The vibrating-exciting nucleation device consists of exciting nucleation rod

up-down

vibrating

rod cooling

damping and temperature measuring system. During 45 t Q345B steel slab ingot casting

the vibrating-exciting nucleation bar with height 200 mm is located at center of casting ingot mould submerged in liquid 50 ~ 80 mm. Casting test results show that (1) the vibrating-exciting nucleation device is safe and reliable as using it during ingot casting； (2) with cooling gas rate up to 40 m

3

/h the incrustation phenomenon occurs on surface of vibrating rod body

while with 20 m

3

/h the rod surface is very smooth

so the appropriate gas flow rate is 20 〜40 m

3

/h and the temperature difference between surface of exciting nucleation rod and liquid is 55 〜80 ℃； (3) by nondestructive examination

the plate rolled by ingot with using vibrating-ex

citing nucleation processing is qualified with H rating while the contrast plate rolled by general ingot without using vibrating-exciting nucleation processing is unqualified due to existing continuous defects.