PURPOSE: To produce a mild blackplate of Class T-3 having excellent corrosion resistance by coiling low carbon Al killed steel contg. specified contents of C, solAl, and total N at low temp. after hot rolling then subjecting said steel to continuous annealing and overaging under adequate conditions.
CONSTITUTION: The continuously cast ingot of the low carbon Al killed steel contg. 0.02W0.09% C, 0.003W0.02% solAl, and ≤0.0040% total N is hot rolled and is coiled at 500W580°C. Said steel is subjected to pickling followed by cold rolling. The cold rolled plate is held for ≥20sec at ≥680°C in a continuous annealing furnace and is cooled down to ≤500°C at 10W500°C/sec cooling rate. After the plate is further held for ≥20sec at 350W500°C, it is cooled down to a room temp. Such steel plate is subjected to prescribed skin pass rolling. The mild blackplate which has good descaling property, is as mild as Class T-3 and is highly resistant to corrosion is obtained by the above-mentioned method.
KUKUMINATO HIDEO
IZUMIYAMA SADAO
YAGISHIMA AKIYA
OBARA TAKASHI
MOCHIZUKI KAZUO
| JPS50121118A | 1975-09-22 |
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