Title:
A high intensity hotpress member and a manufacturing method for the same
Document Type and Number:
Japanese Patent JP6004138
Kind Code:
B2
Abstract:
Provided are a high-strength hot-pressed part and a method for manufacturing the part. A raw material is a steel sheet obtained by heating a cold-rolled steel sheet having a chemical composition containing, by mass%, C: 0.090% or more and less than 0.30% and Mn: 3.5% or more and less than 11.0% at a temperature in a temperature range equal to or higher than the Ac1 transformation temperature and 850°C or lower, by holding the heated steel sheet at the temperature for 100 seconds or more and 48 hours or less, and by cooling the steel sheet held at the temperature. The raw material is subjected to a heating process in which the raw material is held at a temperature in a temperature range of 800°C to 1000°C for 600 seconds or less and to a hot press forming process in which the heated material is subjected to press forming and quenching at the same time by using a forming tool in order to obtain a hot-pressed part having a specified shape. With this, it is possible to obtain a high-strength hot-pressed part having a microstructure including 3.0% or more of a retained austenite phase and the balance being a martensite phase and tensile properties represented by a tensile strength TS of 1500 MPa or more and a uniform elongation uEl of 6.0% or more. Also, in the case where the cold-rolled steel sheet to be used is a steel sheet having a Zn-based coating layer or an Al-based coating layer on the surface thereof, since it is possible to inhibit the generation of scale on the surface of the part, there is an increase in the productivity of a hot-pressed part.
Inventors:
Nakagawa Koichi
Takeshi Yokota
Kazuhiro Seto
Takeshi Yokota
Kazuhiro Seto
Application Number:
JP2016503265A
Publication Date:
October 05, 2016
Filing Date:
October 05, 2015
Export Citation:
Assignee:
jfe Steel Corporation
International Classes:
C22C38/00; B21D22/20; C21D1/18; C21D9/00; C22C38/06; C22C38/60; C23C2/06; C23C2/12; C23C2/28
Domestic Patent References:
| JP2013545890A | 2013-12-26 | |||
| JP2015151576A | 2015-08-24 | |||
| JP2013545890A | 2013-12-26 | |||
| JP2015151576A | 2015-08-24 |
Foreign References:
| WO2011111333A1 | 2011-09-15 | |||
| WO2012169640A1 | 2012-12-13 | |||
| WO2006006742A1 | 2006-01-19 | |||
| WO2012070482A1 | 2012-05-31 | |||
| WO2015182596A1 | 2015-12-03 | |||
| WO2015182591A1 | 2015-12-03 | |||
| WO2011111333A1 | 2011-09-15 | |||
| WO2012169640A1 | 2012-12-13 | |||
| WO2006006742A1 | 2006-01-19 | |||
| WO2012070482A1 | 2012-05-31 | |||
| WO2015182596A1 | 2015-12-03 | |||
| WO2015182591A1 | 2015-12-03 | |||
| US8628630B2 | 2014-01-14 |
Attorney, Agent or Firm:
Shigeru Inoue
Kazuhiro Mori
Kazuhiro Mori