Introduction: This grade is characterised by nodular graphite and carbides arranged in a pearlitic matrix. Its properties are similar to Alloy Indefinite Chill except the graphite structure is changed from flake shapes to spheroidal forms. This gives the smallest surface area to volume which results in and increase resistance to crack propagations. The internal notch effect of nodular graphite is small.

Possible Alloyings: Variant of perlite: In casting production, elements added to gray iron can be classified into four principal categories--graphitizers, carbide stabilizers, pearlite stabilizers and pearlite refiners.

SG Pearlitic rolls will demonstrate much higher strength. The Indefinite Chill characteristics also gives the rolls good hardness penetration. SG Pearlitic rolls are suitable for many purposes, and can meet a wide range of applications. In addition vaious SG Pearlitic grades have been introduced: SGP grdes alloyed with Cr to achieve a deep penetration of carbides. These graeds have a lower hardness drop and good wear resistance properties and is recommended for rolls with deep grovves. SGP grades alloyed with Mo and subjected to high temperature heat treatment. These grades have an excelllent resistance to fire cracking properties along with good strength. The impace resistance is also increased over that of flake graphite iron.

Properties: Thanks to its higher content of Ni and Mo alloys, pearlite, basinite and martensite matrixes with excellent performance are produced. The graphite si spherical form, demonstraing good heat transfer property and high tensile strength. Through changing the struture into basinite of marensite matrix, chemical compostion of needly-like spherical iron of heat treatment, a dense reticular primary cementite with high wear-resistance is produced.

Application: Various types of continuous rough intermediate and finish mills for processing bars, sections and strips. Used as the secondary finishing and back rolls. Also suitable for use on stainless-steel strip hot mill. Roughing and intermediate rolls for slabbing and blooming mills. Roughing, intermediate and finishing for rail and structural mils. Finishing for wire rod and narrow strip mils.