Chromium Carbides in Abrasion-Resistant Coatings

Effect of heat treatment on microstructure and properties of powder immersion reaction assisted chromium carbide coatings prepared on Q235 steel

“…However, significantly less carbon was required for the reaction between Cr 23 C 6 and carbon to form Cr 7 C 3 than the reaction to form Cr 3 C 2 . The outward diffusion of carbon obeys Arrhenius law, 25 𝐷 = 𝐷 0 × 𝑒 ( 𝐸 𝑎 𝑅𝑇 ) (5) where D is the diffusion coefficient at temperature T, D 0 is the diffusion coefficient at the reference temperature, R is the universal gas constant, T is the temperature (in Kelvin), and E a is the activation energy. The higher the heat treatment temperature, the greater the carbon diffusion coefficient.…”

“…Stable chromium carbides, such as Cr 3 C 2 , Cr 7 C 3 , and Cr 23 C 6, have received considerable attention for coating applications because of their high hardness, excellent chemical stability, and great corrosion resistance, especially for equivalent thermal expansion coefficient to steel. [1][2][3][4][5] In comparison to the vapor deposition method, [6][7][8][9][10] the spray method 3,4,11 and the laser cladding method, 12,13 diffusion-based methods, such as molten salt bath 1,2 and solid-state pack cementation 5,14 are simpler and easier; however, they are effective to prepare coatings on complex-shaped components. Powder immersion reaction assisted coating (PIRAC) method is an environmentally friendly solid-state pack cementation method, and it is free from the drawbacks of the salt bath immersion method, such as high-temperature salt-induced erosion, inhomogeneous and coarse surface, and so forth.…”

“…Stable chromium carbides, such as Cr 3 C 2 , Cr 7 C 3 , and Cr 23 C 6, have received considerable attention for coating applications because of their high hardness, excellent chemical stability, and great corrosion resistance, especially for equivalent thermal expansion coefficient to steel 1–5 . In comparison to the vapor deposition method, 6–10 the spray method 3,4,11 and the laser cladding method, 12,13 diffusion‐based methods, such as molten salt bath 1,2 and solid‐state pack cementation 5,14 are simpler and easier; however, they are effective to prepare coatings on complex‐shaped components.…”