Title:
SOFT HOT ROLLED STEEL SHEET EXCELLENT IN WORKABILITY AND FATIGUE RESISTANCE IN WELDED JOINT
Document Type and Number:
Japanese Patent JP3246278
Kind Code:
B2
Abstract:
PURPOSE: To produce a steel sheet good in aging properties, having a stable balance of strength and ductility and excellent in press formability and fatigue resistance in a welded joint by compositely adding Ti and B to a low carbon aluminum killed steel and optimizing each amt. of the elements to be contained to uniformize the ferritic structure in a hot coil.
CONSTITUTION: The compsn. of a steel sheet is composed of the one contg., by weight, 0.015 to 0.050% C, 0.05 to 0.5% Mn, <0.01% S, 0.005 to 0.10% Al, ≤0.004% N and 0.0002 to 0.0015% B, furthermore contg. Ti in a range shown by the inequality, and the balance Fe with inevitable impurities. As for the steel having the above compsn., the change in a balance of strength and ductility accompanying the change in temp. is smaller than that in a general carbon hot rolled steel sheet, mechanical properties stable in the operation can be obtd., and the ductility to the strength can also be improved. Furthermore, the aging index after aging at 100°C for 1hr under 8% prestrain can be regulated to ≥3kg/mm2.
Inventors:
Toshiaki Urabe
Katsumi Nakajima
Masaki Ohmura
Katsumi Nakajima
Masaki Ohmura
Application Number:
JP16653595A
Publication Date:
January 15, 2002
Filing Date:
June 30, 1995
Export Citation:
Assignee:
Nippon Steel Tube Co., Ltd.
International Classes:
C21D8/02; C22C38/00; C22C38/14; (IPC1-7): C22C38/00; C22C38/14
Domestic Patent References:
| JP63216925A | ||||
| JP63143224A | ||||
| JP6150125B2 | ||||
| JP5414563B2 |
Attorney, Agent or Firm:
Takehiko Suzue