核安全级DCS设备危险频率下的电接触摩擦学特性

Tribological Performance of Electrical Contacts at Risk Frequency ofNuclear Safety Level DCS Equipment

为研究核安全级分布式控制系统(DCS)设备中的电接触摩擦学特性,对核安全级DCS设备的危险频率进行了评估。建立了一套球面电接触摩擦学试验装置,在危险频率下进行了一系列载流摩擦学试验,探索不同电流作用下界面摩擦磨损特性。研究结果表明,核安全级DCS设备的危险频率为12 Hz;在该频率下,随着输入电流从1 A增大至3 A,摩擦因数呈现先减小后增大的趋势;在大电流作用下,电接触达到失效的时长显著增长;电接触界面表现出划痕、颗粒、微裂纹、磨屑堆积和磨屑飞溅等5种特征;虽然接触区域存在一定的氧化产物,但是只要有足够多的接触区域实现导电通路,界面依然能够保持良好的电接触状态。

To study the tribological characteristics of electrical contacts in nuclear safety level DCS equipment,the risk frequency of the equipment was evaluated.A set of ball-on-flat tribological test apparatus was established to conduct a series of current-carrying friction tests at the risk frequency.The interfacial friction and wear characteristics under different input electric currents were investigated and the results show that the risk frequency of the nuclear safety level DCS equipment is as 12 Hz.At this frequency,as the input current increases from 1 A to 3 A,the friction coefficient shows a trend of decreasing first and then increasing.Under high-current conditions,the duration until electrical contact failure significantly increases.The electrical contact interfaces exhibit five features:scratches,particles,micro-cracks,debris accumulation and splashing.Although there are some oxidation products in the contact areas,as long as there are enough contact areas to achieve conductivity path,the interface may still maintain good electrical contact status.