Abstract
When a sulphur refining pot is made of ferro-alloys, it is attacked severely and so the studies were made on the sulphur corrosion of ferro-alloys.
Specimens were made of pure iron, Fe-C alloy and Fe-C-3rd. Elements alloyed specimens, and these were heated with pure sulphur in silica tube. The heating time and temperatures were varied, and the 3rd element is being Cr, Mn, Al or V.
Attacked specimens were cut down and the cut surface was examined by a microscope. The results obtained are as follows :
1. Ferrite was corroded easily but cementite gave a great resistance to corrosive tendency.
2. Specimens added 3rd element showed a great resistance to corrosion but specimens added Mn were relatively liable to corrode.
3. Corroded layers were devided into two layers. Grains in the outer layer were coarsened and arranged vertically to the surface of specimens while grains in the inner layer were put at random and the grain size was finer than that in the outer layer.
4. Cr or Al content differed widely in the outer and inner layers (though fewer in the outer layer) when Cr or Al as the 3rd element was added.
