Title:
HIGH-STRENGTH PART AND PROCESS FOR PRODUCING THE SAME
Document Type and Number:
WIPO Patent Application WO/2006/030971
Kind Code:
A1
Abstract:
A high-strength part that excels in hydrogen embrittlement resistance and strength after high-temperature forming; and a process for producing the same. The atmosphere in a heating furnace before forming is regulated to one of ≤ 10% hydrogen volume fraction and ≤ 30°C dew point. As a result, the amount of hydrogen penetrating in a steel sheet during heating is reduced. After forming, there are sequentially carried out quench hardening in die assembly and post-working. As the method of post-working, there can be mentioned shearing followed by re-shearing or compression forming of sheared edge portion; punching with a cutting blade having a gradient portion at which the width of blade base is continuously reduced; punching with a punching tool having a curved blade with a protrudent configuration at the tip of cutting blade part, the curved blade having a shoulder portion of given curvature radius and/or given angle; fusion cutting; etc. Consequently, the tensile residual stress after punching is reduced and the performance of hydrogen embrittlement resistance is improved.
Inventors:
KUSUMI KAZUHISA (JP)
SATO HIRONORI (JP)
ABE MASAYUKI (JP)
FUJITA NOBUHIRO (JP)
SUZUKI NORIYUKI (JP)
HAYASHI KUNIO (JP)
NAKAJIMA SHINYA (JP)
MAKI JUN (JP)
OOGAMI MASAHIRO (JP)
KANDA TOSHIYUKI (JP)
TAKAHASHI MANABU (JP)
TAKAHASHI YUZO (JP)
SATO HIRONORI (JP)
ABE MASAYUKI (JP)
FUJITA NOBUHIRO (JP)
SUZUKI NORIYUKI (JP)
HAYASHI KUNIO (JP)
NAKAJIMA SHINYA (JP)
MAKI JUN (JP)
OOGAMI MASAHIRO (JP)
KANDA TOSHIYUKI (JP)
TAKAHASHI MANABU (JP)
TAKAHASHI YUZO (JP)
Application Number:
PCT/JP2005/017441
Publication Date:
March 23, 2006
Filing Date:
September 15, 2005
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
KUSUMI KAZUHISA (JP)
SATO HIRONORI (JP)
ABE MASAYUKI (JP)
FUJITA NOBUHIRO (JP)
SUZUKI NORIYUKI (JP)
HAYASHI KUNIO (JP)
NAKAJIMA SHINYA (JP)
MAKI JUN (JP)
OOGAMI MASAHIRO (JP)
KANDA TOSHIYUKI (JP)
TAKAHASHI MANABU (JP)
TAKAHASHI YUZO (JP)
KUSUMI KAZUHISA (JP)
SATO HIRONORI (JP)
ABE MASAYUKI (JP)
FUJITA NOBUHIRO (JP)
SUZUKI NORIYUKI (JP)
HAYASHI KUNIO (JP)
NAKAJIMA SHINYA (JP)
MAKI JUN (JP)
OOGAMI MASAHIRO (JP)
KANDA TOSHIYUKI (JP)
TAKAHASHI MANABU (JP)
TAKAHASHI YUZO (JP)
International Classes:
B21D28/00; B21D28/14; C21D1/74; C21D9/46; C22C38/00; C22C38/04; C22C38/38
Domestic Patent References:
| WO2006006742A1 | 2006-01-19 |
Foreign References:
| JP2004124221A | 2004-04-22 | |||
| JPH01128915U | 1989-09-01 | |||
| JP2004083927A | 2004-03-18 | |||
| JPH11333530A | 1999-12-07 | |||
| JPH07214193A | 1995-08-15 | |||
| JPH06238361A | 1994-08-30 | |||
| JP2000301220A | 2000-10-31 | |||
| JPH10263720A | 1998-10-06 | |||
| JPH0475622U | 1992-07-02 | |||
| JP2004027290A | 2004-01-29 | |||
| JP2003181549A | 2003-07-02 | |||
| JP2004176181A | 2004-06-24 | |||
| JP2003138343A | 2003-05-14 | |||
| JP2003328031A | 2003-11-19 | |||
| JP2004124221A | 2004-04-22 | |||
| JPH06238361A | 1994-08-30 | |||
| JP2003181549A | 2003-07-02 | |||
| EP1767286A1 | 2007-03-28 |
Other References:
"X-Ray Stress Measurement Method Standard (2002 Edition)- Ferrous Metal Section", JAPAN SOCIETY OF MATERIALS SCIENCE, March 2002 (2002-03-01)
Attorney, Agent or Firm:
Aoki, Atsushi (Toranomon 37 Mori Bldg. 5-1, Toranomon 3-chom, Minato-ku Tokyo, JP)
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