Title:
ボルト、及びボルト用鋼材
Document Type and Number:
Japanese Patent JP7464832
Kind Code:
B2
Abstract:
To provide a bolt which exhibits excellent delayed fracture resistance in a high strength level such that a risk of causing delayed fracture is extremely high and a tensile strength is 1,000 MPa or more, and a steel material for bolt used as the raw material of the same.SOLUTION: There are provided a bolt that has a predetermined composition satisfying expressions (1) and (2) and in which 10 or more M2C type carbides with a length of 5 nm or longer exist in unit volume of 0.001 μm3, and a tensile strength is 1,000 Mpa or more. Expression (1): 0.10<(2 V+0.5 W+0.4Cr)/Mo<0.50. Expression (2): (Mo/95.95+V/50.94+W/183.8-C/6.0>0. In Expressions (1) and (2), Mo, V, W, Cr and C are substituted by contents (mass%) of Mo, V, W, Cr and C contained in the bolt.SELECTED DRAWING: None
Inventors:
山▲崎▼ 真吾
Miyuri Umehara
Miyuri Umehara
Application Number:
JP2020085413A
Publication Date:
April 10, 2024
Filing Date:
May 14, 2020
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C22C38/00; C22C38/38; C22C38/60; F16B35/00
Domestic Patent References:
| JP2017066521A | ||||
| JP2006045670A | ||||
| JP10017985A | ||||
| JP2006131990A | ||||
| JP2002173739A | ||||
| JP8253843A |
Foreign References:
| WO2011111872A1 |
Attorney, Agent or Firm:
Patent Attorney Corporation Taiyo International Patent Office