Experimental evidence of liquid feeding during solidification of a steel

Sufficient liquid feeding under constrained solidification conditions like, those experienced in welding and casting, is vital to avoid solidification cracking. We present the results of unique in-situ experimental observations of liquid feeding in a solidifying steel melt pool. Liquid feeding was observed in the inter-cellular regions during the terminal stage of solidification. An average liquid flow speed of 450–500 μm s−1 was found. A pressure difference of the order of 104 Pa is calculated to cause the liquid flow. The rate of solidification shrinkage and the rate of deformation were found to be less than the rate of liquid feeding.