Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy
Heat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during welding process. Preventing cracking during the repair welding of turbine components is important. In this study, the effects of heat input and pre-welding heat treatment on the microstructure, mechanica...
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MDPI AG
2020-10-01
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| Online Access: | https://www.mdpi.com/2075-4701/10/11/1453 |
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| author | Amirhossein Mashhuriazar Hamid Omidvar Zainuddin Sajuri C. Hakan Gur Amir Hossein Baghdadi |
| author_facet | Amirhossein Mashhuriazar Hamid Omidvar Zainuddin Sajuri C. Hakan Gur Amir Hossein Baghdadi |
| author_sort | Amirhossein Mashhuriazar |
| collection | DOAJ |
| description | Heat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during welding process. Preventing cracking during the repair welding of turbine components is important. In this study, the effects of heat input and pre-welding heat treatment on the microstructure, mechanical properties and crack formation in tungsten inert gas welding of IN-939 were investigated. The whole specimens were welded using Inconel 625 filler in an Ar atmosphere and characterised by metallographic examinations and hardness measurements. Results showed that the microstructures of IN-939 HAZs were highly susceptible to cracking during welding due to increasing of γ′ volume fraction. All of these cracks appeared in the HAZs and grew perpendicular to the melting zone along the grain boundaries. In this survey, the pre-welding heat treatment and heat input strongly affected the HAZ microstructure and hardness. However, the pre-welding heat treatment with 67% impact was more effective than heat input with 30% impact. Finally, hot tensile tests were carried out on the specimens of the base metal and the optimal specimens under similar operating conditions within 600 °C–800 °C. Welding process did not affect the yield strength of the superalloy but slightly decreased its ultimate strength and elongation by as much as 92% and 50%, respectively, of those of the base metal. |
| first_indexed | 2024-03-10T15:13:24Z |
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| id | doaj.art-e718814a9be2457493a12858c579f16f |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T15:13:24Z |
| publishDate | 2020-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-e718814a9be2457493a12858c579f16f2023-11-20T19:10:53ZengMDPI AGMetals2075-47012020-10-011011145310.3390/met10111453Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 SuperalloyAmirhossein Mashhuriazar0Hamid Omidvar1Zainuddin Sajuri2C. Hakan Gur3Amir Hossein Baghdadi4Department of Materials and Metallurgical Engineering, Amirkabir University of Technology, Tehran 1599637111, IranDepartment of Materials and Metallurgical Engineering, Amirkabir University of Technology, Tehran 1599637111, IranDepartment of Mechanical and Manufacturing Engineering, Faculty of Engineering and Built Environment, Universitiy Kebangsaan Malaysia, Bangi 43600, Selangor, MalaysiaDepartment of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06800, TurkeyDepartment of Mechanical and Manufacturing Engineering, Faculty of Engineering and Built Environment, Universitiy Kebangsaan Malaysia, Bangi 43600, Selangor, MalaysiaHeat-affected zones (HAZs) of Inconel 939 (IN-939) superalloy are susceptible to cracking during welding process. Preventing cracking during the repair welding of turbine components is important. In this study, the effects of heat input and pre-welding heat treatment on the microstructure, mechanical properties and crack formation in tungsten inert gas welding of IN-939 were investigated. The whole specimens were welded using Inconel 625 filler in an Ar atmosphere and characterised by metallographic examinations and hardness measurements. Results showed that the microstructures of IN-939 HAZs were highly susceptible to cracking during welding due to increasing of γ′ volume fraction. All of these cracks appeared in the HAZs and grew perpendicular to the melting zone along the grain boundaries. In this survey, the pre-welding heat treatment and heat input strongly affected the HAZ microstructure and hardness. However, the pre-welding heat treatment with 67% impact was more effective than heat input with 30% impact. Finally, hot tensile tests were carried out on the specimens of the base metal and the optimal specimens under similar operating conditions within 600 °C–800 °C. Welding process did not affect the yield strength of the superalloy but slightly decreased its ultimate strength and elongation by as much as 92% and 50%, respectively, of those of the base metal.https://www.mdpi.com/2075-4701/10/11/1453Inconel superalloyhigh-temperature alloyweldingheat treatmentprecipitationmechanical properties |
| spellingShingle | Amirhossein Mashhuriazar Hamid Omidvar Zainuddin Sajuri C. Hakan Gur Amir Hossein Baghdadi Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy Metals Inconel superalloy high-temperature alloy welding heat treatment precipitation mechanical properties |
| title | Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy |
| title_full | Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy |
| title_fullStr | Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy |
| title_full_unstemmed | Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy |
| title_short | Effects of Pre-Weld Heat Treatment and Heat Input on Metallurgical and Mechanical Behaviour in HAZ of Multi-Pass Welded IN-939 Superalloy |
| title_sort | effects of pre weld heat treatment and heat input on metallurgical and mechanical behaviour in haz of multi pass welded in 939 superalloy |
| topic | Inconel superalloy high-temperature alloy welding heat treatment precipitation mechanical properties |
| url | https://www.mdpi.com/2075-4701/10/11/1453 |
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