Indefinite Chill Rolls are having very hard Shell and tough core to have high wear resistance and toughness. DPIC Rolls are manufactured in Static Casting by Double Poured Pouring Process. In this process first shell metal is poured in the chill mould from bottom to top and after that core metal is poured in mould from bottom to top. The rest of molten material is passes throughout.
The structure of these rolls are bainitic or almost martensitic on the surface upto a particular depth.This Characteristic gives a higher hardness and good wear resistance.As per the requirement of party, Shell and Core Iron Compositions are adjusted depending upon the hardness. In these rolls drop of hardness is very small up to the Shell depth. These rolls are available in hardness range up to 70 – 85 at shore.The core metal may be lamellar Cast Iron or Nodular Cast Iron depending on the requirement of journal strength and toughness. Especially these rolls are used in Finishing and Continuous Stand of the Rolling Mills.
| Grade | C | Mn | Si | P | S | Ni | Cr | Mo | UTS Kgmf/mm² |
|---|---|---|---|---|---|---|---|---|---|
| 50-60 | 3.00/3.20 | 0.60/0.90 | 1.10/1.50 | 0.15Max. | 0.06Max. | 1.50/1.80 | 0.80/1.20 | 0.25/0.35 | 35-45 |
| 60-70 | 3.00/3.30 | 0.60/0.90 | 1.00/1.50 | 0.15Max. | 0.06Max. | 1.50/2.50 | 0.80/1.20 | 0.25/0.40 | 35-45 |
| 70-75 | 3.10/3.50 | 0.60/0.90 | 1.00/1.30 | 0.15Max. | 0.06Max. | 2.00/3.00 | 0.80/1.20 | 0.30/0.45 | 35-45 |