Title:
ROLLED STEEL BAR FOR HOT FORGING
Document Type and Number:
WIPO Patent Application WO/2013/077182
Kind Code:
A1
Abstract:
A high-strength untempered hot-forged component having a tensile strength of 900 MPa or higher and an endurance ratio in the perpendicular direction of 0.47 or greater can be obtained by using, as a raw material, a rolled steel bar for hot forging comprising 0.27-0.37% of C, 0.30-0.75% of Si, 1.00-1.45% of Mn, 0.008% or more and less than 0.030% of S, 0.05-0.30% of Cr, 0.005-0.050% of Al, 0.200-0.320% of V, and 0.0080-0.0200% of N, with the remainder comprising Fe and impurities, wherein said impurities include P≤0.030%, Ti≤0.0040%, O≤0.0020%, and [1.05≤C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S≤1.18]. The rolled steel bar for hot forging as the raw material may contain one or more of Cu, Ni, and Mo in place of a portion of said Fe, but in this case, the following condition needs to be satisfied: [1.05≤C+(1/10)Si+(1/5)Mn+(5/22)Cr+1.65V-(5/7)S+(1/5)Cu+(1/5)Ni+(1/4)Mo≤1.18].
Inventors:
HIGASHIDA MASASHI (JP)
MATSUMOTO HITOSHI (JP)
MATSUI NAOKI (JP)
NEISHI YUTAKA (JP)
MAKINO TAIZO (JP)
MATSUMOTO HITOSHI (JP)
MATSUI NAOKI (JP)
NEISHI YUTAKA (JP)
MAKINO TAIZO (JP)
Application Number:
PCT/JP2012/078789
Publication Date:
May 30, 2013
Filing Date:
November 07, 2012
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C22C38/24; C22C38/46; C21D8/06
Foreign References:
| JP2000239782A | 2000-09-05 | |||
| JPH09143610A | 1997-06-03 | |||
| JP2004137542A | 2004-05-13 | |||
| JP2010007143A | 2010-01-14 | |||
| JPH0892687A | 1996-04-09 | |||
| JPH06287677A | 1994-10-11 |
Other References:
See also references of EP 2784169A4
Attorney, Agent or Firm:
SUGIOKA, Kanji et al. (JP)
Sugioka Miki 2 (JP)
Sugioka Miki 2 (JP)
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Claims: