The large-sized flat titanium ingots（8 000mm×1 050mm×210mm）were prepared by electron beam cold hearth furnace.Effects of temperature-differential of melt surface in crystallizer on Fe segregation and its controlling method were investigated.The results show that

the phenomenon of the heterogeneous temperature and local overheating of the melt surface appears due to unreasonable distribution ratio of electron gun scanning power.Furthermore

with the increase of the average temperaturedifferential of the melt surface

the Fe content in flat ingots is decreased

and the degree of Fe segregation in the transverse direction becomes more serious.As a result

the smallest degree of Fe segregation in flat titanium ingots and the most balanced mechanical properties of titanium coils rolled by ingots can be observed with the crystallizer surface scanned by the electron gun with power distribution ratio of32%

28% and 40%to make the average temperature-differential of the melt surface minimum.