Effect of Addition Ratio of Recycled Material on Composition and Properties of GH4169 Alloy

GH4169 alloy was smelted with three return ratio of 70% chip, 70% block, 25% block + 45% chip. Chemical composition and mechanical properties of the smelted alloy were analyzed and compared with the new compound GH4169. The results show that the nitrogen content of the three returned alloys is basically the same but higher than that of the new alloy, and the oxygen content of the three returned alloys reaches the level of the new alloy. The size and quantity types of inclusions smelted by three kinds of return alloy are basically the same, which are slightly higher than those smelted by new alloy. The nitrides in return alloy are mainly TiN, NbN and inclusions, and single-layer composite inclusions Ti(C,N)–NBC and multilayer complex inclusions (Mg, Al) O–Ti (C, N)–(Mo, Nb). The strength of the three return alloys is similar to that of the new alloys at room temperature and 650 ℃. At 650 ℃/725 Mpa, the durability of the alloy is much higher than the technical requirements and close to the new material alloy.