Title:
ROLLED STEEL BAR FOR HOT FORGING
Document Type and Number:
WIPO Patent Application WO/2017/213166
Kind Code:
A1
Abstract:
This rolled steel bar for hot forging includes, in mass%, 0.39-0.55% of C, 0.10-1.0% of Si, 0.50-1.50% of Mn, 0.05-0.50% of Cr, 0.01-0.10% of Mo, 0.05-0.40% of V, 0.150-0.250% of Ti, 0.005-0.050% of Al, and 0.0020-0.020% of N, and satisfies formulae (1) and (2), wherein: the total area ratio of polygonal ferrite and pearlite is 90% or more; the total content (mass%) of Mo included in precipitates accounts for 50% or more of the total Mo content (mass%) in the steel; and the total number of precipitates having a circle-equivalent diameter of 5-100 nm in the polygonal ferrite accounts for 80% or more of the total number precipitates having a circle-equivalent diameter of 3-1000 nm. 0.60≤C+0.2Mn+0.25Cr+0.75V+0.81Mo≤1.00 (1) 0.12C+0.35Mn+0.42Cr+Mo-0.08Si≤0.70 (2)
Inventors:
TAKASUGA MOTOKI (JP)
MIYAKOSHI YUSUKE (JP)
HASEGAWA TATSUYA (JP)
MIYAKOSHI YUSUKE (JP)
HASEGAWA TATSUYA (JP)
Application Number:
PCT/JP2017/021072
Publication Date:
December 14, 2017
Filing Date:
June 07, 2017
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C22C38/60; C21D8/06
Foreign References:
| JPH11199967A | 1999-07-27 | |||
| JP2014025105A | 2014-02-06 | |||
| JP2015025162A | 2015-02-05 |
Attorney, Agent or Firm:
ASCEND IP LAW FIRM (JP)
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