Grain Refining and Cracking During Solidification

Grain refining is of practical interest in welding, casting, and additive manufacturing. Despite extensive studies, it is still not very clear why grain refining can decrease the susceptibility to cracking during solidification and why over grain refining can increase it. To help understand why, the present study included the continuity of the interdendritic liquid and solute poisoning into consideration. The present study also attempted to estimate the decrease in the cracking susceptibility caused by grain refining. To do this, a simple index for the cracking susceptibility was modified by the extent of grain refining. The validity of the estimation was checked against cracking susceptibility tests in welding and casting.