Research progress in abnormal grain growth mechanism of Goss grains in grain-oriented silicon steel

Grain-oriented silicon steel stands as the cornerstone soft-magnetic material for ultra-high voltage transformers and high-efficiency energy-saving distribution transformers. Its outstanding magnetic properties， characterized by high magnetic flux density and low core loss， are mainly ascribed to the well - defined Goss texture in the final microstructure. Nevertheless， the mechanism governing the abnormal grain growth （AGG） of Goss grains during annealing is exceedingly intricate and remains incompletely understood， posing a significant bottleneck that impedes the further enhancement of its magnetic performance.This review comprehensively summarizes the nucleation and growth behaviors of Goss grains throughout the entire manufacturing process， spanning from hot rolling to high-temperature annealing， and delineates the optimization strategies for key production processes. It also systematically synthesizes the typical features of abnormally grown Goss grains， such as grain size， orientation deviation， and internal island grains， with a particular emphasis on analyzing how these features influence magnetic properties and the corresponding regulatory approaches. Moreover， a thorough review is conducted on various theoretical models proposed for the AGG mechanism of Goss grains， covering their fundamental principles， applicability， and limitations. Finally， key research directions for future investigations into the Goss AGG mechanism are proposed， aiming to offer a valuable reference for promoting the development of high-performance grain-oriented silicon steel.