Title:
STEEL COMPONENT FOR HIGH-TEMPERATURE CARBURIZING WITH EXCELLENT SPALLING STRENGTH AND LOW-CYCLE FATIGUE STRENGTH
Document Type and Number:
WIPO Patent Application WO/2015/147067
Kind Code:
A1
Abstract:
This steel component for high-temperature carburizing which has excellent spalling strength and low-cycle fatigue strength and which is useful as a material for power transmission components, etc., is provided by suitably adjusting the chemical component composition, setting the average C concentration up to a depth of 0.05mm from the surface to 0.50% or greater, and controlling the average circle equivalent diameter Dm(μm) and the number density Nm (number/mm2) of MnS in a non-carburized portion, the average circle equivalent diameter Dt(μm) and the number density Nt (number/mm2) of TiN in the non-carburized portion, the Vickers hardness Hs (HV) at a position 0.05mm deep from the surface and the Vickers hardness Hi (HV) at the non-carburized portion measured with a test force of 300gf, and the effective hardened layer depth ECD (mm) so as to satisfy the expressions A=exp{Dm/10+Nm1/2/50}×exp{Dt/15+Nt1/2/50}, B=exp{Hs/650+ECD1/2+Hi/250}, C=exp[Hs/650-ECD-{(0.89×Hi-202.16)/250}2], 3.7×A-0.47×B+1.14≦0, and C≧0.66.
Inventors:
SHUDO TAKEHIRO
SHINDO YOSUKE
FUJITA MANABU
SHINDO YOSUKE
FUJITA MANABU
Application Number:
PCT/JP2015/059152
Publication Date:
October 01, 2015
Filing Date:
March 25, 2015
Export Citation:
Assignee:
KOBE STEEL LTD (JP)
International Classes:
C22C38/00; C21D1/06; C22C38/38; C22C38/58; C21D8/00
Domestic Patent References:
| WO2012108460A1 | 2012-08-16 |
Foreign References:
| JP2012072427A | 2012-04-12 | |||
| JP2006028568A | 2006-02-02 | |||
| JP2007162128A | 2007-06-28 | |||
| JP2007217761A | 2007-08-30 | |||
| JP2010285689A | 2010-12-24 |
Attorney, Agent or Firm:
UEKI, Kyuichi et al. (JP)
Hisakazu Ueki (JP)
Hisakazu Ueki (JP)
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