Effect of cooling rate and chemistry on mechanical properties of Ti-V HSLA plate steels

High strength low alloy (HSLA) steels are known for their superior mechanical properties, which are achieved through alloying elements and controlled hot rolling. In this work, the effect of cooling rate and alloying elements on the final microstructure and mechanical properties of Ti-V HSLA microalloyed steels were investigated. The Gleeble 1500TM TM was used to simulate the plate rolling process. The samples were cooled to room temperature using two different cooling rates to simulate the 16 and 30mm thick plate cooling patterns in the alloy. Increasing the cooling rate and amount of carbon equivalent promoted acicular ferrite and bainite transformation, and also led to the decrease in grain size. Consequently, both the yield strength and UTS increased with increasing cooling rate with a slight drop in uniform elongations.