Title:
疲労特性と成形性に優れた鋼板およびその製造方法
Document Type and Number:
Japanese Patent JP6668662
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To enhance lower limit stress intensity factor range (ΔKth) even in a steel sheet short in crack propagation life in fatigue life for enhancing fatigue property and moldability even with the steel sheet having thin sheet thickness.SOLUTION: There is provided a steel sheet having effective carbon amount (Ceff) calculated by using Ti content (Tief) capable of being deposited as TiC of 0.002% to 0.050% and containing predetermined components, wherein it is found to be suitable that it contains crystal particles with average of orientation difference in the crystal particle of 0 to 0.5°, when the crystal particle is defined as an area surrounded by a particle boundary with orientation difference with neighboring crystal of 15° or more, of 90% or more by area percentage, sum of area percentage of a hard phase is 2% or less and further solid solution carbon amount in the crystal particle with average of orientation difference of 0 to 0.5° of 20 to 200 ppm. Tief=[Ti]-48/14×[N]-48/32×[S] (Formula a). Ceff=[C]-12/48×Tief (Formula b).SELECTED DRAWING: None
Inventors:
Hiroshi Suto
Hirosaku Ushioda
Sakurada Eisaku
Nobuyuki Yoshimura
Hirosaku Ushioda
Sakurada Eisaku
Nobuyuki Yoshimura
Application Number:
JP2015194582A
Publication Date:
March 18, 2020
Filing Date:
September 30, 2015
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C22C38/00; C21D9/46; C22C38/14; C22C38/58
Domestic Patent References:
| JP2012012658A |
Foreign References:
| WO2015118863A1 | ||||
| WO2010137317A1 |
Attorney, Agent or Firm:
Atsushi Aoki
Takashi Ishida
Tetsuji Koga
Hiroshi Kamematsu
Fukuchi Ritsuo
Nakamura Asayuki
Takashi Ishida
Tetsuji Koga
Hiroshi Kamematsu
Fukuchi Ritsuo
Nakamura Asayuki