Stray grain formation, thermomechanical stress and solidification cracking in single crystal nickel base superalloy welds
Stray grain formation, thermomechanical stress and solidification cracking in single crystal nickel base superalloy welds
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DOI：
10.1179/136217104225021841
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发表时间：
2004-12
影响因子：
3.3
通讯作者：
J. W. Park;J. Vitek;S. Babu;S. David
中科院分区：
文献类型：
--
作者：
J. W. Park;J. Vitek;S. Babu;S. David
本文研究了镍基单晶高温合金焊缝中杂散晶粒的形成和热机械应力对凝固裂纹的影响。在三种不同的加工条件下，以不对称的晶体学取向进行焊接。随着焊接速度和功率的增加，杂散晶粒的形成变得广泛，但仅在焊缝的一侧。凝固裂纹也变得更加广泛，并且主要沿着游离晶界发生。采用有限元法对这三种焊接工艺进行了模拟。计算结果表明，热机械应力随焊接速度和焊接功率的增加而增加，导致裂纹敏感性增加。这些结果与实验观察相符。
In the present study, the effects of stray grain formation and thermomechanical stresses on solidification cracking in welds of single crystal Ni-base superalloys have been investigated. Welds were made in an asymmetric crystallographic orientation under three different processing conditions. As welding speed and power increased, stray grain formation became extensive, but only on one side of the weld. Solidification cracking also became more extensive and occurred mostly along the stray grain boundaries. The three welding processes have been simulated using the finite element method (FEM). The calculation results showed that thermomechanical stresses increase with welding speed and power, leading to increased susceptibility to cracking. These results agree well with experimental observations.