Bucket Teeth Shell Layers
The shape and structure of the cast of different layers of shell, there will be differences. For example, with elongatedslot casting Kong Huo need to do two or three times the surface layer; the general casting two times to do the backing layer is enough, and the relatively large castingsmay require three or more layers. Cost of shell castings per kilogram is about 5.9 yuan, of which the material costs accounted for 67.8%, fuel and poweraccounted for 23.9%,accounted for 13.3% of wages. In the 4 yuan / kg of shellmaterial, zircon sand andzirconium powder consumptionaccounted for 63%, accounted for the entire cost of shell42.7%, silica sol costs accounted for about 12.2% of the cost of making shell. Although the zircon zirconium powderwas used for the surface layer.
The invention discloses a casting method of a bucket tooth shell mold, which is applied to the field of casting. The method comprises the steps of sand box molding and vibration pouring, wherein the sand box molding comprises the steps of upper and lower box molding, box assembling, covering of an insulating layer and the like; and (3) manufacturing a shell mold and a sealing case with the thickness not more than 3mm in a horizontal metal mold, removing the upper metal mold, replacing the upper metal mold with a case body, checking the shell mold, repairing a local unformed part with precoated sand, and ensuring that the sand box is vacuumized and airtight. Adding steel shots into the box body, covering an agricultural film, vacuumizing, and demolding from the lower metal mold to finish the molding of the upper box and the lower box; and (3) lower core assembling, and covering quartz sand or heat-insulating cotton heat-insulating layers on the top surface and the periphery of the sand box. And (3) when pouring, the sand box is in a vacuum state, the vibration is immediately carried out after pouring, and the vibration is stopped before the vacuum is removed. By adopting the casting method, the usage amount of the precoated sand is greatly reduced, as-cast crystal grains of the wear-resistant part are refined, the generation of cracks is avoided, and the energy consumption of heat treatment is reduced.