PURPOSE: To produce the outer shell in high hardness beyond a specified hardness, by treating a compound roll consisting of outer shell made of high hardness high Cr material and inner shell made of tough cast iron material, under sub-zero treatment.
CONSTITUTION: An outer shell 1 consisting of 2.3W3.0% C, 0.4W1.0% Si, 1.5W 3.0% Ni, 13W20% Cr, 1.5W3.5% Mo, 0.5W1.5% Mn and the substantial balance of Fe is centrifugally cast, and the molten metal of inner shell 2 consisting of 2.8W 3.4% C, 2.5W3.0% Si, 0.2% Cr or less, one or more kinds of Mn, Ni and Mo totaling to 2.5% or less, and the substantial balance of Fe is poured into the outer shell 1 before its interior is solidified or after it is solidified. Thus, an integral compound roll having the outer and inner shells completely deposited together is obtained. This compound roll is treated by sub-zero treatment below 0°C to make martensite structure, so that the outer shell is made to a high hardness above 80 Hs.
| JP2000054080 | ROLL FOR HOT ROLLING |
| JPH0985487 | CALIBER ROLL FOR HOT WORKING |
| JPH07265915 | COMPOSITE ROLL |
NAKAGAWA YOSHIHIRO
HASHIMOTO TAKASHI
| JPS5256012A | 1977-05-09 |