The invention provides an
inclusion control method of an Si-Mn-killed non-oriented
silicon steel, and belongs to the technical field of steel
smelting. The non-oriented
silicon steel comprises the following chemical components: not greater than 0.005% of C, 0.4-1.0% of Si, 0.20-0.80% of Mn, not greater than 0.04% of P, not greater than 0.005% of S, not greater than 0.005% of Als, and the balance Fe and inevitable impurities. The method comprises the processes of
smelting through a converter, refining under RH and vacuum, and continuously
casting; the
slag amount of the steel from the converteris strictly controlled;
lime, synthetic
slag and
calcium carbide are added to adjust the
slag; the refining under HR and vacuum is that a deep decarbonization mode is carried out; after decarbonization,
metallic aluminum is added to realize preliminary dexidation, and SiC is added to the
ladle slag surface at the same time in order to deoxidize and modify the slag; the operation is circulated for1-3min; then low-carbon low-
titanium ferrosilicon is added to realize Low carbon, low
titanium ferrosilicon; the operation is circulated for 3-6min, then
manganese metal, ferrophosphorus and the likeare added to
alloy, and the net circulating time is beyond 8min after alloying. With the adoption of the method, the composition of
nonmetal inclusions in the steel can be improved, so that the performances of the non-oriented
silicon steel can be improved, and the foundation is supplied to develop high-performance non-oriented silicon steels.