SGI Rolls or Spheroidal Graphite Iron Rolls, are cast rolls made from ductile iron in which the graphite is present in a nodular or spheroidal form, rather than the flake form found in grey iron. This microstructure provides a unique combination of strength, toughness, and thermal resistance, making SGI rolls ideal for roughing stands and early passes in rolling mills.

SGI rolls typically contain carbon, silicon, manganese, and small amounts of magnesium, which transforms the graphite into a nodular shape during solidification. This structure gives SGI rolls their ductile nature and resistance to cracking under heavy loads. They are especially suitable for applications where a balance between cost, durability, and performance is required.

• Good wear and impact resistance
• Excellent thermal fatigue resistance
• Cost-effective and easily regrindable

• High Strength & Toughness SGI rolls possess excellent mechanical strength and toughness, making them ideal for heavy-duty roughing operations and high-impact zones.
• Good Wear Resistance Thanks to their balanced composition and spheroidal graphite structure, SGI rolls offer moderate wear resistance suitable for primary deformation passes.
• Thermal Shock Resistance SGI rolls can withstand sudden temperature changes without cracking, making them well-suited for intermittent cooling and heating cycles in roughing mills.
• Crack Resistance The spheroidal graphite structure helps absorb stress and resist crack propagation, ensuring longer operational life under mechanical loads.
• Cost-Effective SGI rolls are economical compared to alloy steel or HSS rolls, providing a good balance between performance and affordability for early rolling stages.
• Easy Machinability SGI rolls are easier to machine and recondition compared to harder materials, leading to lower maintenance and regrinding costs.
• Customizable Grades Various grades can be tailored based on hardness, strength, and wear properties to suit specific rolling mill applications and product requirements.