Characterization of Oxidation Behavior of Mn Fumes Generated in the Vacuum Treatment of Melting Mn Steels

Abstract

Herein, the phase, composition, morphologies, particle size distribution, and specific surface area of Mn oxide fumes generated after the vacuum treatment of melting Mn steels with different initial Mn contents are characterized. The thermodynamic calculation results reveal that for a given temperature and pressure, Mn vapor generation increases with increasing initial Mn content in steel. Moreover, the experimental results find that the amount of the Mn oxide fumes on the vacuum chamber after vacuum processing gradually increases with increasing initial Mn content in the melt. The fumes on the crucible generated after vacuum processing are composed of mainly coral‐shaped Mn3O4 with the size of 500 nm and a small amount of spherical‐like Mn2O3 with the sizes of 50–200 nm. Meanwhile, the fumes deposited on the furnace chamber contain Mn nanoparticles with the sizes of less than 50 nm, MnO nanorods with the sizes of 50–200 nm, and Mn3O4 nanoparticles with the sizes of 50–500 nm. In addition, the main phase of the fumes deposited on the vacuum chamber gradually changes to elemental Mn with an increase in the initial Mn content. The temperature and particle size are responsible for thermodynamic stability of Mn oxides at the nanoscale.

Facile Electrodeposition of Mn-CoP Nanosheets on Ni Foam as High-Rate and Ultrastable Electrodes for Supercapacitors

“…The Mn 2p 3/2 contains two predominant peaks at 641.3 and 644.3 eV, which are due to Mn 2+ and Mn 4+ , respectively. 35,36 The peak as appeared at 647.4 eV is due to Mn−O, which might be caused by the oxidation of Mn in the air. 37,38 Two other peaks at 651.4 and 654.1 eV are ascribed to Mn 0 and Mn 3+ of Mn 2p 1/2 spectrum, respectively.…”

“…37,38 Two other peaks at 651.4 and 654.1 eV are ascribed to Mn 0 and Mn 3+ of Mn 2p 1/2 spectrum, respectively. 35 The Co 2p spectrum is presented in Figure 2c. In the Co 2p 3/2 region, two peaks assigned to Co 0 and Co 2+ can be observed at 778.2 and 781.4 eV, Scheme 1.…”

Microstructure-Based Fatigue Modeling with Residual Stresses: Effect of Inclusion Shape on Very High Cycle Fatigue Life

“…The value of ξ is calculated first with the data of circle inclusion (A = 1, (sinθ − h) × (A − 1) = 0). Therefore, for circle inclusion, Equation ( 16) becomes Equation (19).…”

“…As mentioned before, in addition to size, inclusions in steels have multiple features, including shape and mechanical/physical properties (Young's modulus, Poisson's ratio, thermal expansion coefficient, etc.). The mechanical properties of inclusions are governed by their compositions, which are connected to the generation process of inclusions [17][18][19][20]. The size and shape features belong to geometrical characteristics of inclusions.…”

The Effect of Alloying Elements on Formation and Evolution Mechanism of Manganese‐Containing Inclusions in Medium/High‐Manganese Steels

“…In contrast, the MnS is used as a typical manganese-containing inclusion in medium/high-manganese steel, in which the precipitation behavior is directly related to the control of overall inclusions. [31,32] Although the alloying elements in steel are considered to have a significant influence on MnS precipitation concentration product based on the divorce eutectic transformation and surface energy. Unfortunately, the effect of Mn, Al, C, and Si on the formation and evolution behavior of manganese-containing inclusions in medium/highmanganese steels are still not systematically revealed, especially with high alloy content.…”