Superalloy, also known as heat-resistant alloy or superalloy, is an important metal material necessary for modern aviation engine, rocket engine, gas turbine and chemical equipment.Capable of withstanding complex stresses at temperatures ranging from 600 to 1100 degrees Celsius for oxidation and gas corrosion, and capable of working reliably for a long time.
At present, iron - base superalloy and nickel - base superalloy are widely used in deformation superalloy. Fe-base superalloy is mainly used as turbine disc, compressor disc, bearing ring combustion chamber and blade. Nickel-based alloys are used in the manufacture of turbine blades, combustors, turbine discs, compressor discs and compressor blades.
The properties of superalloy mainly depend on the composition and microstructure of the alloy. The type, structure, shape, size, quantity and distribution of precipitated phase are particularly important in the structure. The heat treatment of deformed superalloy generally consists of solid solution treatment, intermediate treatment and aging treatment. The core of deformation of superalloy is the process plasticity and critical deformation coarse crystal.
Superalloy heating is divided into two stages: preheating and heating. In order to shorten the heat preservation time of the superalloy at the forging heating temperature, avoid excessive grain coarsening and alloy element dilution, and at the same time, in order to reduce the thermal stress caused by the poor thermal conductivity and large thermal expansion coefficient of the superalloy, the blank should be preheated before forging on the forging press.
The heating equipment can choose a resistance furnace, with a thermometer and automatic temperature control device, so as to accurately control. In order to avoid the dilution of chromium, aluminum, titanium and other elements on the surface of the blank, the fatigue strength of the alloy and the high temperature endurance strength should be reduced. Before forging blank heating, it is necessary to clean and remove dirt to avoid surface defects caused by corrosion.
Due to the influence of improper forging parameters and friction in forging process of the forging press, the deformation in the forging process is uneven. In order to control the grain size of the cake or plate, the heating temperature of the forging press should be controlled first.
The selection of forging and subsequent heat treatment process parameters directly affects the mechanical properties of forgings.