【摘要】 渗氢后,氢含量约为220μg/g左右的Zr-4、Zr-2管和Zr-4板,在周向张应力为70～180MPa(Zr管)或张应力为55～180MPa(Zr-4板)作用下,在150～400℃温度区间进行循环。研究了应力和温度循环次数对氢化物再取向程度的影响。随着应力增大和温度循环次数增加,氢化物再取向程度也增大,但是氢化物发生再取向存在应力阈值。应力阈值与温度循环次数有关,当张应力低于应力阈值时,氢化物应力再取向不明显;当应力大于应力阈值时,氢化物应力再取向程度随着与应力、温度循环次数增加而增大。Zr-4管中氢化物发生再取向时,首先从管壁外表面开始,逐渐向内推进,这可能与内、外表面织构不同有关。织构不仅对应力阈值有影响,而且也影响B值,因此控制织构仍可以制约氢化物发生应力再取向。更多还原

【Abstract】 Under the conditions of circumferential tensile stress from 70 to 180 MPa for Zircaloy tubes or the tensile stress from 55 to 180 MPa for Zircaloy-4 plates and temperature cycling between 150 and 400C ,the effects of stress and the number of temperature cycling on hydride reorientation in Zircaloy-4 tubes and plates and Zircaloy-2 tubes containing about 220g/g hydrogen have been investigated. With the increase of stress and/or the number of temperature cycling, the level of hydride reorientation increases. When hydride reorientation takes place, there is a threshold stress concerned with the number of temperature cycling. Below the threshold stress, hydride reorientation is not obvious. When applied stress is higher than the threshold stress, the level of hydride reorientation increases with the increase of stress and the number of temperature cycling. Hydride reorientation in Zircaloy-4 tubes develops gradually from the outer surface to inner surface. It might be related to the difference of texture between outer surface and inner surface. The threshold stress is affected by both the texture and the value of B . So controlling texture could still restrict hydride reorientation under tensile stress.更多还原