| 摘要 |
PURPOSE:To produce a chilled material of superior abrasion resistance for rolling rolls by die-casting the molten cast iron contg. Ni, Cr and Mo to a roll by means of centrifugal casting then subjecting the same to heat treatment under specific conditions. CONSTITUTION:Molten metal of the low alloy cast iron contg. 2.8-3.5% C, 0.3- 0.9% Si, 0.3-1.2% Mn, 1.5-3.5% Ni, 2.0-5.0% Cr and 0.2-1.0% Mo is cast in dies by centrifugal casting, whereby a roll-like chilled material is produced. This is heated to the temp. to 950-up to 50 deg.C below solidus temp. to be made into two phase structure of cementite +gamma, after which it is quickly cooled down to 450- 550 deg.C by spray water cooling. Next, it is further reheated to 780-860 deg.C, to grain the matrix of the structure, whereby chilled material of superior abrasion resistance having the matrix of high surface hardness and superior toughness for rolling rolls may be produced. |
