P-RE-Sr变质细化A390铝合金及其重熔过程的组织演变

Structural Evolution of A390 Alloy Remelting Process with P-RE-Sr Metamorphic Thinning

首先研究了P、RE和Sr复合变质细化A390合金,结果表明,用P-RE-Sr三元复合变质对合金组织细化效果最佳,合金中初晶硅平均尺寸为20μm,棱角圆滑且分布均匀,共晶硅为细小的颗粒状.其次,研究该合金在不同复合变质重熔过程中的组织演变,结果显示,先添加P,RE再加Sr的三元复合变质重熔效果均比其他复合变质重熔效果好,在重熔时间较短（30-60 min）时,初晶硅尺寸为20-25μm,共晶硅多数为颗粒状或短杆状存在.

The paper introduces that the effect of P、RE、Sr composite modifier and modification on the structure of A390 alloy. The results show that P-RE-Sr ternary combination modification effect is best. The average size of primary silicon is 20 μm and the edges and corners are smooth and well-distributed in the alloy. Eutectic silicon is fine granular. At the same time,the research also show that the alloy is microstructure evolution on metamorphic remelting process of the different of P,RE,Sr composite modifier and modification.The result reflects that the first addition of inoculant P、RE and then Sr are better than others. When the remelting time is shorter（ 30 - 60 min）,the primary silicon size is maintained at 20 - 25 μm,and most of the eutectic silicon morphology are particles or short rods in the alloy.