Smelting high purity 55SiCr automobile suspension spring steel with different refractories

We performed a laboratory investigation at 1,873 K using a MoSi furnace to study the effect of refractories on inclusions in 55SiCr suspension spring steel. Three types of crucible materials (Al , MgO·Al , and MgO–CaO) were investigated. The results of this study indicated that SiO , Al , and MgO·Al 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 Al inclusions.