Optimization of Weld Conditions and Alloy Composition for Welding of Single-Crystal Nickel-Based Superalloys

Conference · Mon Jan 01 04:00:00 EST 2007

OSTI ID:931252

Vitek, John Michael ^[1]; David, Stan A ^[1]; Babu, Sudarsanam S ^[1]

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1. ORNL

Calculations were carried out to identify optimum welding conditions and weld alloy compositions to avoid stray grain formation during welding of single-crystal nickel-based superalloys. The calculations were performed using a combination of three models: a thermal model to describe the weld pool shape and the local thermal gradient and solidification front velocity; a geometric model to identify the local active dendrite growth variant, and a nucleation and growth model to describe the extent of stray grain formation ahead of the advancing solidification front. Optimum welding conditions (low weld power, high weld speed) were identified from the model calculations. Additional calculations were made to determine potential alloy modifications that reduce the solidification temperature range while maintaining high gamma prime content. The combination of optimum weld conditions and alloy compositions should allow for weld repair of single-crystal nickel-based superalloys without sacrificing properties or performance.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC); FE USDOE - Office of Fossil Energy (FE); ORNL work for others
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 931252
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
DENDRITES
HEAT RESISTING ALLOYS
MODIFICATIONS
NUCLEATION
OPTIMIZATION
PERFORMANCE
REPAIR
SHAPE
SOLIDIFICATION
TEMPERATURE GRADIENTS
WELDING