Title:
PROCESS FOR PRODUCING HIGH-STRENGTH STEEL PLATE FOR WELDED STRUCTURE
Document Type and Number:
WIPO Patent Application WO/2011/148755
Kind Code:
A1
Abstract:
A process for efficiently producing a steel plate for welded structures that has excellent matrix toughness and HAZ toughness is provided in which Ti is positively utilized for structural control. An ingot having a composition which has C, Mn, Nb, Ti, and N contents that satisfy given requirements is heated under given conditions and subjected to rough rolling so that each rolling pass satisfies given requirements concerning rolling temperature, draft, and interval between passes, and is subsequently subjected to accelerated cooling at an average rate of cooling in the plate-thickness direction of 5 ºC/s or more. It is preferable that after the rough rolling and before the accelerated cooling, finish rolling should be conducted so that each rolling pass satisfies given requirements concerning rolling temperature, draft, and cumulative draft. After the accelerated cooling, heat treatment may be conducted. Water cooling may be conducted between passes of the rough rolling or of the finish rolling, after the rough rolling, or before the finish rolling.
Inventors:
SHIRAHATA, Hiroyuki (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
白幡 浩幸 (〒71 東京都千代田区丸の内二丁目６番１号新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
UEMORI, Ryuji (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
白幡 浩幸 (〒71 東京都千代田区丸の内二丁目６番１号新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
UEMORI, Ryuji (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
Application Number:
JP2011/060341
Publication Date:
December 01, 2011
Filing Date:
April 21, 2011
Export Citation:
Assignee:
NIPPON STEEL CORPORATION (6-1 Marunouchi 2-chome, Chiyoda-ku Tokyo, 71, 〒1008071, JP)
新日本製鐵株式会社 (〒71 東京都千代田区丸の内二丁目６番１号 Tokyo, 〒1008071, JP)
SHIRAHATA, Hiroyuki (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
白幡 浩幸 (〒71 東京都千代田区丸の内二丁目６番１号新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
新日本製鐵株式会社 (〒71 東京都千代田区丸の内二丁目６番１号 Tokyo, 〒1008071, JP)
SHIRAHATA, Hiroyuki (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
白幡 浩幸 (〒71 東京都千代田区丸の内二丁目６番１号新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
International Classes:
C21D8/02; B21B1/22; B21B3/00; C22C38/00; C22C38/14; C22C38/58
Attorney, Agent or Firm:
SHIGA, Masatake et al. (1-9-2, Marunouchi Chiyoda-k, Tokyo 20, 〒1006620, JP)
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