Ferro Alloys Ferro Alloys High Carbon Ferro Chrome Cr: 62.0-72.0% C: 6.0-8.0% Si: 3.0% max. (<80%) S: 0.05% max. P: 0.03% max. Ferro Silicon Si: 74.0-79.0% S: 0.025% max. Mn: 0.40% max. Al: 1.50% max. P: 0.035% max.