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高钛低铝型高温合金是用于现代航空、火箭发动机以及燃气轮机的重要合金材料,该合金在电渣重熔过程减少合金中钛的烧损和均匀控制钛含量分布是当时国内外尚未解决的技术难题。 通过实验研究,查清了该类型合金中钛烧损机理,发现钛烧损主要与渣中TiO_2含量有关,渣中Al_2O_3、TiO_2对钛有氧比作用,与钛平衡的是渣中Ti_3O_5,Ti_3O_5又会被大气氧化成TiO_2;减少钛烧损的关键在于化渣过程使渣中部分TiO_2还原为Ti_3O_5,并在重熔全过程保持一定量的Ti_3O_5。此外,发现MgO在渣中可提高Ti_3O_5和Al_2O_3的活度系数同时又能降低渣中TiO_2的活度系数,从而减少钛的烧损。研制出了该类型不同牌号合金电渣重熔相适应的CaF_2—Al_2O_3—MgO—TiO_2渣系。另一方面利用上述机理研
High titanium low-aluminum superalloy is an important alloy material used in modern aviation, rocket engine and gas turbine. The alloy is not soldered at home and abroad at the time when the titanium in the alloy is reduced during the ESR process and the titanium content is uniformly controlled technical challenge. Through the experimental study, the mechanism of titanium loss in this type of alloy was investigated. It was found that the loss of titanium was mainly related to the content of TiO 2 in the slag. The effect of Al 2 O 3 and TiO 2 on the ratio of oxygen to titanium in the slag and the balance of Ti 3 O 5 and Ti 3 O 5 Which will be oxidized by atmospheric air into TiO_2. The key to reduce the burning of titanium is to reduce some TiO_2 in the slag to Ti_3O_5 and to maintain a certain amount of Ti_3O_5 in the whole process of remelting. In addition, it was found that MgO can increase the activity coefficient of Ti 3 O 5 and Al 2 O 3 in slag while reducing the activity coefficient of TiO 2 in slag, thus reducing the burning of Ti. The CaF_2-Al_2O_3-MgO-TiO_2 slag system has been developed for this type of alloy electroslag remelting. On the other hand use the above mechanism research