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近年来,在试验室和生产上均已采用了一些新的熔融镁合金的保护气氛。它们不仅比SO_2保护气氛好,而且也胜过工业生产上已采用多年的熔剂。其中最先进的是空气加少量SF_6气氛和CO_2加少量SF_6气氛。应用空气加SF_6最简便,因而能广泛用于1250°F(677℃)下的镁合金压铸的坩埚上,由于CO_2气氛能在熔融金属表面形成一层薄的保护膜,特别是在高达1600°F(871℃)的温度和甚至更高温度下仍能存在,因而CO_2/SF_6气氛能在较高温度下的合金配制、精炼、高温加热、砂型铸造等操作过程中得到广泛的应用。
In recent years, a number of new protective atmospheres of molten magnesium alloys have been used both in the laboratory and in production. Not only do they provide a better atmosphere than SO2, they also outperform those that have been used for many years in industrial production. One of the most advanced is the air plus a small amount of SF_6 atmosphere and CO_2 plus a small amount of SF_6 atmosphere. The simplest application of air plus SF_6 allows it to be used extensively in magnesium alloy die-cast crucibles at 1250 ° F (677 ° C) because of the CO_2 atmosphere which forms a thin protective film on the molten metal surface, especially at temperatures up to 1600 ° F (871 ℃) temperature and even higher temperatures can still exist, so CO_2 / SF_6 atmosphere at higher temperatures in the alloy preparation, refining, high temperature heating, sand casting and other operating procedures are widely used.