EXPERIMENTAL INVESTIGATION of DOUBLE AGING HEAT TREATMENT of INCONEL 718 MONOBLOCK GAS TURBINE DISC IN A SALT BATH
Öz
The heat treatment of Inconel 718 (In718) monoblock gas turbine discs are mainly done by vacuum furnaces. Despite the vacuum furnaces allow to make a clean and reliable heat treatment, its operation costs affects the final product’s cost. In this work, as an alternative to the vacuum furnaces, the double aging heat treatment of In718 disc in a salt bath was investigated. The appropriate temperature for high and low temperature salt bath was identified in order to achieve necessary cooling rates of 125°C/min and 120°C/min for a 400 kg workpiece. It is shown that the heat treatment could be done when the high and low temperature salt baths temperatures are equal to 300°C. It is also found that the heat transfer coefficient for simulation could be taken as 650 W/m2.K regardless to the salt bath temperature.
Anahtar Kelimeler
Salt Bath, Aging, Heat Transfer Coefficient, Superalloy, Simulation
Teşekkür
The authors would like to thank to the HEF-Durferrit Turkey branch general manager Şarkay ŞAŞİ for his support and supplying the GS-230 salt properties.
Kaynakça
- Donachie MJ, Donachie SJ. Superalloys a technical guide, ASM International, Ohio, USA 2002.
- Totten GE, Dossett J. ASM handbook volume 4A:steel heat treating fundamentals and processes, ASM International, Ohio, USA, 2014.
- El-Bagoury N. Ni based superalloy: casting technology, metallurgy, development, properties and applications. International Journal of Engineering Sciences and Research Technology 2016; 5(2)108-152.
- Candioto KCG, Caliari FR, Reis DAP, Couto AA, Nunes CA. Characterization of the superalloy Inconel 718 after double aging heat treatment. In: Öchsner A., Altenbach H. (eds) Mechanical and materials engineering of modern structure and component design. advanced structured materials. Springer 2015.
- Donachie M, Donachie S Jr. Superalloys: a technical guide, 2nd edn. ASM International, USA 2002.
- American Society for metals ASM handbook volume 4: heat treatment. ASM International, USA 1991.
- Davis JR. Heat-resistant materials, ASM International, New York, USA 1997.
- Liscic B, Tensi HM, Canale LCF, Totten GE. Quenching theory and technology, CRC Press, Boca Raton, USA 2010.