For straight columnar dendritic grains growing side by side, |dT/d(f_S)^1/2| (T: temperature; f_S: fraction solid) near their roots can be the crack-susceptibility index as verified against welds made with an elliptical weld pool. This study showed the index is also valid for welds made with a teardrop-shaped pool. In both cases, at the mushy-zone centreline, the tips of such grains grow and finally become the roots as the mushy-zone moves forward. This validity is consistent with: (1) the crack-susceptibility ranking of alloys in arc welding (typically elliptical pool) being similar to that in laser- or electron-beam welding (typically teardrop-shaped pool), and (2) the ranking calculated based on the index being consistent with that observed in laser- or electron-beam welding.

对于并列生长的直柱状树枝状晶粒，| |。dT / d（f _S）^1/2 | （T：温度; f _S：在其根部附近的固体分数）可以作为裂纹敏感性指数，已通过椭圆形焊缝对焊缝进行了验证。这项研究表明，该指数对于使用水滴状熔池进行的焊接也是有效的。在这两种情况下，在糊状区的中心线，这种谷物的尖端都生长，并最终随着糊状区的前进而成为根。该有效性与以下方面相符：（1）电弧焊（通常为椭圆形熔池）中的合金的裂纹敏感性等级与激光或电子束焊接（通常为滴状熔池）中的合金相似，以及（2）等级根据与激光或电子束焊接中观察到的指标一致的指标进行计算。