Hetero-epitaxial nucleation of ferrite at a TiN encapsulating MgAl2O4 during rapid solidification in a newly developed ferritic stainless steel

Kim, Jun Yeon; Oh, Nu Ri; Oh, Yong Hee; Cho, Young Tae; Lee, Won Bae; Kim, Sun Koo; Hocheng, H.

doi:10.1016/j.matchar.2017.09.001

Cited by 23 publications

(1 citation statement)

References 29 publications

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“…The black cores can be identified to be MgO or MgAl 2 O 4 , the grey part to be TiN. MgAl 2 O 4 was formed by interfacial reaction at the interface of TiN/MgO [19][20][21][22]. MgO or MgAl 2 O 4 increased the nucleation ratio of TiN at the beginning of solidification and inhibited the growth of TiN, as a result, the composite particles were formed at a relatively small size.…”

Section: The Characteristic and Composition Of Tin Inclusionsmentioning

confidence: 99%

Effect of Mg–Ti Treatment on Nucleation Mechanism of TiN Inclusions and Ferrite

Zhang

Wang

et al. 2020

Metals

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Large sizes of columnar crystals and TiN particles have a great influence on the surface quality of ferritic stainless steel. In the present paper, this study proposed to obtain fine-grained equiaxed structures by Mg–Ti treatment. Through the experiment happened in resistance furnace with argon protection, the refining effect of Mg–Ti addition on the microstructure and TiN particles were investigated, and the refinement mechanism was discussed from interface coherence theory. It was found that due to adding Mg and Ti into molten ferritic stainless steel, the equiaxed crystal ratio increased from 37% to 50%, and the size of TiN particles reduced at the same time. The lattice matching characteristics of MgAl2O4/TiN and TiN/δ-Fe were investigated by FIB-HRTEM. According to Bramfitt’s equation, the lattice misfit for (400)MgAl2O4∥(200)TiN and (200)TiN∥(110)δ-Fe was 5.02% and 4.41%, respectively, which were all belong to the effective nucleation range. It could be considered that MgO and MgAl2O4 formed in the molten steel promoted TiN nucleation easier to precipitate out with large quantities in the liquid phase. The TiN particles with more uniform distribution significantly enhanced the heterogenous nucleation of ferritic phase during initial solidification process base on the good lattice fitting condition. Finally the equiaxed crystal ratio of δ-Fe phase increased dramatically.

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Section: The Characteristic and Composition Of Tin Inclusionsmentioning

confidence: 99%