Table 3: Ferrite and bainite volume fractions of the heat-treated samples analyzed by metallography and image analysis.
Sample name | Starting microstructure | Austenitizing temperature (℃) | Austenitizing time (min) | Ferrite and bainite volume fractions |
HTS.1 | Pearlite ferrite | 855 | 30 | 62% Ferrite |
35% Bainite | ||||
HTS.2 | Martensite | 855 | 30 | 55% Ferrite |
45% Bainite | ||||
HTS.3 | Pearlite ferrite | 900 | 180 | 37% Ferrite |
63% Bainite | ||||
HTS.4 | Martensite | 900 | 180 | 53% Ferrite |
46% Bainite | ||||
HTS.5 | Pearlite ferrite | 900 | 120 | 45% Ferrite |
55% Bainite | ||||
HTS.6 | Martensite | 900 | 120 | 05% Ferrite |
95% Bainite | ||||
HTS.7 | Pearlite ferrite | 950 | 60 | 40% Ferrite |
60% Bainite | ||||
HTS.8 | Pearlite ferrite | 900 | 120 | 23% Ferrite |
77% Bainite | ||||
HTS.9 | Martensite | 900 | 120 | 29% Ferrite |
71% Bainite | ||||
HTS.10 | Pearlite ferrite | 900 | 120 | 40% Ferrite |
40% Ferrite | ||||
HTS.11 | Martensite | 900 | 120 | 04% Ferrite |
95% Bainite | ||||
HTS.12 | Pearlite ferrite | 900 | 120 | 06% Ferrite |
94% Bainite | ||||
HTS.13 | Martensite | 900 | 120 | 03% Ferrite |
97% Bainite | ||||
HTS.14 | Pearlite ferrite | 900 | 120 | 05% Ferrite |
95% Bainite |