| Thermo-Mechanical Processing-Induced Microstructure Refinement of Co-28Cr-6Mo-0.33C Alloy and Its Impact on Wear Behavior |
| کد مقاله : 1107-ICME2025 |
| نویسندگان |
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فاطمه زهرا حسنی جبلی1، آیدین درودی *2 1شرکت طراحی مهندسی و تامین قطعات ایران خودرو (ساپکو) 2دانشگاه صنعتی امیرکبیر ساپکو |
| چکیده مقاله |
| Grain refinement in Co-28Cr-6Mo-0.33C alloy was achieved through minimal plastic deformation and a two-step heat treatment. The solution-treated specimens were furnace-cooled, resulting in a pearlitic structure at grain boundaries. These were then compressed and aged at 850°C, leading to the decomposition of the austenite phase into a lamellar eutectoid structure (α+M23C6). Reverse treatment at temperatures stabilizing austenite facilitated nucleation of a fine-grained austenitic structure with an average grain size of 48.23 μm, about one-tenth of the original size. The hot compression behavior was examined between 1100-1200°C and strain rates of 0.001-1 s-1. The activation energy was calculated as 744.6 kJ/mol. Microstructural analysis showed competition between dynamic recrystallization (DRX) and precipitation, especially at low strain rates (0.001 s-1). Precipitates at grain boundaries hindered DRX, while prolonged coarsening of precipitates promoted DRX. This competition caused serrated grain boundaries and oscillations in the flow curves. Wear behavior, assessed by pin-on-disk tests, indicated that carbide shape, distribution, and size significantly affected wear resistance. Large and lamellar carbides resulted in lower wear resistance compared to fine globular carbides in solution-treated and quenched specimens. ε-Martensite formation during sliding reduced wear rate due to fewer slip systems in the hexagonal structure. |
| کلیدواژه ها |
| Co-Cr-Mo-C alloys, Material characterization, Microstructural refinement, Precipitate formation, Microstructural improvement, Tribological behavior. |
| وضعیت: پذیرفته شده برای ارائه شفاهی |
