The effects of Nb on mechanical twinning and tensile deformation behavior were investigated in hot-rolled Fe18Mn0.6C1.5Al twinning-induced plasticity (TWIP) steels without and with 0.1Nb. In comparison to the Nb-free TWIP steel with fully-recrystallized and equiaxed grains, the Nb-added TWIP steel showed non-recrystallized and elongated grains with well-dispersed NbC particles and a high density of dislocations. The increased yield and tensile strengths in the Nb-added TWIP steel were mainly caused by the hardening of dislocations in non-recrystallized grains rather than the precipitation hardening of NbC particles or the solid solution hardening of Nb atoms. Meanwhile, the uniform elongation and strain hardening rate of the Nb-added TWIP steel were decreased due to inactive mechanical twinning, which is probably because the dislocations interfere with the movement and dissociation of dislocations necessary for mechanical twinning.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering