Inclusion modification of E36 shipbuilding steel containing yttrium

In order to study the effect of yttrium on the composition and morphology of inclusions in E36 shipbuilding steel, the thermodynamic calculation of the main inclusions in E36 shipbuilding steel after adding rare earth yttrium was firstly carried out. And the inclusions in E36 shipbuilding steel before and after yttrium treatment were analyzed by scanning electron microscopy and energy spectrum. The results showed that the inclusions in E36 shipbuilding steel without rare earth yttrium were mainly chain-type MnS inclusions. After the addition of yttrium, the inclusions in E36 shipbuilding steel were mainly spherical or spheroidal composite inclusions containing yttrium. When the mass fraction of yttrium in the steel was 0.007 8%, the inclusions were mainly spherical or spheroidal Y₂O₂S and Y₂O₃ inclusions. When the mass fraction of yttrium in the steel reached 0.037 7%, the inclusions were mainly spherical or spheroidal Y₂O₂S, YS and Y₂O₃ inclusions.