Stretch Reducing Rolls.
Stretch reducing mills enable elongation; change in the diameter and, depending on the design, reduction of the tube wall thickness without the use of internal tooling.
Centrifugally Cast Bi-Metal Rolls
S+C B&J supplies rolls made from centrifugally cast bi-metal consisting of an alloyed outer shell and a grey iron soft core. These materials have been developed to meet specific requirements and offer advantages over the lower grade chilled cast irons. With these simpler chilled cast irons the chill depth comprises 8-10% of the barrel diameter and even though the chilled shell is hard it drops significantly in the transition area.
ADVANTAGES OF THE CENTRIFUGALLY CAST BI-METAL ROLLS MADE BY S+C ARE:
– High integrity – no porosity
– Choice of composition and depth of shell
– Hardness consistent throughout depth of shell
– High resistance to crack propagation
– High thermal conductivity
– Good fire cracking resistance
– Improved toughness due to grey iron core
– Forged Tool Steel Stretch Reducing Rolls
In addition to rolls made from cast materials, forged rolls in the tool steel Märker® ZESEK, offering high wear resistance and improved toughness, have proved successful, particularly for thick walled tubes. These rolls are specially heat treated to meet the specific requirements of this hot rolling process.