China's original standards for casting zinc alloys (GB 3062-1982. GB 1175-1974) have not been adapted to the needs of the development of cast zinc alloys. The National Foundry Standardization Technical Committee completed the zinc alloy die-casting and zinc casting in 1992 and 1997 respectively. Alloy standard repair work, the newly revised standards ((GB/T 1175-1997, GB/T 13818-199 referenced the relevant standards of the United States and Germany, casting zinc alloys, see Table 14-1. Four, casting zinc Characteristics and Applications of Alloys The characteristics and uses of cast zinc alloys are shown in Table 14-2. Section 2. Smelting Process of Zinc Alloys The smelting temperature of zinc alloys is low. Various smelting equipments for smelting aluminum alloys can be used for smelting zinc alloys. Also long, Pb and Sn seriously reduce the corrosion resistance of zinc alloys, so it should be strictly separated from the citrus vortex of smelting copper alloys. ZA series alloys are easy to infiltrate iron and should be coated with the smelting tool when the cast mandarin is used.
Due to the low smelting temperature, zinc itself has a large vapor pressure, low gas content, low refining requirements compared to aluminum alloys, sometimes no refining, and low melting losses of 1% to 2%. Castings can be refined by standing, chlorine salt treatment, inert gas, and filtration. The most widely used is the chlorine salt refining, with the bell jar pressed at 450-470°C into 0.1%--0.2% or hexachloroethane 0.3%-0.4%, which can remove nearly 80% of the zinc alloy's oxide inclusions and About 70% of impurities, such as FeA13 and so on.
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