Title:
HOT-ROLLED STEEL SHEET, FORGED STEEL PART AND PRODUCTION METHODS THEREFOR
Document Type and Number:
WIPO Patent Application WO/2018/179389
Kind Code:
A1
Abstract:
A hot-rolled steel sheet, wherein: the steel sheet chemical composition, in mass%, is C: 0.020-0.070%, Si: 0.05-1.70%, Mn: 0.60-2.50%, Al: 0.010-1.000%, N>0-0.0030%, P≤0.050%, S≤0.00 5%, Ti: 0.015-0.170%, Nb: 0-0.100%, V: 0-0.300%, Cu: 0-2.00%, Ni: 0-2.00%, Cr: 0-2.00%, Mo: 0-1.00%, B: 0-0.0100%, Mg: 0-0.0100%, Ca: 0-0.0100%, REM: 0-0.1000%, Zr: 0-1.000%, Co: 0-1.000%, Zn: 0-1.000%, W: 0-1.000%, Sn: 0-0.050%, balance: Fe and impurities; the steel sheet metal structure is, in area%, ferrite: 5-70%, bainite: 30-95%, retained γ ≤2%, martensite ≤2%, pearlite ≤1%; ferrite + bainite ≥95%; the number density of micro Ti deposits in the ferrite grains is 1.0×1016-50.0×1016/cm3; the mean equivalent circular diameter of the TiN deposits in the steel sheet is 1.0-10.0 µm; the mean value for the shortest distance between adjacent TiN deposits is at least 10.0 µm; and the standard deviation for nano-hardness is 1.00 GPa or less.
More Like This:
Inventors:
YOKOI TATSUO (JP)
YOSHIKAWA NOBUO (JP)
YONEMURA SHIGERU (JP)
OOTSUKA KAZUYA (JP)
YOSHIKAWA NOBUO (JP)
YONEMURA SHIGERU (JP)
OOTSUKA KAZUYA (JP)
Application Number:
PCT/JP2017/013747
Publication Date:
October 04, 2018
Filing Date:
March 31, 2017
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C21D9/46; C22C38/58
Domestic Patent References:
| WO2011135997A1 | 2011-11-03 |
Foreign References:
| JP2009275238A | 2009-11-26 | |||
| JP2011012308A | 2011-01-20 | |||
| JP2002161340A | 2002-06-04 | |||
| JP2007009322A | 2007-01-18 | |||
| JP2002105595A | 2002-04-10 | |||
| JP2002322540A | 2002-11-08 | |||
| JP2002322541A | 2002-11-08 |
Other References:
See also references of EP 3604583A4
Attorney, Agent or Firm:
BRIGHTAS IP ATTORNEYS (JP)
Download PDF: