Underwater wet flux-cored arc welding development of stainless steel and nickel-based materials

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:234156

Findlan, S J; Frederick, G J ^[1]

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1. EPRI Repair and Replacement Applications Center, Charlotte, NC (United States)

The inaccessibility and high radiation fields of components in the lower two thirds of a reactor pressure vessel (RPV) has generated the need for an automated underwater wet welding process to address repair applications. Mechanical methods presently employed for this type of repair application produce crevices, which promote concerns of intergranular stress corrosion cracking (IGSCC), crevice corrosion and pitting. To address these concerns, the EPRI Repair and Replacement Applications Center (RRAC) has developed underwater wet flux-cored arc welding (FCAW) technology for the welding of stainless steel and nickel based materials. The benefits of underwater wet welding include: (1) provides a permanent repair; (2) offers crevice-five conditions; (3) reduces future inspection requirements (4) eliminates the potential for ``loose parts`` (5) can be performed in a timely approach. Underwater wet shielded metal arc welding (SMAW) has been successfully used to repair components in radiation areas of the upper section of the RPV, although this process is a manual operation and is impractical for remote applications. The developmental work at the EPRI RRAC is directed towards remote repair applications of nickel-based and stainless steel components, which are inaccessible with normal manual repair techniques, e.g., access hole covers. The flux-cored arc welding process (FCAW) was considered a viable option for underwater development, due to the ease of automation, out of position welding proficiency and self-shielding capabilities.

• OSTI ID: 234156
• Report Number(s): CONF-9411168--; ISBN 0-87171-444-2
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
ARC WELDING
CRACK PROPAGATION
DATA
MECHANICAL PROPERTIES
NICKEL BASE ALLOYS
PITTING CORROSION
REACTOR COMPONENTS
REMOTE HANDLING
REPAIR
STAINLESS STEELS
WELDED JOINTS