Tuesday, September 13, 2016

SPUN Cast (Centrifugal) Rolls and STATIC Cast Rolls

For more information check  SARJIT ROLLS

Spun cast Rolls
Static cast Rolls

Bainitic to martensic, highly recommended for finishing and continuous stands
Pearlitic to bainitic recommended for roughing and intermediate stands

Easily available as all parameters can be controlled
Difficult as most of the parameters cannot be controlled

Uniformity in hardness with depth i.e. due to centrifugal process
Hardness reduces drastically with depth i.e. characteristic of a pearlite structure

Pass life
Ideally 20% higher performance to that of its static counterpart

Easy as there is an accurate distinction between shell and core and no hard journals
 Easy to medium, sometimes could lead to very hard journals due to presence of excessive alloys

Chill depth maintenance

Accurately maintainable
Hard to standardize, Varies with changes in pouring temperature and viscosity of the metal

Shrinkage in journals
Controllable, as softer core metal has less shrinkage possibilities
Shrinkage in journals is an issue due presence of hard alloy metal in journal

Impurities and blow holes on the surface
Property of centrifugal casting to reject all impurities and blow holes to the surface which are removed during machining
Possibility of blow holes and impurities on the shell surface

Strength of barrel and journals
Fine grain structure, prone to chipping and spalling in case no proper bonding
Equi-axed structure, high in strength due to slow cooling, recommended for high pressures of the roughing stands