The continuous casting test for high-speed steel W6Mo5Ci4V2 is carried out by using 150 kg medium frequency induction electric furnace- 150 kg interim ladle and designed Φ100 mm vertical continuous caster with mold vibration frequency 1. 2 Hz and vibration amplitude ± 3 mm

casting speed 0. 4 m/min and secondary cooling water pressure 0. 2 MPa

and the thickness of ledeburite net and solidification cooling rate of the high-speed steel at different process conditions are measured. Results show that as compared with 15 kg common ingot mold casting high-speed steel W6Mo5Cr4V2

the structure of high speed steel Φ100 mm casting billet by vertical continuous casting process is dense without defects

the ledeburite net is obviously thinner

the average thickness of

ledeburite net at center of casting billet is ≤16μm

and the grains markedly fine； the precipitated amount of carbide M

2

C and MC obviously increases while the carbide M

6

C precipitated amount decreases

and the carbides are more fine

homogeneous and dispersed; the solidification cooling rate at edge of casting billet is 3. 33 x 10

4

K/s

at r/2 is 9. 4 x 10

3

K/s and at center is 8. 1 x 10

2

K/s

its metallurgical quality is obviously higher than that of common ingot mold casting.