Novel Dissimilar Joints Between Alloy 800H and 2.25%Cr and 1%Mo Steel

Technical Report · Sun Dec 31 00:00:00 EST 2017

DOI:https://doi.org/10.2172/1428204· OSTI ID:1428204

DebRoy, Tarasankar ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

Dissimilar metal joints between ferritic steels and nickel base alloys are currently fabricated using conventional arc welding processes with selected filler metal combinations. The dissimilar metal joints contain abrupt changes in composition over a relatively small distance. Many years of service at elevated temperatures has shown that these welds are susceptible to creep and creep fatigue failures. The primary mechanism for these creep failures involves carbon diffusion from the ferritic steel to the nickel base alloy. As a result, a carbon depleted zone is created that contains very few stable carbides. This work used additive manufacturing (AM) technologies as a highly controllable means for reducing carbon migration through theoretically designed, compositionally graded transition joints guided by appropriate thermodynamic, kinetic and heat transfer and fluid flow modeling. The contents of the report include the objectives and tasks set forth by the PI and collaborators, major technical accomplishments throughout the research and additional details in the form of technical publications resulting from the NEUP grant and reports from the collaborating university and national laboratory.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States); The Ohio State Univ., Columbus, OH (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE). Nuclear Energy University Program (NEUP)
• DOE Contract Number: NE0008280
• OSTI ID: 1428204
• Report Number(s): 14-6803; 14-6803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING