First-principles analysis of the inhibitive effect of interstitial carbon on an active dissolution of martensitic steel

Understanding the Efficacy of Concentrated Interstitial Carbon in Enhancing the Pitting Corrosion Resistance of Stainless Steel

“…As a result, both the electrical and thermal conductivities are decreased in the carburized alloy. 42 Additionally, XPS results on the carburized alloys, including both martensitic and austenitic steels, 8,43 show that the electron binding energy of Fe atoms for the sample with high interstitial carbon is higher than that of the sample without interstitial carbon, which can also be attributed to the formation of covalent M-C bonds.…”

Electrochemical Properties of Microstructures of Carbon Steels and Metallurgical Approaches for Improving Corrosion Resistance

“…には，電子伝導を担うフェルミ準位近傍の価電子が関与して いる (42) (44) ．Fe の価電子数が減少するということは，Fe の 電気化学反応を担う電子の数が減少するということであり， 反応速度定数が小さくなることに相当している (42) ．電荷密 度分布に加え，Fe の電子状態密度 (32) や仕事関数 (45) ルテンサイト試料でも SEM 観察が実施されており，MnS/ 母相境界部には溝が形成されているが，孔食発生には至らな かったことが確認されている (30) ．   靱性と耐食性を両立する焼戻し条件 上述の実験結果に基づき，靱性と耐孔食性を両立するため の熱処理の指針が提案されている (30) ．図は，図 4 および 図 5 の解析に用いた炭素鋼 S45C のマルテンサイト組織につ いて，874 K で焼戻した際のビッカース硬さと孔食電位を整 理したものである (30) ．孔食電位としては，MnS を含まない…”

Roles of Interstitial Nitrogen, Carbon, and Boron in Steel Corrosion: Generation of Oxyanions and Stabilization of Electronic Structure

“…6,7 The addition of interstitial elements have been widely investigated in the effort to achieve ultra-high strength steels used in corrosive atmospheric environments. [8][9][10][11] Despite the use of protective coatings of steel surfaces, corrosion can occur at the cut edges and at surface defects. Therefore, it remains important to elucidate the effects of N, C, and B on the corrosion resistance of steels for advances to be made in corrosion research.…”

“…23 Chiba et al reported that the work function of carbon steels was changed by the presence of 0.05-0.1 mass% interstitial N. 8 Also, the work function of Fe-33Mn steels was changed due to the presence of more than 0.29 mass% interstitial C. 9 Sun revealed that an expanded lattice parameter of carburized austenitic stainless steel changes the surface reactivity. 16 We previously applied first-principles calculations to clarify the effect of interstitial C on the electronic structure of bct Fe (martensite), 11 and it was revealed that the electronic density of states (DOS) of Fe at and near the Fermi level decreased by the C concentration. Because the valence electrons around the Fermi level are thought to affect the kinetics of electron (charge) transfer in redox reactions such as the active dissolution of steels, the decrease in the DOS of Fe at the Fermi level is a possible explanation for the corrosion inhibition effects of interstitial C. Both N and B are located in the periodic table close to C, so it is reasonable to assume that the electronic structures of Fe-N and Fe-B alloys are z E-mail: mariko.kadowaki.s4@dc.tohoku.ac.jp; aksaengdeejing@rift.mech.tohoku.…”

“…In our previous research, it was revealed that the electronic structure of Fe was changed by the presence of interstitial C, which might affect the anodic dissolution resistance. 11 Both N and B are located in the periodic table close to C, so it is reasonable to assume that interstitial N and B might also change the electronic structures of Fe. To elucidate the electronic structures of Fe with N, C, and B, first-principles calculations were performed.…”