Alloy tool steel for mfg. cold rolls - where steel has deep hardening properties obtd. by oil quenching, so rolls have long working life

摘要

After hardening and tempering, the rolls have a min. hardness of 60 HRC up to a depth of min. 50 mm below the roll surface; and the rolls also possess good wear resistance. The steel employed to make the rolls contains by wt. 0.7-0.9% C, 0.2-2% Si, 0.2-1% Mn, 2.5-3.5% Cr, 0.7-1.5% Ni, 0.5-2% Mo, 0.1-0.8% V, the remainder being iron and the usual trace impurities. The pref. steel (I) has the compsn. 0.8% C, 0.9% Si, 0.4% Mn, 3% Cr, 1% Ni, 1% Mo, 0.2% V, the remainder being iron and the usual trace impurities. Used e.g. in the mfr. of rolls employed in cold rolling mills for mfg. wide steel strip. High wear resistance is provided so the rolls have very long life.