The effect of dislocation on defects in 316L stainless steel irradiated by helium

Abstract

Inhibition of the movement of helium atoms produced by transmutation reactions under nuclear irradiation can be achieved by intentionally introduced trapping sites such as dislocations in stainless steels. In order to investigate the effect of dislocations in 316L stainless steel on helium irradiationinduced defects, well-annealed 316L stainless steel specimens were cold-rolled to either 10 % or 20 % reduction in thickness and then annealed at 723 K for 1 h, respectively. The non-deformed, 10 % and 20 % deformed specimens were irradiated with helium ions at an energy of 5 keV to a dose of 5 × 10 16 ion/cm 2 under ambient temperature. The effects of dislocations on defects generated by helium ion irradiation and helium desorption with temperature were characterized by slow positron beam Doppler broadening spectroscopy and thermal desorption spectroscopy. The results shows that dislocations have a trend to restrict the migration and aggregation of helium atoms and vacancy-type defects, and also hinder the formation of large helium bubbles.

The effect of different surface treatments of 310S austenitic stainless steel on the corrosion behavior in supercritical water using slow positron methods

“…Highly concentrated dislocation‐type defects are, however, a natural sink for vacancy‐type defects. [ 29 ] Consequently, in PO samples characterized by a relatively lower dislocation‐type defect scale, the survival rate of vacancy‐type defects surpasses that of the other two treated samples. It is generally accepted that the mechanical stresses applied to the samples by the mechanical polishing process are at a shallow depth so that fewer residual stresses and defects form only in the shallow areas compared to the SB and MA samples, and therefore their contribution to the S‐parameters becomes smaller as the depth increases, as shown in Figure 1a, the PO samples have lower and lower S‐parameters compared to the other two samples at deeper depths.…”

Effect of dislocation on helium irradiation defects in low-activation martensitic steel

“…使用中国科学院高能 物理研究所MT3-R2型低能离子注入机对不同形 变 量 下 的 样 品 进 行 室 温 氦 辐 照 , 辐 照 能 量 为 50 keV, 辐照剂量为1×10 17 ions/cm 2 . 采用基于蒙 特卡罗方法的SRIM软件 [16] 模拟He在材料中的 深度分布和位移损伤(见图2). 氦原子和空位的最 大深度分别在350 nm和300 nm, 其峰值在200 nm 和150 nm左右.…”