Reply to Discussion of “Observation of the Mold Filling Process of a Large Hydro-Turbine Guide Vane Casting”

Excerpt

We appreciated Professor John Campbell’s comments very much. The mold filling of liquid metals is very important, especially as the first step of making a casting. Therefore, the filling system design is a very serious work. The melt filling process has been a 1000-year mystery because it cannot be directly observed because of the mold obstacle. So, researchers have resorted to water analogy system. However, the analog results have been always doubted. In recent years, the X-ray observation method unveiled the filling process for specimens or small castings in laboratories. But, still some problems need to be solved such as dealing with the complicated and large castings. In our paper, we highlighted the effective direct observation system of mold filling and its successful application in a 10 t heavy steel casting, i.e., the using of high temperature-resisted camera to directly observe the filling process of heavy steel castings weighing in tons, which is affordable and the liquid steel flow can be directly watched at real time. It is a very valuable method for foundries, especially for the production of heavy castings, the direct observation means optimization of filling system and finally reducing waste and improving casting quality. Up to now, this method have been used in seven new heavy castings in the foundry of Harbin Electric Machinery Co., Ltd., and some observation results approve the experience, while some are in contradiction with the experience. …