Corrosion Behavior of High Nitrogen Nickel-Free Fe-16Cr-Mn-Mo-N Stainless Steels

Facile Synthesis of Metal Doped Graphite Carbon Nitride for Photocatalytic Degradation of Tetracycline Under Visible Light Irradiation

“…Three main peaks could be perceived from the high-resolution N 1s spectra (Fig. 4d), and the peak at 398.8 eV originated from sp 2 -bonded N atoms in triazine units (C = N-C) (Li et al 2009b, Takanabe et al 2010, and peak at 401.1 eV corresponded to amino groups (C-N-H) from the surface uncondensed bridging N atom (Liu et al 2010, which were similar to previously published literature (Chao et al 2014, Matanović et al 2015. The peak at 404 eV was assigned to the effects of surface charging or positive charge localization in the heterocycles (Kong et al 2018), or the π-π* excitations between the stacking interlayers (Li et al 2018).…”

Enhancing General Corrosion Resistance of Biomedical High Nitrogen Nickel-Free Stainless Steel by Nitric Acid Passivation

“…Figure 5 presents that CrN is the only form of N existed in both passive film and matrix of HNS. Hence, the distribution of the CrN in HNS is consistent with N. Many researchers also found the same results involving the existence of N in passive film of stainless steels by using XPS and secondary ion mass spectroscopy (SIMS) and demonstrated that CrN was short-range ordered amorphous [6,7,16,17]. At Cr c, d, N e, f present, a number of investigations have been performed with regard to the active dissolution behavior of N-alloyed stainless steel [18,19].…”

“…The study shows that the increase in N content could greatly enhance the resistance of metal dissolution [18]. A possible interpretation is that N is thermodynamically more stable than Fe and its dissolution reaction is a slow multi-electron process [17]. Besides, some researches show that the highly covalent character of the Cr-N bonding could cause an increase in the activation energy for the dissolution of matrix [20].…”

Corrosion behaviour of low temperature nitrided nickel-free, AISI 200 and AISI 300 series austenitic stainless steels in NaCl solution

“…Beyond the beneficial effect of nitrogen, the high corrosion resistance observed for nitrided AISI 316L and P558 also at high anodic potentials may be ascribed to the presence of Mo in these steels. Mo is able to enhance pitting corrosion resistance, and it is supposed to have effect in both delaying the attack of Clions on the passive film and improving repassivation [64][65][66]. By means of a synergistic action, Mo and N are able to improve corrosion resistance to localized phenomena (pitting, crevice) in chloride-ion containing solutions further on, when media with acidic or neutral conditions are present, as observed by other authors [10,25,66].…”

“…The potential value, corresponding to the current increase for the peaks detected in the present research, is about +630 mV (Ag/AgCl). On the basis of the Pourbaix diagram for a Cr-Mn-Mo steel [65], for an acidic solution, as the one expected for pitting or crevice phenomena, the oxidation of Cr 3+ , in form of Cr2O3, to Cr 6+ , as soluble Cr2O7 2-, might be supposed. At this potential value also the transformation of MoO3 into soluble MoO4 2might occur, but the fact that the anodic peak is observed also for stainless steels, which do not contain Mo, as AISI 202 [29,33], AISI 304L [29], and the 22Cr-18Mn-0.83N stainless steel [67], suggests that Cr oxidation plays the major role.…”