Tailoring the Mechanical Properties of Copper-Added Transformation-Induced Plasticity-Aided Multiphase Steel by Thermomechanical Processing

Herein, the microstructure and mechanical properties of a low-alloy Cu-bearing transformation-induced plasticity (TRIP) steel and their dependence on the processing history are investigated. The distributions of the retained austenite and bainite are found to be dependent on the initial cold-rolled microstructure, which can be tailored by the preceding hot-rolling route (unidirectional/cross rolling) and the subsequent cooling rate (furnace/air cooling). Mechanical properties and TRIP effect strongly depend on the initial microstructure, where the air-cooled sheet shows remarkable mechanical properties; while the cross-rolled sheet shows isotropic properties. The addition of copper results in an increase in the amount of the retained austenite, enhancement of strength-ductility balance, and improvement of the hardening behavior of TRIP-assisted high-performance steel. Mechanical properties, transformation-induced plasticity (TRIP) effect, and the distribution of microstructural features of low-alloy Cu-bearing TRIP steel strongly depend on the initial microstructure, which can be tailored by the preceding hot-rolling route (unidirectional/cross rolling) and the subsequent cooling rate (furnace/air cooling). The addition of copper results in an increase in the amount of the retained austenite and an enhancement of strength-ductility synergy.image (c) 2023 WILEY-VCH GmbH