Effect of Titanium on Hot Deformation Behaviors of Boron Microalloyed Steel

Abstract

The hot deformation behaviors of titanium-free and titanium-treated boron microalloyed steel were investigated at the temperatures from 850°C to 1 100°C and strain rates from 0.1 s − 1 to 10 s − 1 on Gleeble-2000 thermo-mechanical simulator. It was found that the flow stress of the titanium-treated steel is lower than that of titanium-free at lower strain rates, indicating that titanium addition generates a softening effect. The flow stress constitutive equations of hot deformation were developed for the experimental steels, the activation energy of titanium-treated steel (299.7 kJ·mol − 1 ) is higher than that of the titanium-free steel (286.9 kJ·mol − 1 ). Additionally, it is interesting to note that the peak and critical strain are lowered by titanium addition, indicating that titanium has the ability to promote the onset of dynamic recrystallization. However, the dynamic recrystallization kinetics of titanium-free steel is faster than that of titanium-treated steel.

A new dynamic recrystallization kinetics model for a Nb containing Ni-Fe-Cr-base superalloy considering influences of initial δ phase

“…Then, the nucleation and growth of DRX grain occur. So, a high DRX volume fraction is acquired at the lower strain rate or higher deformation temperature [58,59].…”

Influence of Alloying Elements on the Dynamic Recrystallization of 4 wt.–% Medium Manganese Steels

“…As the titanium concentration is to low to protect all boron from nitrogen, the amount of solute boron is not sufficient in lab-1. These interactions were also observed in microalloyed steels with conventional manganese concentrations [ 13 ]. Lab-3 showed higher equivalent stresses in the temperature range from 800 to 1100 in comparison to lab-5.…”

“…Besides the equivalent stress, the ability of the material to exhibit dynamic recrystallization is important as well as the recrystallization leads to dislocation annihilation and new grain formation [ 8 ]. Several studies have been published in the past, investigating the influence of alloying elements like molybdenum [ 9 , 10 ], aluminium [ 11 ], titanium [ 9 , 12 , 13 ] and niobium [ 9 , 12 , 14 , 15 ] on the microstructural features during hot deformation, especially dynamic recrystallization (DRX), but none of these studies investigated materials with higher manganese concentrations being of interest for the present applications. The deformation behaviour of MMnS is only characterized for sheet products [ 16 , 17 , 18 ] using tensile test.…”

Influence of Vanadium Content on Hot Deformation Behavior of Low-Carbon Boron Microalloyed Steel

“…The flow stress of each experimental steel increases considerably with decreasing the deformation temperature and increasing the strain rate. Generally, during the high temperature deformation of austenite, the strain hardening, dynamic recovery (DRV) or dynamic recrystallization (DRX) occur depending on the parameters of deformation process such as deformation temperature and strain rate [3,21]. All the flow curves of the experimental steels exhibit DRV or DRX behavior in given temperature and strain rate.…”

“…In the research works on the high-strength high-toughness steels, the addition of boron to microalloyed steel with Ti, V and Nb has been widely used to improve the mechanical properties of steel [1,2]. Boron is regarded as one of the most effective elements to realize the transformation strengthening in the steel [3]. The adding of boron to the low-carbon low-alloy steels increases remarkably the hardenability of steel [4], and it allows the expensive elements such as Cr, Ni and Mo to replace or reduce [5].…”