Simulation Of Subrapid Solidification And Secondary Cooling For The Strip Casting Of If Steel

A combination of droplet solidification tester and confocal laser scanning microscope was used to simulate subrapid solidification and secondary cooling process pertinent to the strip casting. The IF steel droplet had a delamination structure and the bottom part went through sub-rapid solidification. During secondary cooling, gamma/alpha transformation mechanism belonged to interface-controlled massive transformation and the ferrite grains grew quickly. With the increase of cooling rate, the gamma/alpha transformation temperature decreased and the incubation period and phase transformation duration reduced. The hardness showed a slight increase due to fine-grain strengthening. With coiling temperature increasing from 600 degrees C to 800 degrees C, the grain size became larger, precipitates became coarse, and defects in grain were recovered. Consequently, the hardness decreased.