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一、焊接铸铝件的特点1.产生氧化铝膜(Al_2O_3)这层氧化膜不仅比重大,而且它的熔点温度高达2030℃。铝的熔点仅658℃,沸点1800℃,在焊接过程中不断产生氧化铝。这种氧化铝越多,越难熔化和破碎,也不易浮于熔池表面。因此,焊接速度不宜太慢。2.由固态转变为液态时无塑性过程当焊接温度达到350～380℃时,铝的强度最低,升温到熔化温度时,它的强度完全消失,以致不能支持自身重量而弯曲。3.铝在加热时颜色不变(仍是银白色)这样焊工就不能以金属的颜色变化来判断加热温度的高低,工件厚度不匀时,更难以掌握,很容易造成塌块。
First, the characteristics of welded cast aluminum 1. Alumina film (Al_2O_3) This layer of oxide film is not only large, and its melting point temperature up to 2030 ℃. The melting point of aluminum is only 658 ℃, the boiling point of 1800 ℃, continue to produce alumina in the welding process. The more alumina, the more difficult to melt and broken, it is not easy to float in the pool surface. Therefore, the welding speed should not be too slow. 2. Non-plasticity from solid state to liquid state When the welding temperature reaches 350-380 ℃, the strength of aluminum is the lowest. When the temperature reaches the melting temperature, its strength completely disappears, so that it can not support its own weight and bend. 3. Aluminum in the color of the same heating (still silver) so that the welder can not change the color of the metal to determine the level of heating temperature, the workpiece thickness uneven, more difficult to grasp, it is easy to cause collapse.