储氢床不锈钢疲劳寿命预测及棘轮效应和应变强化竞争机理描述

Prediction of Fatigue Life of Hydrogen Storage Bed Stainless Steel and Description of Ratchet Effect and Strain Strengthening Competition Mechanism

摘要: 开发具有高效、安全的氢同位素储存与供给技术的储氢床对国际热核聚变实验反应堆(ITER-International Thermonuclear Experimental Reactor)和中国聚变工程实验堆(CFETR-Chinese Fusion Engineering Testing Reactor)的发展和应用尤为重要。储氢床中316L (N)不锈钢的功能是结构支承和传热散热，对其在循环载荷作用下进行稳定性评价关系到整个储氢系统的安全，引起学术界高度重视。根据现有的应力循环条件下的疲劳寿命实验结果，以BP神经网络算法建立了疲劳寿命模型，编制了相应的Matlab代码预测疲劳寿命，并与现有的本构预测模型(Basquin-Coffin-Manson模型、SWT模型和模型三)进行对比，结果表明：BP神经网络的预测结果与实验数据吻合良好，优于现有的本构模型，并解释了非对称应力循环条件下，平均应力强化和棘轮效应对疲劳寿命影响的竞争机制。论文还对疲劳蠕变寿命进行了预测，得到的预测结果与实验数据吻合良好。本文提供的方法和获得的数据对于储氢床设计和安全运营具有重要的参考价值。

Abstract: The development of hydrogen storage bed with efficient and safe hydrogen isotope storage and supply technology is particularly important for the development and application of ITER (Interna-tional Thermonuclear Experimental Reactor) and CFETR-Chinese Fusion Engineering Testing Re-actor. In hydrogen storage bed, 316L (N) stainless steel plays an important role in structural sup-port and heat transfer and heat dissipation. The stability evaluation of the 316L (N) stainless steel under cyclic load is related to the safety of the whole hydrogen storage system, which has drawn great attention from the academic circle. Based on the existing stress cycle fatigue life under the condition of the experimental results, the fatigue life model is established by the BP neural network algorithm, the corresponding Matlab code compiled to predict the fatigue life, and with the existing constitutive model (Basquin-Coffin-Manson, SWT model and new model) is compared, the results show that the BP neural network prediction results are in good agreement with the experimental data, better than the existing constitutive model, and explained under the condition of asymmetrical stress cycling, the average stress intensification and ratchet effect influence on fa-tigue life of the competition mechanism; the fatigue creep life is also predicted and the predicted results are in good agreement with the experimental data. The methods and data obtained in this paper are of important reference value for the design and safe operation of hydrogen storage beds.