Microstructure Characterization and Creep Behavior on the Casting CMM88Y Super Alloy turbine Blade

Document Type : Original Research Article

Authors

1 ‎Ph.D. Student, in Materials Science and Metallurgical Engineering, Amirkabir University of Technology, ‎Iran,

2 Associate Professor, Department of Materials and Metallurgical Engineering

3 Engineer, Iranian Gas Transmission Company, I.G.T.C.‎

10.22034/frj.2023.391115.1177

Abstract

In this study, the mechanical properties of gas turbine blades are investigated by investment casting method. These Nickel-based alloys blades, with standard name, CM88Y, are made in Ukraine. Currently, these blades are used in Zorya brand gas turbines in most power plants in Iran. Therefore the technical information about this alloy are very limited. In this investigation, the CM88Y Nickel base alloy as a Ni-Co heat resistant super-alloy was assessed by a lot of destructive tests. Mechanical and creep properties as well as the phase microstructure for a turbine blade were measured after 6000 and 18,000 hours. The creep results by adding Larson-Miller parameter, revealed that the 18,000-hour blade with the hot-spot zone defect has a creep life less than 3,800 hours due to the TBC erosion and hot-spot defect. Also, the gamma prime phase has changed from a cubic morphology to a spherical shape associated to the coarsening phenomenon.

Keywords

Main Subjects


[1] Kvasnytska I.H., Improving the performance of working blades of modern industrial gas turbine engines, Metals and Casting of Ukrain, 2015, 8(267) 29-31.
[2] Kvasnytska I.H. , Increase of operational characteristics of Nickel-based superalloys and development of a complex alloying technology for producing GTE blades, PhD Thesis, National Academy of Sciences of Ukraine, Kiev, 2018.
[3] Zorya M., Heat resistant alloy castings made by vacuum poring, Technical Report, Nikolaev, Ukraine, 2008.
[4] Y.G. Kvasnitskaya, Performance improvement rotor blades of modern industrial turbines gas turbine engines, Physico-Technological Institute of Metals and Alloys of the National Academy of Sciences of Ukraine, Kyiv, Metal and Casting of Ukraine, 2015, 267(8) 29
[5] نجمی م.، میرباقری س.م.ح.، صالحی ع ، تحقیقات برای ریشه‌یابی خرابی (RCA) علل خرابی‌های پره‌های توربین‌های ZORYA UGT25000-DU80  در سایت سراجه‌ی، گزارش معاونت پژوهشی دانشگاه صنعتی امیرکبیر، شماره:20310/د، شهریور 1401.
[6] گرجی م.، بررسی اثر تغییر سرعت سرمایش از دمای عملیات انحلالی بر ریزساختار، خواص کشش گرم و رفتار خزشی سوپرآلیاژ پایه نیکل CM88Y، پایان‌نامه کارشناسی ارشد، دانشگاه صنعتی شریف، 1394.
[7] Kablov E.N., Toloraiya V.N., Orekhov N.G., Single-crystal nickel rhenium-containing alloys for turbine blades, Metal Science and Heat Treatment of Metals, 2002, 7, 2-5.
[8] شرکت علوم و فناوری نوین رهیافت، گزارش تعیین عمر خزشی پره‌های HP توربین گازی GE، شرکت پتروشیمی پارس عسلویه، 1395.
[9] Jiarong L.I., Dingzhong T., Riling L., Shizhong L., Zhongtang W., Effects of Rhenium on creep rupture life of a single crystal superalloys, Journal of Material Science and Technology, 1999, 15(01) 53-57.
[10] Electro-Chemical Etching User Guide and Accessories Catalogue, No: ENG099, Issue 1.5 Mar 2017.