PURPOSE: To manufacture a hot-rolled high-tension steel plate having high strength and cold workability comparable to those of a conventional high Si and high Mn steel plate by rolling a low Si and low Mn steel billet at a low temp. and coiling the resulting plate at a specified temp.
CONSTITUTION: A cast steel billet contg. 0.02W0.25% C, <0.14% Si, <0.02W 0.28% Mn, <0.025% P, <0.005% S and 0.01W0.10% sol. Al is manufactured. The billet may further contain one or more among at least one among <0.05% each of Nb, V and Ti (i), <0.0100% Ca (ii) and <0.0050% B (iii). The billet is hot rolled to a plate, and the hot rolling is finished at Ar3+50°CW650°C. The plate is rapidly cooled at ≥50°C/sec cooling rate and coiled at ≤450°C. A hot- rolled high-tension steel plate having superior strength and cold workability is obtd. while using said small amounts of added elements such as Si and Mn.
NAGAO NORIAKI
TAKAHASHI MASASHI
HINO TAKAO
| JPS58130221A | 1983-08-03 | |||
| JPS5684422A | 1981-07-09 | |||
| JPS5544590A | 1980-03-28 | |||
| JPS5395121A | 1978-08-19 |
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