合金覆层厚度对反应堆压力容器用金属C型环密封性能的影响

EFFECT OF THE THICKNESS OF ALLOY LINING ON SEALING PERFORMANCE OF REACTION PRESSURE VESSELS METAL C-RING

赋能型金属C型密封环是保障核电站安全运营至关重要的基础部件,其组成部件之一的合金覆层的厚度将会影响C型环的密封性能。在建立C型环三维弹塑性有限元分析模型的基础上,通过实验验证了理论模型的可靠性,详细分析了合金覆层厚度对C型环力学性能和密封性能的影响。结果表明:在同一压缩量下,合金覆层越厚C型环刚度略大但它对回弹特性无明显影响;而合金覆层厚度过小时,塑性应变值较大,不利于C型环的密封;相反,合金覆层厚度越大,接触应力分布也越均匀,但过厚的合金覆层会导致密封面起皱;对于百万千瓦级核反应堆压力容器(RPV)用金属C型密封环,为保证良好的密封效果,工程上宜推荐合金层厚度在0.5 mm^0.7 mm范围内才能确保C型环具备较好的密封性能。

Spring energized metal C-ring is an important basic component which is crucial to ensure the safety of nuclear power plant operation. The thickness of alloy lining which is one of the component part of metal C-ring will affect the sealing performance of C-ring. This article has built C-ring three-dimensional elastic-plastic finite element analysis model. Based on the reliability of the theoretical model which is verified by the experimental study,thickness of alloy lining on the mechanical behavior and sealing performance of C ring are discussed. The results show that under the same amount of compression,the thicker the alloy lining,the larger C ring stiffness slightly. But it has no obvious effect on the springback characteristic of C ring.When alloy lining thickness is small,the plastic strain value is higher which is adverse for the sealing performance. On the contrary,the greater thickness of alloy lining,the more uniform contact stress distribution,but too thick alloy lining can lead to sealing face wrinkles. So for millions of kilowatt nuclear reactor pressure vessel（ RPV） with a metal C ring,in order to ensure that metal C ring has good sealing performance,alloy lining thickness value of 0. 5-0. 7 mm should be recommended in the project,in order to ensure the sealing performance of C ring.