Mechanistic approach of Goss abnormal grain growth in electrical steel: Theory and argument

Abstract

The first Si-Fe electrical steel was produced in 1905, and the grain-oriented steel was discovered in 1930 after Goss demonstrated how optimal combinations of heat treatment and cold rolling could produce a texture giving Si-Fe strip good magnetic properties when magnetised along its rolling direction. This technology has reduced the power loss in transformers greatly and remains the basis of the manufacturing process today. Since then many postulations reported on the mechanism on abnormal grain growth (AGG) which is the key for Si-Fe superior magnetic properties, however, none have provided a concrete understanding of this phenomenon. Here, we established and demonstrated a new theory that underlines the fundamental mechanistic approach of abnormal grain growth in 3% Si-Fe steel. It is demonstrated, that the external heat flux direction applied during annealing and Si atom positions in the solid solution disordered a-Fe cube unit cell that cause lattice distortions and BCC symmetry reduction are the most influential *Manuscript Click here to download Manuscript: Manuscript.pdf Click here to view linked References factors in the early stage of Goss AGG than what was previously thought to be dislocation related stored energy, grain boundary characteristics and grain size/orientation advantages.

Complete Goss Secondary Recrystallization by Control of the Grain Size and Texture of Primary Recrystallization in Grain-Oriented Silicon Steel

“…The behavior of Goss AGG has strong correlations with the matrix of primary recrystallization in grain-oriented silicon steel. Microstructure [4][5][6], texture [7][8][9], and inhibitors [10,11] in the matrix all play important roles in this process. The homogeneous primary recrystallization microstructure under the restriction of inhibitors is beneficial to maintain the stability of matrix during high-temperature annealing [11][12][13].…”

The Effects of Deformation Conditions and Microstructural Features on Typical Textures of a Non-oriented Electrical Steel in Electrically Assisted Forming

“…Microstructural features such as grain size, grain boundaries, and microstructural defects were found to have close relationships with typical textures in many studies. [25][26][27][28][29][30][31][32] The rotated cube is difficult to be obtained in a traditional recrystallization process, since it shows a lower stored energy during a conventional cold rolling than the other orientations. [25] In the research of Goss texture, many research works focused on the relationship of Goss grain features and Goss textures.…”

“…[25] In the research of Goss texture, many research works focused on the relationship of Goss grain features and Goss textures. [26][27][28][29][30][31][32] Large grain size brought stronger Goss texture as abnormally growing grains of Goss are often found during steel processing. [26][27][28] Higher fractions of coincident site lattice (CSL) grain boundaries are related to Goss texture, especially R3 and R9 grain boundaries.…”

Joining of the Laminated Electrical Steels in Motor Manufacturing: A Review

“…As a machine to transform the electrical energy into mechanical energy, a motor has been widely used as the traction machine in industry equipment [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ], e.g., electrical vehicle, electrical airplane, electric ship, and so on. Electrical steel [ 8 , 9 , 10 , 11 ], a high silicon (2–5.5 wt% Si) [ 12 , 13 ] and thin sheet (0.2–0.65 mm) steel [ 14 ], is the soft magnetic material for the stator and rotor in a motor [ 15 , 16 , 17 ]. The addition of silicon to iron results in a decrease in coercivity and an increase in resistivity [ 12 , 18 , 19 , 20 , 21 , 22 ].…”