The Influence of the Conditions of Casting on Piping and Segregation, as Shown by Means of Wax Ingots

THIS paper presents an experimental verification of some of the predictions made by one of us' concerning 'the influence of certain conditions of casting upon the size and position of the pipe', and the position of the segregate, in steel ingots. The predictions which we have been able to verify are the following A. That the pipe is shortened and the segregate raised 1. By slow casting; 2. By casting with the large end up instead of down; 3. By retarding the cooling of the top, e.g., by means of a sinking-head. B. That the pipe is shortened by slow cooling. C. That the pipe and segregate lie in the last freezing-part. Our procedure was to cast ingots of wax (commercially pure stearic acid) containing a little bright green copper oleate (usually 1.5 per cent.) under varying conditions; to saw each ingot open along a longitudinal plane passing through its axis ; and to examine the longitudinal section thus laid bare. In order to make the segregate or enriched part more distinct in color from the impoverished part, a very little red cerasine was added. An experiment which will be described later showed that the cerasine itself does not segregate markedly, if at all. Hence we may assume that the strong contrasts between the green and red shown in so many of our ingots are due, not to segregation of cerasine, but to that of the green oleate, in the wax which in itself is uniformly reddened with cerasine.