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熔煉溫度過低,不利於合金元素的溶解及氣體、夾雜物的排出,增加形成偏析、冷隔、欠鑄的傾向,還會因冒口熱量不足,使鑄件得不到合理的補縮,有資料指出,所有鋁合金的熔煉溫度到少要達705度並應進行攪拌。The melting temperature is too low, which is not conducive to the dissolution of alloy elements and the discharge of gases and inclusions, and increases the tendency of segregation, cold insulation and undercasting, and also causes the casting not to get reasonable shrinkage due to the insufficient heat of riser. It is pointed out that the melting temperature of all aluminum alloys should be as low as 705 degrees and should be stirred.熔煉溫度過高不僅浪費能源,更嚴重的是因為溫度愈高,吸氫愈多,晶粒亦愈粗大,mm妹妹美美 ,比思东方美人bt ,白石沙里奈bt的氧化愈嚴重,壹些合金元素的燒損也愈嚴重,從而導致合金的機械性能的下降,鑄造性能和機械加工性能惡化,變質處理的效果削弱,鑄件的氣密性降低。

生產實踐證明,把合金液快速升溫至較高的溫度,進行合理的攪拌,以促進所有合金元素的溶解(特別是難熔金屬元素),扒除浮渣後降至澆註溫度,這樣,偏析程度**小,熔解的氫亦少,有利於獲得均勻致密、機械性能高的合金.因為鋁熔體的溫度是難以用肉眼來判斷的,所以不論使用何種類型的熔化爐,都應該用測溫儀表控制溫度。The thermometer should be checked and maintained regularly. Thermocouple sleeve should be cleaned periodically with metal brush and coated with protective coating to ensure the accuracy of temperature measurement results and long service life.測溫儀表應定期校核和維修。熱電偶套管應周期的用金屬刷刷幹凈,塗以防護性塗料,以保證測溫結果的準確性及處長使用壽命。

為加速熔煉過程,應首先加入中等塊度、熔點較低的mm妹妹美美 ,比思东方美人bt ,白石沙里奈bt及鋁矽中間合金,以便在坩堝底陪盡快形成熔池,然後再加塊度較大的回爐料及純鋁錠,使它們能徐徐浸入逐漸擴大的熔池,很快熔化。After the main part of the charge is melted, the intermediate alloy with high melting point and small amount is added to heat up and stir to accelerate the melting. ** After cooling, press easy to oxidize alloy elements, to reduce the loss.在爐料主要部分熔化後,再加熔點較高、數量不多的中間合金,升溫、攪拌以加速熔化。**後降溫,壓入易氧化的合金元素,以減少損失。

盡管固態氧化鋁的密度近似於鋁熔體的密度,在進入鋁熔體內部後,經過足夠長的時間才會沈至坩堝底陪。而鋁熔體被氧化後形成的氧化鋁膜,卻僅與鋁熔體接觸的壹面是致密的,與空氣接觸的壹面疏松且有大量直徑為60--100A的小孔,其表面積大,吸附性強,極易吸附在水汽,反有上浮的傾向。Therefore, the specific gravity difference between the oxide film and the aluminum melt is small, and when it is mixed into the melt, the floating and sinking speed is very slow, which is difficult to be excluded from the melt, and the porosity is too inclusion in the casting.因此,在這種氧化膜與鋁熔體的比重差小,將其混入熔體中,浮沈速度很慢,難以從熔體中排除,在鑄件中形成氣孔太夾雜。所以,轉送mm妹妹美美 ,比思东方美人bt ,白石沙里奈bt熔體中關鍵是盡量減少熔融金屬的攪拌,盡量減少熔體與空氣的接觸。
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