Riser dimensioning-a new approach for grey iron castings

A simplified method for determining minimum size of riser for grey iron castings has been proposed. Dimensioning risers by the proposed method is based on solidification times of risers and castings. Solidification times of risers of different diameters are found out and a graph of solidification times of risers prepared. The solidification times of castings under normal foundry conditions have only to be found out in order to read from the graph of solidification times of risers, suitable sizes of risers to feed the casting. (Mr. G.N. Rao, Scientist and Mr. P.R. Prasad, Senior Research Fellow, National Metallurgical Laboratory)