(1) Deformation
The deformation of
nickel alloy tubes mainly adopts forging and rolling processes, and for alloys with poor thermoplasticity, it even adopts rolling after extrusion blanking or direct extrusion process with soft steel ladle. Deformation is to break the cast structure and optimize the microstructure.
(2) Smelting
The smelting of nickel-based alloy tubes is to obtain more purified molten steel and reduce the content of gas and harmful elements. At the same time, due to the presence of easily oxidizable elements such as Ai and Ti in some alloys, non-vacuum smelting is difficult to control. In order to obtain better thermoplasticity , usually smelted in a vacuum induction furnace, or even produced by vacuum induction smelting plus vacuum consumable furnace or electroslag furnace remelting.
(3) Casting
The casting of nickel-based alloy tubes generally uses a vacuum induction furnace to melt the master alloy to ensure the composition and control the gas and impurity content, and at the same time use the vacuum remelting-precision casting method to make parts.
(4) Heat treatment
The heat treatment of nickel-based alloy tubes is divided into solution treatment, intermediate treatment and aging treatment. Taking Udmet 500 alloy as an example, the heat treatment system of this alloy is divided into four stages: solution treatment 1175℃ 2h air cooling; intermediate treatment 1080℃ 4h air cooling; primary aging treatment 843℃ 24h air cooling; secondary aging treatment 760℃ 16h air cooling. In order to obtain the required organizational status and good overall performance.
