Title:
MO-BASED ULTRAHIGH TENSILE STRENGTH RESISTANCE WELDED STEEL TUBE EXCELLENT IN DUCTILITY
Document Type and Number:
Japanese Patent JP3117529
Kind Code:
B2
Abstract:
PURPOSE: To provide an Mo-based ultrahigh tensile strength resistance welded steel tube used for structural members for automobile, etc., and excellent in tensile strength and ductility.
CONSTITUTION: In a resistance welded steel tube having a composition consisting of, by weight, 0.15-0.30% C, 0.05-0.50% Si, 2.0-3.0% Mn, 0.005-0.020% P, 0.0005-0.0060% S, 0.01-0.08% Al, 0.001-0.003% B, 0.002-0.0050% N, 0.3-1.5% Mo, 0.01-0.20% Ti and/or 0.01-0.20% Nb, and the balance Fe with inevitable elements, normalizing is done as heat treatment and a microstructure composed essentially of bainite is formed. This method is economical because it can dispense with hardening after resistance welded steel tube making for forming an ultrahigh tensile strength resistance welded steel tube, and even square steel tubes and steel tubes of special form can be easily produced.
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Inventors:
Yukio Kimiya
Daigo Sumimoto
Daigo Sumimoto
Application Number:
JP4941992A
Publication Date:
December 18, 2000
Filing Date:
March 06, 1992
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C21D8/10; C21D9/08; C22C38/00; C22C38/22; (IPC1-7): C22C38/00; C21D8/10; C21D9/08; C22C38/22
Domestic Patent References:
| JP552749A | ||||
| JP4972119A | ||||
| JP331442A | ||||
| JP3140441A | ||||
| JP62263924A | ||||
| JP5943821A |
Attorney, Agent or Firm:
Masayuki Kishida (2 outside)