炭素鋼線의 球狀化燒鈍에 미치는 加工度의 影響에 대한 硏究를 위하여 直徑 4㎜의 0.74%C 鋼線을 2.8, 2.0, 1.4 및 1.0㎜로 冷間伸線하여 640°∼730℃ 사이의 溫度에서 球狀化處理하였다.
球狀化된 cementite粒子의 크기는 顯微鏡寫眞에서 測定된 單位面積當粒子數로 부터 算出하였다. comentite粒子의 成長은 670℃ 以上에서 Lifshitz-Wagner의 擴散律速成長理論式에 一致되었다. 加工度의 影響은 有效擴散係數의 크기로서 考察하였으며 이때 球狀化를 爲한 活性化에너지는 約 40㎉/mole였다.
This work was undertaken to study the effect of degree of working applied during the drawing on spheroidization of cementite in 0.74%C steel wire. The effect of drawing was evaluated by the particle size of spheroidized cementite. Particle size of spheroidized cementite was calculated by Fullman method, replacing the number of particles per unit area counted in photomicrograph. Specimens of steel wire were prepared by cold drawing from 4.0㎜ to 2.8, 2.0, 1.4 and 1.0㎜ in diameter, and annealed at temperatures between 640° and 730℃ for various times up to 45 hours, From this experimental results, it was found that the spheroidization of cementite was controlled by diffusion, and also the effective diffusion coefficients were increased with increasing amount of cold work. The activation energy for the spheroidizing was found to be 40 ㎉/mole. The results may be rationalized by the theory proposed by Liishitz-Wagner.