Abstract: Focusing on the fluctuation problem of torsion property of steel wire after galvanizing in practice， microstructure evolution of the wire in the drawing， hot-galvanizing and torsion processes was systematically characterized and analyzed in this work. The results show that in the processes of drawing and torsion of the wire， the sorbite sheet is distorted， the lamellar spacing is reduced， the cementite sheet is broken， the small cementite particles are dissolved， and dislocation density greatly increases. The hot-galvanizing process can dissolve the small-sized cementite particles， eliminate the internal stress and reduce the dislocation density in the wire. The comprehensive effects of cementite sheet breakage， cementite particle dissolution， sorbite lamellar spacing and dislocation density lead to the performance difference in the process of steel wire torsion.

Key words: high carbon galvanized steel wire; microstructure; torsional property; cementite; sorbite; dislocation