Plastic instability behavior of bcc and hcp metals after low temperature neutron irradiation

Effect of irradiation-induced plastic flow localization on ductile crack resistance behavior of a 9%Cr tempered martensitic steel

“…Above about 1 dpa, plastic instability becomes evident, characterized by a premature necking occurring shortly after the yield strength is reached. This observation is typical of many materials experiencing dislocation channel deformation [6,9,[12][13][14][15]29,[41][42][43][44][45][46][47].…”

“…The mechanical response of a material experiencing plastic flow localization is characterized by a softening shortly after the yield strength. The TEM observations clearly show narrow defect-free channels or bands is which plastic deformation occurs preferentially [6,9,12,13,[16][17][18][19]. Recently, a number of computer simulations including molecular dynamics were also reported to better understand this phenomenon [20][21][22][23][24].…”

“…Indeed, in these bands, defect clearing by the initial unpinned dislocations provides paths of easy glide for subsequent dislocations, promoting therefore a localized plastic deformation. This phenomenon was observed in bcc, fcc and hcp metals [2,[5][6][7][8]. A number of investigations are being devoted to this phenomenon [6][7][8][9][10][11][12][13][14][15], from both macroscopic and microscopic aspects, i.e., tensile testing and transmission electron microscopy (TEM), respectively.…”

Deformation-induced martensite formation and dislocation channeling in neutron-irradiated 316 stainless steel

“…Low temperature neutron irradiation often results in a decrease in tensile ductility, leading to the loss of strain hardening capacity, especially at higher doses (>0.1 dpa) [1][2][3][4]. These mechanical property changes are usually attributed to the presence of irradiation-induced defect clusters such as black dots, faulted dislocation loops (Frank loop), and stacking fault tetrahedra (SFT), that act as obstacles to dislocation motion during deformation.…”

Low-temperature mechanical and magnetic properties of the reduced activation martensitic steel

“…The increase of YS and UTS with decreasing temperature in the RAM steels could be attributed to the refinement of martensitic laths [15], because the refined martensitic laths can prevent dislocation movement and crack propagation, at the same time they can bear higher internal stress and make the internal stress distribute more uniformly. The increase of ductility with decreasing tempera- Fig.…”