By observing the morphological changes of primary austenite grains in as-cast hypoeutectic high Cr cast iron during isothermal remelting process in liquid-solid phase region

mechanism of its evolution was described. The results reveal that during isothermal remelting process

primary austenite phase is evolved from coarseness of net dendrite to fusion to spheroidization of grain and then to consolidation. Dendrite coarsening and fusing are dominant in evolution process at a lower remelting temperature

resulting in the difficulty of net austenite dendrite to be completely eliminated

while grain spheroidization and consolidation are dominant in evolution process at a higher remelting temperature. The equiaxed and uniform pre-eutectic austenite phase can be obtained in the high Cr cast iron at 1330℃ for 35 min. However

with increasing in heating temperature and in holding time

austenite phase can be seriously coarsened.