Effects of mercury on fatigue behavior of Type 316 LN stainless steel: application in the spallation neutron source
Effects of mercury on fatigue behavior of Type 316 LN stainless steel: application in the spallation neutron source
复制标题
汞对316 LN不锈钢疲劳行为的影响：在散裂中子源中的应用
DOI：
10.1016/s0022-3115(03)00116-8
复制
发表时间：
2003
影响因子：
3.1
通讯作者：
L. Mansur
中科院分区：
文献类型：
--
作者：
H. Tian;P. Liaw;J. Strizak;L. Mansur
在空气和汞中，在0.2和10 Hz（R比为-1）以及10和700 Hz（R比为0.1）的频率下，研究了316型不锈钢（SS）的高周疲劳行为，不锈钢是散中子源（SNS）的主要候选靶容器材料。此处R等于疲劳试验期间施加的最小载荷与最大载荷之比。在0.2 Hz时，相对于在空气中的疲劳寿命，观察到在汞中的疲劳寿命降低。相应地，在0.2 Hz的水银中测试的试样的断裂表面上发现沿晶断裂，这是由液态金属脆化（LME）引起的典型断裂模式。在10 Hz和R为-1，700 Hz和R为0.1的疲劳试验期间，观察到机械加工引起的加热，这导致试样温度大幅升高，并且相对于汞的疲劳寿命而言，大应力幅（≤ 210 MPa）下的疲劳寿命较短。然而，在10和700 Hz的疲劳试验中，在空气中冷却的疲劳寿命和在汞中的疲劳寿命似乎是相当的，表明汞的影响很小。因此，在理解316不锈钢在空气和汞中的疲劳行为时，需要考虑试样自热和LME。
The high-cycle fatigue behavior of Type 316 stainless steel (SS), the prime candidate target-container material for the spallation neutron source (SNS), was investigated in air and mercury at frequencies of 0.2 and 10 Hz with a R ratio of −1, and at 10 and 700 Hz with a R ratio of 0.1. Here R equals the ratio of the applied minimum to maximum loads during fatigue experiments. A decrease in the fatigue life in mercury was observed, relative to that in air, at 0.2 Hz. Correspondingly, intergranular fracture was found on the fracture surfaces of specimens tested in mercury at 0.2 Hz, which is a typical fracture mode caused by liquid metal embrittlement (LME). Heating by mechanical working was observed during fatigue tests at 10 Hz and a R of −1, and at 700 Hz and a R of 0.1, which resulted in great increases in specimen temperatures and shorter fatigue lives for large stress amplitudes (⩾210 MPa), relative to those in mercury. However, in the fatigue tests at 10 and 700 Hz, the fatigue lives in air with cooling and those in mercury seemed to be comparable, indicating little influence of the mercury. Thus, both specimen self-heating and LME need to be considered in understanding fatigue behavior of Type 316 SS in air and mercury.