Ⅰ型载荷下缺口前端氢浓度分布的研究

DISTRIBUTION OF HYDROGEN CONCENTRATION NEAR NOTCH TIP UNDER MODE I LOADING

采用离子探针微分析仪,对Ⅰ型载荷下21Cr9Ni9MnN奥氏体钢缺口前端氢浓度分布进行了研究。结果表明,缺口前端存在两个氢浓度的富集峰,一个位于缺口顶端,另一个距缺口稍远。缺口顶端的氢富集峰是位错对氢陷阱作用结果,而静水应力导致远离缺口的氢富集峰。对缺口前端氢的富集过程以及应力强度因子对氢浓度分布的影响进行了讨论。

The distribution of hydrogen concentration near the notch tip of theaustenitic steel 21Cr9Ni9MnN under model Ⅰ loading has been studied by Ion Micro-probe Mass Analyser. Experimenial results show that two peaks of hydrogen accu-mulation, one at notch tip and other far apart from it, are found. The distributionof hydrostatic stress and plastic strain in front of the notch tip under planar stresscondition was calculated using ADINA non-linear finite element method. The calcu-lated result in comparison with data measured showed that the hydrogen concentra-tion peak at the notch tip is caused by trapping effect of dislocation on dissolvedhydrogen, while the other from the hydrostatic stress. The influence of stress in-tensity factor on the distribution of hydrogen concentration and the process of hy-drogen accumulation near notch tip was also discussed.