Application of a High Chromium Steel to Roughing Work Rolls for Hot Strip Mills

Abstract

High-chromium (Hi-Cr) iron rolls have good wear resistance, but have certain disadvantages in their application to roughing mills. The influence of C and Cr contents on material and mechanical properties were examined.
The dendritic structure of the material changes with C and Cr contents, with the structure of lower C and Cr steel being larger than that of higher C and Cr iron. Hot hardness and wear resistance do not depend on C and Cr contents, while the mechanical wear of these materials decreases with increasing hardness. The thermal shock resistance decreases with decreasing Cr content.
Using Hi-Cr steel rolls instead of Hi-Cr iron rolls in a hot strip roughing mill, accidental slippage was prevented by their rougher surface and better performance obtained by increasing hardness.