G.W. Chang
,
H.X. Wang
,
X.D.Yue
,
H.L. Zhang
金属学报(英文版)
For settling the question of feeding speed in applying the cored-wire method to spheroidize ductile iron melt, ANSYS software was applied to simulate the heat transfer and mass transfer, and the melt time of the steel strip in the iron melt was determined by linking the heat transfer and mass transfer, and then the feeding speed was calculated. Conclusions have been drawn that the iron layer was formed on the surface of the cored-wire during the wire-feeding process. The thickness is 0.073 mm when the temperature of the iron melt is 1500℃, the time from formation to remelting of the iron layer is 0.063~s. When the temperature of the iron melt is below 1500$^{\circ}$C, the time taken for the steel strip to melt is rapidly shortened. When the temperature of the iron melt is above 1500℃, the variation amplitude of the steel strip melt change with time is gradually diminished. The melt time of the steel strip is rapidly increased with the increase of the steel strip thickness. When the temperature of the iron melt is 1500℃ and the carbon content is 4 %, the melt time of a steel strip, which has a thickness of 0.5 mm, isthrice that of a steel strip whose thickness is 0.3 mm. The calculation results of the feeding speed are basically in agreement with the applied feeding speed in the factory.
关键词:
Ductile iron
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G.W. Chang
,
G.C. Jin
,
S.Y.Chen
,
X.D. Yue
金属学报(英文版)
According to the nature of the periodic bending deformation of solid-liquid interface in the solidification process of continuous casting slab，The nucleation and extension of crack was analyzed by the variation of temperature gradient and dendritic spacing in the front edge of solid-liquid interface. The results indicate that the bending deformation of interface makes temperature field change in the front edge of solid-liquid interface; the occurrence of temperature gradient along drawing direction provides the condition for the growth of secondary dendrites; The crack source formed during the middle and final stage of solidification may extend to the surface of casting slab and become internal crack. The theoretical analysis is basically agreement with the experimental results.
关键词:
continuous casting
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