Spheroidal Graphite (Nodular) S.G. Cast Iron Rolls
These Rolls are structurally characterized by nodular graphite as against flack graphite by Nodularizing in the normal cast iron through Magnesium Treatment, Indefinite Chill type material, but with the Graphite in Nodular form instead of flake and having alloyed with higher percentage of Carbon along with Nickel, Molybdenum and Chrome. So these rolls have a much higher Mechanical Strength and allow the use of an iron Rolls in applications which would re-present too high a duty for a flake iron quality due to internal ‘notch effect’ of nodular graphite is relatively small. The microstructure consists of a Ferritic, Pearlitic and Bainitic Metric with minor traces of cementite (Fe3C) but different forms of free Graphite (Flake & Nodular). These rolls are very much suitable for the rolling of row products with vide range of applications due to its hardness penetration; good wear resistance and tough necks. These rolls are available in three different grades; (I) SGI Ferritic , (II) SGI Pearlitic & (III) SGI Bainitic Accicular.
| Chemical Composition (Range) | Physical Properties | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C% | Mn% | Si% | Cr% | Ni% | Mo% | V% | S% | P% | Hardness Range (Shore 0C) | Tensile Strength (N/mm2) | Bending Resistance N/mm2) | |||
| 3.00 3.60 | 0.30 0.80 | 1.20 2.50 | 0.50 1.20 | 1.50 3.50 | 0.30 1.10 | 0.20 Max | 0.015 Max | 0.10 Max | 500C - 750C | 400 – 800 | 700 – 1350 | |||
Product Application
Application of S.G.I.-Pearlitic is very suitable according to Hardness & Chemical Composition range as per below:
| Rolling Mills | Mill - Type | Stands - Position | Pass - Condition | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Plate, Sheet, Billet & Sheet Bar | 2 & 3 Hi or Universal | Only on Finishing- stand | In case low reduction, light groove pass & low or high RPM as well as short rolling length. | |||||||||
| TMT, Wire-rod, Medium & Light Section Mill | Roughing, Intermediate & Finishing- stand | |||||||||||
| Round & Bar Mill | Intermediate & Finishing-stand | |||||||||||
