Title:
DOUBLE PIPE AND WELDED STRUCTURE UTILIZING SAME
Document Type and Number:
WIPO Patent Application WO/2013/118585
Kind Code:
A1
Abstract:
This double pipe for a welded structure exhibits excellent weld crack resistance, wherein: said double pipe is composed of an inner pipe that is made of a ferrite heat-resistant steel having a chemical composition comprising specific amounts of C, Si, Mn, P, S, Ni+Cu, Cr, Mo+W, V, Nb, Ti, B, Al, N, and O with the balance comprising Fe and impurities and an outer pipe that is made of an austenite heat-resistant steel having a chemical composition comprising specific amounts of C, Si, Mn, P, S, Ni, Cr, Al, N, and O with the balance comprising Fe and impurities; fillet-welded sections that satisfy the expression [outer pipe thickness ≥ depth of melt caused by fillet-welding + 0.3mm] are formed on the outer surface of the double pipe; and the thicknesses (mm) of the outer pipe and the inner pipe satisfy the expression [outer pipe thickness / (outer pipe thickness + inner pipe thickness) ≤ 0.4]. When this double pipe is used, a welded structure for constructing high-temperature components of various kinds can be manufactured by fillet-welding boards, metal fittings, and the like to the outer surface of the pipe by means of an ordinary submerged arc welding without requiring treatments such as preheating, postheating, and steel cleaning. The inner pipe may contain one or more kinds selected from Ca, Mg, and REM, and the outer pipe may contain one or more kinds selected from Mo, W, Cu, Co, Nb, Ti, V, B, Ca, Mg, and REM.
Inventors:
HIRATA HIROYUKI (JP)
YOSHIZAWA MITSURU (JP)
OGAWA HIDENORI (JP)
YOSHIZAWA MITSURU (JP)
OGAWA HIDENORI (JP)
Application Number:
PCT/JP2013/051413
Publication Date:
August 15, 2013
Filing Date:
January 24, 2013
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
B23K9/00; C22C38/00; B23K9/02; B23K9/028; C22C38/54; C22C38/58; F22B37/04; B23K103/04
Foreign References:
| JPS61562A | 1986-01-06 | |||
| JPS59176501A | 1984-10-05 | |||
| JPS57120002A | 1982-07-26 | |||
| JP2007217783A | 2007-08-30 | |||
| JPH09217146A | 1997-08-19 | |||
| JP2004003000A | 2004-01-08 | |||
| JPH06322488A | 1994-11-22 | |||
| JPS60100640A | 1985-06-04 | |||
| JPS6455352A | 1989-03-02 | |||
| JPH02200756A | 1990-08-09 | |||
| JPH07216511A | 1995-08-15 | |||
| JPH07331390A | 1995-12-19 | |||
| JPH08127848A | 1996-05-21 | |||
| JPH08218140A | 1996-08-27 | |||
| JPH06106237A | 1994-04-19 | |||
| JPS57120002A | 1982-07-26 | |||
| JPS6417806A | 1989-01-20 | |||
| JPH05279801A | 1993-10-26 |
Other References:
See also references of EP 2813594A4
Attorney, Agent or Firm:
SUGIOKA, Kanji et al. (JP)
Sugioka Miki 2 (JP)
Sugioka Miki 2 (JP)
Download PDF:
Claims: