Cr, and casting method of the twin-roll continuous casting machine of Ni containing iron-base alloy

摘要

PURPOSE:To surely prevent the development of crack on a cast strip surface and to produce the Cr and Ni-contained steel strip having excellent surface characteristic by specifying composition of molten steel, controlling cooling velocity in solidified shell and ferritic quantity in the cast strip to the specific value or more. CONSTITUTION:As the iron-base alloy, the material having composition composed of =0.20wt.% C, =5.00wt.% Si, =3.00wt% Mn, =50wt.% Ni, 1-50wt.% Cr, =0.3wt.% N and the balance mainly Fe and satisfying condition of Creq/Nieq2.05 to the Cr and Ni equivalent ratios, is used. The cooling velocity of strip is controlled to 50-450 deg.C/sec in the range from the strip surface to 0.2 mm depth. Further, the average residual ferritic ratio to thickness direction of the strip, is made to =2.0%. Wherein, Cr equivalent ratio: (%Cr)+(%Mn)+1.5(%Si), Ni equivalent ratio: (%Ni)+30 (%C)+0.5(%Mn).