Role of rolling temperature in the precipitation hardening characteristics of Ti-Mo microalloyed hot-rolled high strength steel

Rolling temperature was found to play a decisive role in the precipitation hardening of Ti-Mo microalloyed hot-rolled high strength steel, despite identical chemical composition and phase transformation condition. The different microstructural features of prior austenite grain structure and dislocation structures inside austenite and/or ferrite grain, and the change of austenite/ferrite phase transformation characteristic, depending on rolling temperature, significantly influenced the precipitation characteristics of interphase-precipitated nanometer-sized carbides and consequently led to a totally different precipitation hardening effect.