SG-X Ni Extra Ferritic Nodular Iron Rolls
SG-X Ni Extra Ferritic nodular iron material further develops properties associated with SG Acicular Chill qualities. Typically, the graphite nodules are surrounded by a layer of ferrite giving a characteristic “bull's eye” effect.
The structure of the matrix in the acicular phase is bainitic and these grades are very highly alloyed and heat treated. In all grades, a significant amount of ferrite surrounds each graphite nodule and carbide formation is suppressed.
The material has superb mechanical properties and provides good resistance to fire-cracking as well as thermal failure. This material is fine-tuned by precise control of alloying elements and is subjected to a high temperature multi-stage heat treatment.
The high strength and thermal resistance of SG-X Ni Ferritic make it an ideal roll material for use in Roughing applications of long and flat product mills where thermal duty is severe as well as Seamless Tube mills where already high mechanical loads are compounded by stresses caused by varying circumferential velocities and resulting slippage.
The rolls have virtually no hardness drop and hardness penetration is excellent, permitting SG-X Ni Ferritic to be used in all types of pass profiles. The higher alloyed SG-X Ni Ferritic grades particularly, combine high strength, toughness and wear resistance and can be considered as an alternative to forged steel in various applications with a substantial improvement in performance.
Because of the nodular form of the graphite, the strength of SG-X Ni Ferritic is quite high and the rolls can be used in relatively heavy duty applications.
All rolls of this material are statically single poured.