About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
|
Symposium
|
Advances in Ferrous Metallurgy
|
Presentation Title |
Evolution of Heterogeneous Carbon Distribution during Austempering of TRIP Steel |
Author(s) |
Miku Watanabe, Goro Miyamoto, Satoshi Morooka, Tadashi Furuhara |
On-Site Speaker (Planned) |
Goro Miyamoto |
Abstract Scope |
In austempering of TRIP steel, austenite is stabilized by carbon enrichment during bainite transformation. Carbon diffusion in austenite is relatively slow, resulting in a heterogeneous carbon distribution in austenite even after the austempering process. This heterogeneity could affect the stability of retained austenite and significantly influence deformation-induced martensite transformation behavior. Therefore, the present study aims to investigate heterogeneous carbon distribution evolving in bainite transformation quantitatively. In-situ neutron diffraction (ND) measurement during bainite transformation and carbon mapping using FE-EPMA were conducted to characterize carbon distribution. ND experiment reveals that high-C austenite containing significant carbon heterogeneity evolves during bainite transformation. FE-EPMA measurement clarifies that such C heterogeneity is related to austenite grain size, and C content in austenite increases as the austenite grain size decreases. Thus, smaller austenite grains are stabilized by enhanced C enrichment and the size effect itself. |