Nickel-based high-temperature alloy denitrification method

Abstract

The invention discloses a nickel-based high-temperature alloy denitrification method. The method comprises the following steps that smelting raw materials are carefully selected, an Inconel690 alloy ingot is smelted by adopting a ZG-0.025 type vacuum induction smelting furnace according to the following technological parameters that vacuumizing is performed to reach 0.01Pa, 10-15kW is kept for 10-20min, and 20-25kW is kept until the ingot is molten; the vacuum degree is less than or equal to 0.05Pa, refining is performed for 10min, and electromagnetic stirring is performed; under vacuum, the power is reduced for freezing and deflating, heating is performed again, and repeating for 2-3 times is performed; high-purity argon is introduced in high vacuum, the temperature is adjusted, deoxidizing elements, namely silicon and aluminum and a volatile element, namely manganese are added, microalloying elements, namely niobium, titanium and molybdenum are added after electromagnetic stirring, and electromagnetic stirring is performed; and the power is reduced, pouring is performed, cooling is performed, an ingot is taken out, and a riser is cut off. According to the method, the technological process is easy to achieve, safety, stability and reliability are achieved, and the nitrogen content of the ingot capable of being obtained is less than or equal to 10ppm.

Description

technical field [0001] The invention relates to the technical field of denitrification of nickel-based superalloys, in particular to a denitrification method of high-vacuum induction melting + prefabricated calcium oxide crucible + high-purity metal chromium. Background technique [0002] Because of their excellent corrosion resistance and high temperature oxidation resistance, nickel-based alloys are often used in equipment with harsh operating conditions and high safety requirements. With the continuous and rapid development of my country's economy, the equipment manufacturing industry has become a pillar industry of the national economy. The outstanding characteristics of the development of the equipment manufacturing industry are: the parameters of single-machine equipment are getting higher and higher, the conditions of use are becoming more and more stringent, and the requirements for safety are getting higher and higher. come higher. Welding is a key manufacturing pro...

AI Technical Summary

Problems solved by technology

Therefore, it is easy to develop cracks around the nitride, and these cracks will lead to the fracture of the metal

Nitrogen in the alloy can reduce the number of strengthening phases formed, thereby reducing the room temperature or high temperature strength of the metal

Especially in nickel-based superalloys containing aluminum and titanium, the main strengthening phase is Ni 3 Al or Ni 3 Ti, nitrogen in the alloy will make a part of aluminum and titanium form aluminum nitride and titanium nitride, thereby reducing the number of strengthening phases, increasing the number of inclusions, and finally leading to a decrease in the thermal strength of the metal