Coupled model for carbon partitioning, diffusion, Cottrell atmosphere formation and cementite precipitation in martensite during quenching

• DOI: 10.1016/j.commatsci.2022.111413
• Publication Date: 2022-04-11T17:18:31Z
• Authors: Aarne Pohjonen; Shashank Ramesh Babu; Ville-Valtteri Vi...
• Keywords: Lath; Supersaturation; Carbon fibers

High-strength low alloy martensitic steels are produced by quenching methods to achieve a microstructure. The carbon supersaturation of the structure serves as driver for autotempering, which has advantageous effects on physical properties steel and may take place even at very high cooling rates. So far, precipitation kinetics during have been modelled with assuming no loss due diffusion from martensite into inter-lath austenite, partitioning modeled without considering precipitation, although previous thermodynamic calculations show both occur similar rates, thus should be concurrently. In addition, segregation dislocations needs taken in account. aim this work was develop such coupled model that can predict these phenomena concurrently context formation rapid quenching. By comparing predictions experimental data two grades austenized subsequently quenched rates (120 °C/s 1000 °C/s), it found calculated maximum radius precipitates well their number distributions were good agreement observations. further work, is possible extend account also more complex heat cycles.