【作者】 孙超； 谭军； 应诗浩； 赵素琼； 孔祥巩；

【Author】 Sun chao Tan jun Ying shihao Zhao suqiong Kong xianggong (National Key Laboratory for Nuclear Fuel and Materials,Nuclear Power Institute of China,P.O.Box 436,Chengdu,Sichuan 610041,PR China)

【机构】 中国核动力院 核燃料及材料国家级重点实验室；

【摘要】 本文研究了N18锆合金(Zr-1Sn-0.3Nb-0.3Fe-0.1Cr)发生氢致延迟开裂(Delayed Hydride Cracking)临界最大开裂温度(T_c)和临界最小止裂温度(T_h)随氢含量的变化规律;同时建立理论模型,对裂纹尖端静水应力和发生DHC的临界氢含量进行了理论分析并对临界温度进行理论预测和计算;结果表明:N18合金发生氢致延迟开裂的临界温度介于相同氢含量下溶解固溶温度与析出固溶温度之间,且最大开裂温度小于最小止裂温度,计算的临界温度值和试验值相当的吻合,因此该理论模型能够真实反映N18锆合金的氢致延迟开裂的物理过程。更多还原

【Abstract】 An experimental study was carded out to determine the critical temperature for initiating and arresting delayed hydride cracking in Zr-Sn-Nb alloy(N18 zirconium alloy).For a given hydrogen content of the specimen,two critical temperatures were observed in this work-a DHC initiation temperature,T_c,at which DHC would initiate when approaching the test temperature from above the solvus(or terminal solid solubility)for hydride dissolution(TSSD)and a DHC arrest temperature,T_h, obtained by heating the same specimen from T_c after DHC had started.Both of T_c and T_h are close to,but below.A theoretical analysis was carded out to quantitatively derive the hydrogen concentration limit and these critical temperatures,a key assumption in the model is that,while the local crack tip stress concentration causes local enhancement of the hydrogen concentration in solution,the hydride precipitation solvus is unaffected by stress.The good agreement obtained between measured and predicted critical temperatures provides strong suppport for this asspumption.更多还原