Technique Of Identifying Graphtite Shape Of Molten Iron On-Spot Based On The Method Fast Testing Surface Tension

Huge rejects are often made because of poor spheroidization in producing nodular and compected graphite cast iron. In order to enhance casting qualification, the graphite shape of molten iron needs forecasting rapidly. At present, all kinds of testing methods can not meet the demands of fast testing.The quality of liquid alloy is a direct and head factor on cast qualification. Surface tension, as of basic physics character of liquid alloy, not only is a token of some interior structure but also affects casting quality. Literatures show that there is a corresponding relation between surface tension and graphite shape of molten iron and this relates to effect of modification. So some quality parameters of molten metal can be predicted by fast testing tension.In this paper, a testing system for fast predicting graphic shape in front of furnace, based on a new method named "amplitude and frequency equivalent of bubbles ", will be introduced in detail. The principle of the new method is to blow air into molten iron through a heat-resistant detector, and then the pressure inside the bubbles, the numbers of blowing bubbles and the diameter of the blowing pipe are measured, and by processing these parameters with proper model, we can get the equivalent which can be used as a token of graphite shape. Single chip microcomputer 80C196KC is adopted as a core of the testing system and keyboard, and the circuits such as LED, micro-printer and relay driving are also used. A serious of operations including loading detector, blowing air and lifting detector, will be carried out automatically under the control of microcomputer. Complex as it is, the whole testing process takes only 5 seconds. Simulated experiments show that the testing system have advantages of friendly operation interface, good agility ,acceptable stability, and high accuracy.