The role of each element of the nickel-based alloy tube

The main alloying elements of nickel alloy tubes are chromium, tungsten, molybdenum, cobalt, aluminum, titanium, boron, zirconium, etc., among which chromium and aluminum function and anti-oxidation, and the rest of the alloying elements act on solid solution strengthening, precipitation strengthening and grain boundary Strengthen etc. The material of the nickel-based alloy tube can have high strength and certain oxidation and corrosion resistance at a high temperature of 650-1000 ° C, and has high enough high temperature strength and oxidation and corrosion resistance, so it is often used to make aero-engine blades, rocket engines, and nuclear reactors , High-temperature components on energy conversion equipment, etc.

(1) Boron and silicon elements
   ①The presence of boron and silicon elements can significantly reduce the melting point of the alloy, expand the solid-liquidus temperature zone, and form a low-melting eutectic.
   ② It has the function of deoxidation reduction and slagging.
   ③ Hardening and strengthening of the coating.
   ④ Improve the performance of the operating process.
(2) Copper element
   The presence of copper element can improve the corrosion resistance of nickel-based alloy pipes to non-oxidizing acids.
(3) Chromium
   ①The presence of chromium makes the nickel-based alloy tube have solid solution strengthening and passivation.
   ② Improve corrosion resistance and high temperature oxidation resistance.
   ③Excess chromium is easy to form chromium carbide and chromium boride hard phase with carbon and boron elements to improve the hardness and wear resistance of the alloy.
(4) Molybdenum element
   ① The atomic radius is large, and the solid solution causes a large distortion of the crystal lattice, which significantly strengthens the alloy matrix and improves the high-temperature strength and red hardness of the matrix.
   ②It can cut and reduce the network structure in the coating.
   ③ Improve cavitation and erosion resistance.