Supervisor:
Southwest Ordnance Industry Bureau
Organizer:
Chongqing Ordnance Industry Society
Chongqing University of Technology
Chongqing University of Technology
Numerical simulation and experimental study on quenching of high carbon chromium bearing outer ring
| DOI: | 10.11809/bqzbgcxb2023.10.012 |
| Keywords: | GCr15; heat treatment; numerical simulation; carbides; M 23 C6 |
| Abstract: | Taking GCr15 bearing rings as the research object, numerical simulation and experimental research methods are used. In terms of numerical simulation, COSMAP numerical simulation software is used to simulate the quenching of the outer ring of GCr15 bearing. The quenching process is selected as follows: heating at 845 ℃+holding for 25 minutes+oil quenching, with a heating time of 15 minutes. The simulation results show that the cooling speed of the outer ring center of the bearing is different from that of the outer ring. The external cooling speed is faster than the center speed, and the cooling speed of the outer and inner surfaces is basically the same; During quenching, as long as the structure is martensite and residual austenite, martensite is distributed from inside to outside due to the fast external cooling rate; At the beginning of quenching, the external radial displacement decreases faster than the center, and under the combined action of structural stress and thermal stress, a reverse increase process occurs, which then stabilizes. In terms of experimental research. The surface of the bearing ring is treated using magnetic grinding technology to remove most impurities and oxides, making it easy to observe the test piece. Electron backscatter diffraction analysis (EBSD) is used to determine the type of carbide in the outer ring of the bearing as M 23 C6 type carbides.Field emission scanning electron microscopy (SEM) is used to observe the pre treated outer ring, and the observation results showed that the mechanism of morphological changes in M 23 C6 type carbides can be summarized as follows: multiple isolated cores come into contact with their adjacent cores to form rod shaped carbides; a single core continues to grow or multiple cores come into contact with each other to form blocky carbides; rod shaped carbides come into contact with each other or with block shaped carbides, resulting in the formation of irregular sheet shaped carbides, namely eutectic carbides. |
| Issue: | Vol. 44 No. 10 (2023) |
| Published: | 2023-10-28 |
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