PURPOSE: To reduce surface defects caused on a stainless alloy steel slab by cracking during hot rolling by specifying the amount of sol. Al added to the stainless alloy steel having a specified composition and by regulating the concn. of O2 in the atmosphere in a furnace when the slab is heated.
CONSTITUTION: A stainless alloy steel is provided with a composition contg., by weight, 0.001W0.20% C, 0.10W5.0% Si, 0.1W11.0% Mn, ≤0.050% P, ≤0.020% S, 11.0W30.0% Cr, 2.0W3.0% Ni, 0.001W0.060% N, ≤0.015% O, ≤5.0% Mo, ≤3.0% Cu, ≤1.0% Nb, ≤0.05% Ti, ≤0.10% Zr, ≤0.06% Ca and ≤0.10% Sn and/or ≤0.05% B. The concn. of O2 in the atmosphere in a furnace is regulated to 0.5W5.0% and a slab of the steel is heated in the atmosphere. Thus, S and O2 in the steel are made harmless, so the occurrence of surface defects due to cracking during hot rolling is prevented.
KOBAYASHI MAKOTO
KAKIUCHI HIROYUKI
YAGISHIMA AKIYA
YOSHIOKA KEIICHI
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