摘要
以单晶炉壁热应力为研究对象,分析了单晶炉观察窗焊接接头冷却水泄漏机理,建立了三维稳态温度场和弹塑性应力场有限元模型,对十二种组合结构的观察窗进行了工作热应力模拟,比较了平面和椭圆型炉盖封头、长条形和方圆形观察窗焊缝的热应力状态,探讨了形状、单双面焊接和温度对热应力影响趋势。结果表明,内外壁横截面均为正方形或矩形的两种窗形焊缝的热应力极值最大;增加副焊缝成为双面焊时,主焊缝的应力分布几乎没有变化,新增加的焊缝约束对其影响甚微;工作温度越高,焊缝的热应力越大。因而,宜选用圆形窗或者内壁带圆弧的长条窗,施加双面焊,避免窗体冷却水温超过规定值。这些措施成功解决了观察窗在样机试验时能正常工作,出厂使用时寿命短频繁漏水的问题。
The thermal stress of single crystal furnace wall is studied on,the leakage mechanism of cooling water in welded joint of observation window of single crystal furnace is analyzed,a three-dimensional finite element model of steady-state temperature field and elastic-plastic stress field is established,the working thermal stress simulation of twelve observation windows of constituted structures is carried out,the thermal stress states of the weld seams of the flat and elliptical cover,the long strip and the square circular observation window are compared,the influence of shape,single-sided and double-sided welding and temperature on thermal stress is discussed.The results show that the extremum of thermal stress in the weld seams of two kinds of window shape with square or rectangular cross-sections on both inner and outer walls is maximum,the stress distribution of the main weld seam is almost unchanged,and the new weld restraint has little effect on it when double-sided weld is becomed by adding the auxiliary weld seam,the higher the working temperature is,the greater the thermal stress of the weld is.Therefore,it is advisable to choose a circular window or long window with arc on the inner wall,double-sided welding is applied and it is avoided that cooling water temperature of window body exceeds specified value.These measures have successfully solved the problem that the observation window of the single crystal furnace works well in the experiment on a prototype,but the service life is short and the water leakage is frequent when it is used in factory.
作者
高利强
GAO Li-qiang(Engineering Training Center,Xi’an University of Technology,Xi’an 710048,China)
出处
《人工晶体学报》
EI
CAS
北大核心
2019年第11期2038-2049,2061,共13页
Journal of Synthetic Crystals
关键词
单晶炉
观察窗
数值模拟
工作热应力
single crystal growth furnace
observation window
numerical simulation
working thermal stress
