|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced High-strength Steels
||Important Factors to Design High-strength Ferritic Steel with Nano-sized Interphase Precipitation of Alloy Carbide
||Tadashi Furuhara, Yongjie Zhang, Goro Miyamoto
|On-Site Speaker (Planned)
In steels containing strong carbide-forming elements, alloy carbides are precipitated by periodic nucleation at migrating ferrite/ interface during ferrite transformation, which is called interphase precipitation. Since larger precipitation strengthening is obtained by increasing the number density of precipitates, the present study aims to clarify the factors influencing carbide dispersion in low carbon steels. Interphase precipitation mainly occurs at incoherent ferrite/austenite interface with large deviation from the Kurdjumov-Sachs orientation relationship, partially due to segregation of alloying elements. Larger number density of precipitates is obtained at higher alloying contents and lower transformation temperature where grain boundary ferrite forms in good correlation with supersaturation at the interface. Also the volume fraction of carbide does not reach to the full equilibrium, limited by the Gibbs-Thomson effect. Since ferrite growth rate has only a minor effect, it is concluded that carbide dispersion can be dominantly controlled by the driving force of precipitation.
||Planned: Supplemental Proceedings volume