Campbell J

Abstract: Professor Campbell had studied gating-system induced turbulence for a number of years. His presentation at the Steel Founders' Society of America's 2000 T&C conference summarized much of his work. It is now well established for many liquid metals that a critical velocity exists such that the surface of the liquid can have sufficient energy to jump high enough and on falling back under gravity, may enfold its own surface. Once this surface has been entrained in this simple way, the entrained double film is now necessarily folded over face to face and a "crack" is/can be formed in the solidified metal. This critical velocity is different for different metal and ranges from 0.6 m/s for magnesium to 0.4 m/s for steel.

Keywords:Steel castings, Gating-system, Surface, Turbulence.