Formation of macrosegregation of 5 t steel ingots cast in sand molds with and without water-cooled copper tube is simulated by solving macroscopic mass, momentum, species and energy conservation equations with the con...Formation of macrosegregation of 5 t steel ingots cast in sand molds with and without water-cooled copper tube is simulated by solving macroscopic mass, momentum, species and energy conservation equations with the consideration of shrinkage formation. Predicted macrosegregation pattern of the ingots shows a fair agreement with the experimental data. Both calculations and experiments reveal that some positive segregation patches are formed at the bottom of ingot. With the water-cooled copper tube inserted in the sand mold, the ingot cast has a less intensive macrosegregation. Mechanisms of macrosegregation formation are numerically analyzed. Explanations regarding the influences of fluid flow and temperature change upon the segregation formation are provided.展开更多
The quality of semi-products of platinum metals and alloys, produced by way of plastic working, essentially depends on or, in many cases, is completely determined by the quality of ingots. Plastic working does not mak...The quality of semi-products of platinum metals and alloys, produced by way of plastic working, essentially depends on or, in many cases, is completely determined by the quality of ingots. Plastic working does not make it possible to eliminate or localize metallurgical defects. In many cases it promotes the occurence thereof. Low-rate casting with directional crystallization can ensure the production of dense ingots free of non-metallic inclusions, shrinkage and gas weakness, with observance of certain temperature/rate modes. After comparative tests of vertical and horizontal molds, preference has been given to horizontal water-cooled molds, allowing to cast all alloys in the conditions of directional crystallization.展开更多
基金supported by "High-end CNC machine tools and basic manufacturing equipment" Major Science and Technology Project of China(No.2009ZX04014-081)Post-Doctor Project of China (No.20080431162)Young Expert Science Foundation of Harbin University of Science and Technology(No.2008XQJZ005)
文摘Formation of macrosegregation of 5 t steel ingots cast in sand molds with and without water-cooled copper tube is simulated by solving macroscopic mass, momentum, species and energy conservation equations with the consideration of shrinkage formation. Predicted macrosegregation pattern of the ingots shows a fair agreement with the experimental data. Both calculations and experiments reveal that some positive segregation patches are formed at the bottom of ingot. With the water-cooled copper tube inserted in the sand mold, the ingot cast has a less intensive macrosegregation. Mechanisms of macrosegregation formation are numerically analyzed. Explanations regarding the influences of fluid flow and temperature change upon the segregation formation are provided.
文摘The quality of semi-products of platinum metals and alloys, produced by way of plastic working, essentially depends on or, in many cases, is completely determined by the quality of ingots. Plastic working does not make it possible to eliminate or localize metallurgical defects. In many cases it promotes the occurence thereof. Low-rate casting with directional crystallization can ensure the production of dense ingots free of non-metallic inclusions, shrinkage and gas weakness, with observance of certain temperature/rate modes. After comparative tests of vertical and horizontal molds, preference has been given to horizontal water-cooled molds, allowing to cast all alloys in the conditions of directional crystallization.
