In situ TEM investigation on cryogenic deformation mechanism of twinning-induced plasticity steel
Using in situ straining tests in transmission electron microscopy,we investigate the deformation behavior of twinning-induced plasticity deformation steel during uniform plastic deformation stages at-50℃、-120 ℃ and-180 ℃,and analyze the dependence of temperature on the dislocation slip and twinning behaviors.It is found that at-50 ℃,in addition to general slip systems in TWIP steel,extra slip system is activated;and with the decrease of temperature,the dislocation activities in TWIP steel behave similarly to that at room temperature,especially the cross slip of dislocation requiring thermal activation could still occur at-180 ℃.The result indicates that the maintenance of ability of twinning and dislocation slip at cryogenic temperature renders the TWIP steel deforming by coordination of multiple deformation mechanisms,including deformation twinning,cross-slip of dislocation,dislocation interaction promoted by cross-slip.
万方数据
维普
