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核主泵主轴一般工作在约300℃的温度环境中,但会频繁受到冷却水的瞬态冲击作用,由此产生的热应力容易导致主轴表面产生疲劳裂纹,有效预测核泵主轴的热疲劳寿命意义重大.本文分析了核泵主轴表面在热冲击过程中的瞬态温度场、热应力场等变化规律,用数值模拟方法研究了热冲击的冲击温度、冲击区域半径和表面吸附水膜厚度等参数对热应力和热疲劳寿命的影响,发现热冲击温度、冲击区域半径和表面水膜厚度各因素对冲击表面热应力和疲劳寿命的影响呈现一定规律性,疲劳裂纹将首先发生在材料表面,然后向内部扩展,到达一定深度后止裂.热冲击冷却水温度差对表面热应力和疲劳寿命影响最大,冲击区域尺寸影响最小,表面吸附水膜具有降低热应力提高疲劳寿命的防护作用.
The main spindle of the nuclear pump generally operates in a temperature environment of about 300 ° C but is frequently subjected to the transient impact of the cooling water. The resulting thermal stress easily causes fatigue cracks on the spindle surface and effectively predicts the thermal fatigue life of the main shaft of the nuclear pump It is of great significance.This paper analyzes the variation law of transient temperature field, thermal stress field and so on during the thermal shock of nuclear pump spindle surface, and studies the impact temperature, impact area radius and surface adsorption water film thickness by numerical simulation Parameters on the thermal stress and thermal fatigue life of the impact and found that thermal shock temperature, impact area radius and surface water film thickness of the impact surface thermal stress and fatigue life of a certain regularity, fatigue cracks will first occur on the surface of the material, And then to the internal expansion, to reach a certain depth after the crack. Thermal shock cooling water temperature difference on the surface thermal stress and fatigue life of the greatest impact on the impact of the size of the smallest area, surface adsorption of water film has the thermal stress to improve the fatigue life protection.