Title:
STRAIN-INDUCED-TRANSFORMATION COMPOSITE-STRUCTURE STEEL PLATE AND METHOD OF MANUFACTURING SAME
Document Type and Number:
WIPO Patent Application WO/2017/022027
Kind Code:
A1
Abstract:
A strain-induced-transformation composite-structure steel plate according to the present invention has a predetermined chemical composition; a structure thereof at 1/4 of the plate thickness contains, in terms of area proportions, 50 to 85 % polygonal ferrite, 3 to 10 % residual austenite, 5 to 47 % bainite, and 1% or less fresh martensite and tempered martensite in total; and 0.01 < Ex.C/fsd ≤ 0.015 is satisfied, wherein the aforementioned structure contains TiC-containing precipitates in an amount equal to or greater than 1×1016 /cm3, the average particle size of the residual austenite is 1.0 to 5.0 μm in the circle-equivalent diameter, the average closest distance of the residual austenite is 3.0 to 10.0 μm, and the average size of the precipitates is equal to or less than 3 nm.
Inventors:
YOKOI TATSUO (JP)
SHUTO HIROSHI (JP)
KANZAWA YUUKI (JP)
SUGIURA NATSUKO (JP)
SHUTO HIROSHI (JP)
KANZAWA YUUKI (JP)
SUGIURA NATSUKO (JP)
Application Number:
PCT/JP2015/071848
Publication Date:
February 09, 2017
Filing Date:
July 31, 2015
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C21D9/46; C22C38/54
Domestic Patent References:
| WO2014051005A1 | 2014-04-03 |
Foreign References:
| JP2007146209A | 2007-06-14 | |||
| JP2004002969A | 2004-01-08 |
Other References:
See also references of EP 3330395A4
Attorney, Agent or Firm:
SHIGA Masatake et al. (JP)
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