First-Principles Analysis of the Inhibitive Effect of Interstitial Carbon on an Active Dissolution of Martensitic Steel

Abstract The effect of interstitial carbon on the anodic dissolution rate of AISI 1045 martensitic carbon steel was investigated. The active dissolution current of high carbon martensite was lower than that of low carbon martensite, indicating that active dissolution was suppressed by interstitial carbon. First-principles calculations were performed to investigate the electronic structure of martensite. The electronic density of states near and at the Fermi level of bct Fe (martensite) decreased with increasing interstitial carbon. The number of valence electrons on the iron atom in the Fe-C system was lower than that in the pure Fe system.