs specimen heat treated at 750°C for (a) 5, (b) 15, (c) 30, (d) 60, (e) 120 and (f) 180 min, Murakami's reagent (etching at high temperature), 500×.
Figure 3
Optical micrographs specimen heat treated at 850°C for (a) 5, (b) 15, (c) 30, (d) 60, (e) 120 and (f) 180 min, Murakami's reagent (etching at high temperature), 500×
Figure 4
Micrograph of transformation of the δ-ferrite using scanning electron microscope after annealing at 750°C for 5 min, 3,000×.
Figure 5
Micrograph of σ-phase using scanning electron microscope after annealing at 750°C for 30 min, 3,000×.
Figure 6
Optical micrographs specimen heat treated: (a) at 750°C for 30 min (cooling in air) and (b) at 850°C for 30 min (cooling in air), Murakami's reagent (etching at room temperature), 500×.
Figure 7
The δ-ferrite content in annealed samples.
Figure 8
Hardness testing for different temperatures and time.
Energy-dispersive spectrometer analysis
Chemical composition, wt.%
Si
Cr
Fe
Ni
Spectrum 1
5.01
33.27
55.65
4.1
Spectrum 2
4.57
26.28
60.73
6.11
Spectrum 3
3.52
20.01
67.04
7.80
Spectrum 4
3.57
20.35
67.92
8.16
Chemical composition of tested austenitic stainless steel