Figure 3. Microstructures for different pouring temperatures and holding times with (a) pouring
temperature 660 °C and holding time 20 s, (b) pouring temperature 660 °C and holding time 60 s,
(c) pouring temperature 680 °C and holding time 20 s, (d) pouring temperature 680 °C and holding
time 60 s, (e) pouring temperature 700 °C and holding time 20 s, and (f) pouring temperature
700 °C and holding time 60 s.