Effect of the structure of ferrosilicon on its desintegration

The structure of commercial high-percentage ferrosilicon is analyzed. Chemical, X-ray diffraction, and electron-probe analyses are used to compare the self-desintegrated and intact ferrosilicon FS65 alloys manufactured at JSC Serov Ferroalloy Plant. The experimental results demonstrate a significant microheterogeneity caused by silicon segregation, which induces cracking in the alloy structure, and by the existence of magnesium, aluminum, titanium, and silicon phosphides, which can form phosphines during interaction with air moisture. To decrease the spontaneous desintegration of ferrosilicon, it is necessary to suppress segregation before casting, to optimize the silicon content range, and to decrease the concentrations of impurities (mainly phosphorus and aluminum, which are introduced into an alloy with charge materials).