PURPOSE: To manufacture a low-carbon sulfur free cutting steel with superior machinability and surface properties by controlling the oxygen content of a steel to a specified low range in accordance with the rolling ratio of a product and casting the resulting steel by a continuous casting method.
CONSTITUTION: In the manufacture of a sulfur free cutting steel contg. ≤0.15% C, ≤0.03% Si, 0.70W1.50% Mn, 0.040W0.120% P and 0.24W0.35% S, the oxygen content of a steel is controlled to 70W200ppm in accordance with the rolling ratio of a product, and this molten steel is cast by a continuous casting method. By this method a spindle-shaped MnS inclusion giving high machinability is obtd., and low-carbon sulfur free cutting steel with superior surface properties is manufactured.
UESUGI HIROYUKI
YAMAMOTO YOSHIHARU
WADA YOSHINOBU
SHINJIYOU YUTAKA
ARAKI MASAKAZU
