Title:
TUBE STOCK FOR HIGH STRENGTH THICK-WALLED WELDED BEND STEEL TUBE HAVING SUPERIOR TOUGHNESS AT WELDED PORTION AND METHOD FOR MANUFACTURING THE SAME
Document Type and Number:
Japanese Patent JP2011067871
Kind Code:
A
Abstract:
To provide a tube stock for high strength thick-walled welded bend tube having superior toughness at low temperature for an entire portion of welded metal which is as-welded, or as induction-hardened, or subjected to heat treatment, namely, induction hardening and tempering or tempering.
In the contents of the welded metal, amounts of Ti, V, Al, O, N, B and Ni, in particular, satisfy the following component ranges and equations (1) and (2). Ti: 30 to 400 ppm, V: 20 to 500 ppm, Al: 20 to 500 ppm, O:500 ppm or less, N: 80 ppm or less, B: 3 to 60 ppm and Ni: 3.0 mass% or less, [N]-0.087[Ti]-0.03[V]-9≤0...(1) and 0.17≤[B]/G≤2.5...(2) wherein, G=0.15[O]-0.113[Al]-0.0345[Ti]+1.
Inventors:
HAYAKAWA NAOYA
IHARA KOICHI
YASUDA KOICHI
IHARA KOICHI
YASUDA KOICHI
Application Number:
JP2010241478A
Publication Date:
April 07, 2011
Filing Date:
October 27, 2010
Export Citation:
Assignee:
JFE STEEL CORP
International Classes:
B23K35/30; B23K9/025; B23K9/18; B23K9/23; B23K35/362; C22C38/00; C22C38/58; B23K101/06; C21D9/08; C21D9/50
Domestic Patent References:
| JPH09296253A | 1997-11-18 | |||
| JPH10306347A | 1998-11-17 | |||
| JPH11267844A | 1999-10-05 | |||
| JPS62107023A | 1987-05-18 | |||
| JPS6210212A | 1987-01-19 | |||
| JPS59232225A | 1984-12-27 | |||
| JPH11172374A | 1999-06-29 |
Attorney, Agent or Firm:
Kenji Sugimura
Kiyoshi Kuruma
Keisuke Kawahara
Kiyoshi Kuruma
Keisuke Kawahara