The production flow sheet for heavy bloom of steel Q345E (/% : 0.14-0.17C

0.20-0.30Si

1.28-1.38Mn

≤0.011P

≤0.005S

0.015-0.030A1

0.032-0.045V) is 65 t LD-LF-VD-Φ600 mm round bloom CC process. With the measures including using sliding plate to stop slag in tapping

and adding pre-melted synthetic slag (/% : 40-50CaO

≤9SiO

2

30-40Al

2

O

3

3-7MgO

8-10A1)

steel-clad aluminium

deoxidizer and alloys

controlling casting speed 0.22 m/min

overheating extent of liquid (25 ± 5)℃ and constant liquid level 900 mm in 32 t tundish

whole process shield casting and electromagnetic stirring

the Φ600 mm casting round bloom of steel Q345E for flange is pilot-produced. The production results show that there is no visible surface defect such as scab and bulging

the rating of center li

ne shrinkage is 0.5

the center porosity 1.0 and the carbon segregation ≤1.09

and the impact energy of steel at -50 ℃ is more than 100 J

all meet the requirement.