The 1 mm deep cracks occured at surface of 80~95 mm square bars of 12Mn2VB non-quenching-tempering steel containing 0. 10%~0. 15% C produced by EBT EAF-LF steelmaking-650kg ingot casting with compound casting powder:16~20C
≥10Al₂O₃
35~40SiO₂
10~16CaO at Special Steel Co Lad
Benxi Iron and Steel
and the C cont- ent of surface at parts of an area was up to 0.62%.After using improved process -EBT EAF-LF steelmaking-3. 16t ingot casting with lower C content compound casting powder:≤12C
≥10Al₂O₃
35~40SiO₂
10~16CaO
the surface recarburization of rolled products obviously deceased which was available to control surface crack formation
therefore the yield of finished products increased to 82% from 74%.