| 摘要 |
PURPOSE:To provide a stalk for low pressure casting which is highly resistant to erosion by molten metal, and reduces the change in the components of the molten metal to be caused by the erosion of the stalk and the fraction defective of castings occuring therein by forming the parts of the stalk in contact with the molten metal of a metallic Ti pipe. CONSTITUTION:In a low pressure casting device, the stalks 5 to be inserted into molten metal 4 such as Al alloy in a crucible 3 are formed in the following way: Each stalk 5 is formed of a metallic Ti outside wall pipe 8 and a metallic Ti inside wall pipe 9, and the inside parts of the double ply pipes are formed into one body by vacuum insert casting. Or the stalk 5 is formed into the segmental interchangeable type wherein the lower left section of the stalk 5 is formed of a thick-walled metallic Ti pipe 13 and the lower right section of thin- walled double ply metallic Ti respectively or the stalk is formed into one body type wherein only the parts in contact with molten metal are made of thin- walled double-ply metallic Ti pipes. Here, 1 in the figure denotes a refractory heat insulating vessel, 2 a heater, 15 an intermediate stalk and 7 a pipe of pressurized air for feeding the molten metal into metallic molds, respectively. |
