Molecular dynamics is applied to study the layer density profiles, layer structure factors and layer radial distribution function of the slab in order to research the premelting phenomena and meltin.

Using the modified analytic embedded-atom method(MAEAM),the molecular dynamics(MD) simulation was performed to study the premelting and melting behavior of (001) plane of niobium and tungsten.

Integrating carbon-free,premelting,hollowness and basicity,the TB-P tundish powder is of the CaO-MgO-Al2O3-SiO2 slag family and of a hollow spherical product with CaO/SiO2 > 2, MgO ( 14 ± 4 .

In the experimental research of hot metal pre-treatment dephosphorizer consisting of CaO-oxide scale-CaF2,it is proved that both pre-melted dephosphorizer and solid synthesis dephosphorizer can reduce the P-content to less than 0.

Contraposing to the defects of desulphurizer of CaO-CaF_2 system,a new pre-melted desulphurizer based on CaO-Al_2O_3-SiO_2 system was developed,in which some components with high basicity and good sulfur capacity were added.

The present paper studies the hot metal dephosphorization using the CaO-Fe_2O_3-CaF_2 slag series and its premelted slag as dephosphorizer.

The desulphurizing efficiency,its influencing factors and the influence on the content of steel by premelted slag on BOF tapping have been studied.

It is indicated that:(1) slag Infiltration Desulphurization takes place in the first few minutes when converter slag is put in ladle,the parameters of premelted slag such as melting point,melting speed,wettability and sulfur capability play an decisive role;(2) the content CaO of premelted sl.

Using molecular dynamics simulation,the pre-melting temperature of Fe_55 cluster was studied by the change of root mean squart bond length fluctuation,and the relationship between energy and configuration was discussed.

We found that these Pdn clusters all have pre-melting phenomenon.