Abstract:
We performed a laboratory investigation at 1,873 K using a MoSi2 furnace to study the effect of refractories on inclusions in 55SiCr suspension spring steel. Three types of crucible materials (Al2O3, MgO center dot Al2O3, and MgO-CaO) were investigated. The results of this study indicated that SiO2, Al2O3, and MgO center dot Al2O3 were not suitable for making 55SiCr suspension spring steel. By contrast, MgO-CaO was a perfect choice for producing 55SiCr suspension spring steel. The advantages of using MgO-CaO crucibles to smelt 55SiCr spring steel were summarized in three aspects as follows: (i) the stability of MgO-CaO was quite good; (ii) a MgO-CaO crucible could act as a desulfurizer and dephosphorizer; (iii) finally, a MgO-CaO crucible could simultaneously remove Al2O3 inclusions.
