Formation, evolution and remove behavior of manganese-containing inclusions in medium/high manganese steels

Self Cite

The present work assesses the effect of alloying element of Mn, Al, C, and Si on formation and evolution behaviour of manganese‐containing inclusions in medium/high‐manganese steel. The results indicate that the manganese‐containing inclusions after Al addition were gradually transformed from MnO‐MnS into MnS, MnS‐Al2O3 and MnS‐Al2O3‐AlN‐TiN with large size of about 10 μm. Besides, as the Mn content increases, the main manganese‐containing inclusions are polyhedral MnS‐Al2O3 and MnS‐AlN with sharp edge, and the proportion of AlN and TiN in complex inclusions increases. Additionally, the increase of Mn content significantly reduces liquid phase temperature and extension of the solid‐liquid two phase zone, promoting the divorced eutectic transformation of type II to type III of MnS, lead to the polyhedral MnS preferentially precipitation at early stage of solidification process. Furthermore, it also observed that the main manganese‐containing inclusions were irregular MnS and MnS‐AlN with edge and larger sizes of 10–50μm in the case of manganese steel grades with high C or Si content, which is attributed to divorced eutectic transformation and increase of activity of S and Mn. Moreover, the C element possesses most obvious promoting effect on the precipitation of MnS, followed by Si and Mn elements.

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

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

Liu,

Chu,

Liu

et al. 2023

Self Cite

“…The lattice parameters of different inclusions are shown in Table 6 , [ 5,48–50 ] and the calculation results of mismatch degree at the interfaces of different inclusions are shown in Figure 11 . From Figure 11, the mismatch degrees of Al 2 O 3 /MnS, AlN/MnS, TiN/MnS, and AlN/Al 2 O 3 are 8.41%, 8.94%, 11.65%, and 11.66%, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…In the equation, the low-index lattice planes of the substrate and nucleation phase are represented by (hkl) s and (hkl) n . The low-index crystal orientation in (hkl) s and (hkl) n is represented by [uvw] The lattice parameters of different inclusions are shown in Table 6, [5,[48][49][50] and the calculation results of mismatch degree at the interfaces of different inclusions are shown in Figure 11. From Figure 11, the mismatch degrees of Al 2 O 3 /MnS, AlN/MnS, TiN/MnS, and AlN/Al 2 O 3 are 8.41%, 8.94%, 11.65%, and 11.66%, respectively.…”

Section: Precipitation Mechanism Of Complex Inclusionmentioning

confidence: 99%

“…

In recent years, Fe-Mn-Al-C low-density steel has been applied in important fields such as automobiles, ships, and aerospace, due to its excellent wear resistance, corrosion resistance, and lightweight. [1][2][3][4][5] Mn element has the effect of expanding the austenite zone, and its induced twinning effect is beneficial for hindering the propagation of cracks in the material, significantly improving the plasticity of the steel. [6] When the Al content in the steel increases by 1%, the density of the steel decreases by about 1.3%.

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mentioning

confidence: 99%

See 1 more Smart Citation

Effect of Al Content on Inclusions in Fe‐15Mn‐xAl‐C Low‐Density Steel

Cao,

Wang,

Xiao

et al. 2024

Three experiments of Fe‐15Mn‐xAl‐C (x = 1, 3, 5) low‐density steel with different Al contents are carried out, and the characteristics of inclusions are observed through field‐emission scanning electron microscopy. The results show that the types of inclusions in the three samples are almost the same, mainly Al2O3, AlN, MnS, TiN, Al2O3‐MnS, AlN‐MnS, TiN‐MnS, and Al2O3‐AlN‐MnS. The number percentage of Al2O3 decreases, while the number percentage of AlN increases with the increase of Al content in the three samples. As the Al content increases, the number of inclusions between 1 and 5 μm decreases, while the number between 5 and 10 μm increases. FactSage8.2 software calculation shows that an increase in Al content leads to an increase in the liquidus and a decrease in the solidus of the steel; at the same time, it causes the austenite region to narrow and expands the ferrite region. The change in the solidification route leads to a delay in the solidification fraction of AlN, MnS, and TiN inclusions precipitation. At last, the 2D mismatch theory shows that the mismatch degrees of Al2O3/MnS, AlN/MnS, TiN/MnS, and AlN/Al2O3 are 8.41%, 8.94%, 11.65%, and 11.66%, respectively.

Effects of Typical Inclusions on the As‐Cast Microstructure and Recrystallization of Low‐Density Steel

Guo,

Zhu,

Wang

et al. 2024

Herein, the effect of nonmetallic inclusions (NMIs) on the microstructure and dynamic recrystallization (DRX) of Fe–23Mn–6Al–0.7C low‐density steel is studied. The specimens are separately added sulfur (S) and nitrogen (N) to change the characteristics of NMIs. As a result, the addition of S significantly increases the number of MnS inclusions and AlN–MnS complex inclusions in low‐density steel. The addition of N results in a significant increase in the size of NMIs. In the results, NMIs act as the heterogeneous nucleation sites for austenite and refine the as‐cast grains in low‐density steel. In addition, the treated specimens are subjected to a thermal compression simulation experiment. During the thermal compression process, discontinuous DRX is considered to be the main recrystallization method in the experimental low‐density steels. Meanwhile, the typical NMIs significantly accelerate the DRX within grains in low‐density steel through the mechanism of particle‐stimulated nucleation and continuous DRX.