Austenite-Ferrite Transformation in Hot Rolled Mn-Cr-Mo Dual Phase Steels

Abstract

Interrupted cooling in the run-out table after hot rolling is a processing strategy to produce dual phase ferrite-martensite steel strips. The effects of interrupted cooling temperature and time after austenitizing at 1150 °C are investigated. This is done to establish the conditions for austenite to transform into ferrite-martensite microstructures in a Mn-Cr-Mo strip produced from a CSP (Continuous Strip Processing)-type thin slab. The results show that dual phase microstructures can only be obtained when interrupted cooling is performed at 725<T<800 °C. The amount of martensite and the strength level that can be developed increase as the interrupted cooling temperature increases. Formation of pearlite during the isothermal holding causes a rapid decrease in the level of strength that can be developed in this type of structural material.

Strain-Hardening Prediction of DP600 Steel Considering the Heterogeneous Deformation Between Ferrite and Martensite

“…First, the production processes are controlled to obtain better microstructures. To obtain ferrite and martensite, one method is hot rolling by controlling the final rolling temperature and cooling rate [3]. The other method is cold rolling to control the microstructure distribution with inter-critical annealing [4].…”