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AssigneeNippon Steel Corporation
InventorsHiroyuki Nakashima, Hideki Oka, Hidemaro Takeuchi, Shigenori Tanaka, Yoshimori Fukuda, Satoshi Akamatsu, Masafumi Miyazaki, Yoshikazu Matsumura
Estimating the term…
In continuous casting a thin carbon cast strip, the scale formed thereon is made thin and made to have a composition suited to working such as cold rolling and pressing. Moreover, an apparatus for inhibiting scale formation is simplified, and the consumption amount of an inert gas is reduced. The cast strip is thus produced efficiently. A carbon steel containing up to 0.5% of C is cooled and solidified by a pair of cooling drums to give a thin cast strip having a thickness up to 10 mm. The cast strip is introduced into a seal chamber, where the strip is held in an Ar gas atmosphere containing up to 5% of oxygen through a temperature region to at least 1,200.degree. C., and the strip is cooled at a rate of at least 10.degree. C./sec through a temperature region to 750.degree. to 800.degree. C., followed by coiling the strip in a coil form with a coiler at a temperature of at least 500.degree. C. and up to 800.degree. C. Furthermore, the atmosphere is formed with a nitrogen gas or exhaust gas. The scale formation is inhibited, and the composition of the scale is controlled by the use of the atmosphere.
In a process for producing a thin cast strip wherein a carbon steel comprising up to 0.5% of C and less than 0.1% of Cr or Cu is cast into a thin cast strip having a thickness up to 10 mm by a continuous casting machine having mold walls which move in synchronization with the cast strip, and the thin cast strip is coiled in a coil form by a coiler, a process for producing a thin cast strip with a reduced surface scale which comprises the steps of holding the thin cast strip, subsequently to casting into the strip in an atmosphere comprising up to 5.0% of oxygen and the balance an inert gas through a temperature region to up to 1,200.degree. C., then cooling the cast strip at a rate of at least 10.degree. C./sec through a temperature region to 800.degree. to 750.degree. C., and coiling the cast strip in a coil form by the coiler.
In a process for producing a thin cast strip wherein a carbon steel comprising up to 0.5% of C and at least 0.1% of Cr or Cu is cast into a thin cast strip having a thickness up to 10 mm by a continuous casting machine having mold walls which move in synchronization with the cast strip, and the thin cast strip is coiled in a coil form by a coiler, a process for producing a thin cast strip with a reduced surface scale which comprises the steps of holding the thin cast strip, subsequently to casting into the cast strip, in an atmosphere comprising up to 7.0% of oxygen and the balance an inert gas through a temperature region to up to 1,200.degree. C., then cooling the cast strip at a rate of at least 10.degree. C./sec through a temperature region to 750.degree. C., and coiling the cast strip in a coil form by a coiler.
Dependencies are inferred from the claim text.