GST-GT Graphitic Supermit Alloy Steel Rolls
GST-GT Supermit Alloy Steel is a high carbon, high alloy steel manufactured by means of a special multi-stage heat treatment in order to develop the combination of hardness, toughness and wear resistance required for a variety of heavy duty, heavy abrasive-wear applications. The structure produced consists of well broken up and dispersed carbides in a Pearlitic-Bainitic matrix with higher %C grades exhibiting an increasingly Bainitic matrix. Above Carbon levels of %1.75, an increasing amount of semi-continuous carbide is present complementing the hardness and wear resistance imparted by the highly alloyed matrix. Because of its high hardenability, GST-GT Supermit Alloy Steel shows no fall off in hardness with increasing depth.
The higher carbide content and tough, hard matrix makes GST-GT Supermit Alloy Steel particularly suitable for section rolling where resistance to abrasive wear is required. A very high surface finish is maintained for the duration of each mounting as metallographic structure is consistent until discard. GST-GT is suitable for intermediate and finishing stands especially and excels where deep grooves are involved and high wear resistance is required. GST-GT succeeds where Nodular Chill Irons are not able to provide the required wear resistance at depth and past the chill depth. Experience in many mills has shown that GST-GT Supermit Alloy Steel gives substantially higher outputs than conventional materials.
GST-GT Graphitic Supermit Alloy Steel rolls are supplied with a controlled amount of well dispersed graphite in their microstructure. This flake graphite promotes fine and more controlled fire-crack pattern. GST-GT is recommended where a combination of wear resistance, toughness and tolerance to adverse thermal conditions are required. Free graphite reduces the impact of thermal shocks by means of improved dissipation of heat from the surface to the core during the heating cycle and from the core to the surface during the cooling cycle of the roll.