First-principles study of chromium diffusion in the ferritic Fe-Cr alloy

The post‐annealing effect on tribological and corrosion behaviors of CrN/AlCrN multilayered coating applied by CAE‐PVD

“…The diffusion distance by the Cr atoms into the substrate is approximately 1000 nm, and the annealing process is performed in 1 h. The diffusion coefficient ( D ) is calculated by the following equation 37 : $$$$\begin{equation}D\ = \frac{{{x}^2}}{{2t}}\end{equation}$$$$where x is the diffusion distance, and t is the process time. The Cr diffusion coefficient into the steel substrate at 600°C is 2.8 × 10 −16 m 2 /s, which is consistent with another study 38 . The interdiffusion between the alternating CrN and AlCrN layers can be seen in Figure 2B.…”

“…The Cr diffusion coefficient into the steel substrate at 600 • C is 2.8 × 10 −16 m 2 /s, which is consistent with another study. 38 The interdiffusion between the alternating CrN and AlCrN layers can be seen in Figure 2B. As shown in another study, 39 multilayered coatings begin to pinch off due to annealing heat treatment at specific temperatures and decompose completely over time.…”

“…Furthermore, when the annealing process temperature raises, the standard deviation corresponding to the parameters R a and R z increases, indicating irregular oxidation product formation on the surface. A Vickers microhardness test with a 25 g force was used to assess the coatings’ hardness, and the substrate effect was removed using the Jonsson–Hogmark method 38,42 . This method involves calculating the thin hard coating's hardness according to the following equation: $$$$\begin{equation}\ {H}_{\rm{f}} = {H}_{\rm{s}}\ + \frac{{{H}_{\rm{c}} + {H}_{\rm{s}}}}{{2C\ \left( {\frac{t}{d}} \right) + {C}^2\ {{\left( {\frac{t}{d}} \right)}}^2}}\end{equation}$$$$where H s , H f , and H c are the substrate hardness, coating hardness, and the combined hardness of the substrate and the coating, respectively, obtained from the Vickers microhardness test.…”

Molecular dynamics simulations of the initial oxidation process on ferritic Fe–Cr alloy surfaces

“…The metal substrate is a Fe–Cr alloy model with a pure Fe (100) surface which is established based on the previous relevant models. 26–28 For such metal substrate, the Fe atoms in each layer are randomly replaced 10 000 times by the Cr atoms according to the element content of Crofer 22 APU 25 and related work. 29,30 Then each substituted model is optimized and the probability distribution of energies of 10 000 models is found to obey the normal distribution.…”

Research on the Lattice Matching of Different Solute Atoms in BCC Fe: A Molecular Dynamics Simulation

“…The above simulation results are the same as those obtained by other different simulation methods and experiments. [34][35][36] By this token, in these high solution energy configurations, the atomic structure is hard to form, the solution energy of metal solute atoms is lower in the substitution configuration, and higher energy is required in the interstitial structure, while C atoms are prone to stay in the octahedral site.…”