Title:
MANUFACTURE OF DUPLEX STAINLESS STEEL WELDED TUBE
Document Type and Number:
Japanese Patent JP3146890
Kind Code:
B2
Abstract:
PURPOSE: To provide the corrosion resistance of the same degree as that of the base metal to the weld zone by achieving the postheating treatment of a weld seam part after forming the duplex stainless steel strip in an open-tube shape, and achieving the laser beam welding of both edge parts under the prescribed condition.
CONSTITUTION: The steel strip stuck made of duplex stainless steel is continuously formed in an open-tube shape, and each edge of the steel strip is butted to each other by a squeeze roll. This butted part is irradiated with the laser beam to achieve the tube-making welding under the condition expressed by the inequalities of P≥0.4Vt/exp(aT)≥20, where P is the laser beam output (KW), V is the welding speed (m/min), (t) is the thickness (mm) of the stock steel strip, T is the preheating temperature (°C) at each edge part of the steel strip, and (a) is the constant (=0.0006), and T=0°C in the case without preheating. After the laser beam welding, the weld seam part is postheated at 1000-1100°C, and the ferritic ratio of the structure of the weld metal is adjusted so that the ferrite ratio as large as that base metal may be approximately 50%.
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Inventors:
Tomohiko Ohmura
Takahiro Kushida
Takahiro Kushida
Application Number:
JP29967594A
Publication Date:
March 19, 2001
Filing Date:
December 02, 1994
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B21C37/08; B23K26/00; B23K26/21; B23K26/32; C21D9/08; C21D9/50; C22C38/00; (IPC1-7): B23K26/00; B21C37/08; C22C38/00
Domestic Patent References:
| JP6170569A | ||||
| JP6128691A |
Attorney, Agent or Firm:
Morio Mori (1 outside)