核电厂反应堆主泵主轴疲劳可靠性试验与评估

Fatigue Reliability Test and Evaluation of Main Pump Spindle of Nuclear Power Plant Reactor

为了获得给定置信度、不同可靠度下的核电厂反应堆主泵主轴材料疲劳可靠性数据,制造了一段内外径尺寸、加工工艺与产品主轴完全相同的模拟轴用于取样,测试了常温光滑、常温焊接、常温缺口、高温光滑、高温焊接、高温缺口6种试样的疲劳寿命;应用可靠性统计方法分别确定了置信度为0.9、0.95时,在不同可靠度下6种试样的疲劳可靠性寿命置信下限方程以及6种试样的可靠性疲劳极限;分析了试样与主轴疲劳寿命的区别与修正方法,利用修正后的试样数据对主轴疲劳失效的薄弱环节进行可靠性评估。结果表明,置信度为0.9、0.95时,主轴在寿期内不发生疲劳失效的可靠度超过0.9999。本研究实现了反应堆主泵主轴疲劳失效更为准确的可靠性评估。

In order to obtain the fatigue reliability data of the main spindle material of the nuclear power plant reactor under a given confidence level and different reliability levels,a simulation spindle with the same inner and outer diameter dimensions and processing technology as the product spindle was manufactured for sampling.The fatigue lives of six kinds of specimens including room temperature smooth,room temperature weld,room temperature notch,high temperature smooth,high temperature weld and high temperature notch were tested.The lower confidence limit equation of the fatigue reliability life with different reliability levels and the reliability fatigue limit of the six kinds of specimens were determined by reliability statistical methods when the confidence level was 0.9 or 0.95.The differences and revised methods between the fatigue life of the specimens and the spindle were analyzed.Using the revised specimen data,the reliability assessment of the spindle fatigue failure weak links were carried out.The results show that the reliability of the spindle without fatigue failure during the lifetime exceeds 0.9999 when the confidence level is 0.9 or 0.95.In this paper,a more accurate reliability assessment of spindle fatigue failure of reactor main pump is achieved.