Abstract:8Cr4MoV low alloyed forged super-deep hardening layer cold work roll steels were studied in laboratory containing about 4%Cr, 0.8%C, and appending a little of N and Re in it individually or together. After smelt in 50 kg vacuum induction furnace primarily, then forged, quenched and tempered in turn, the steels′ mechanics performances, microstructures and hardenability by end quenching test were compared each other, the better was put into trial-manufacture of super-deep hardening layer cold work rolls of 1700㎜body length for 4 H tandem cold mill in Cold Strip Mills WISCO. With quenched by 50/250Hz induction hardening machine, the rolls had uniform hardness on the body surface, and proved their resistance to wear higher, having longer service life over 1.6 times of Cr2 conventional cold work roll, deeper hardening layer depth corresponding to Cr5 super-deep hardening layer cold work roll, and no spalling, better resistance to accident.