高炭素冷延鋼板の材料特性に及ぼす黒鉛,セメンタイトの影響

抄録

Either ferrite-cementite or ferrite-graphite mixed microstructure was developed after cold rolling and annealing in 0.65%C steels containing different amounts of Mn and Cr. These steels were again cold rolled and annealed in order to examine the effect of the kind of 2nd phase on the recrystallization process, texture development and the mechanical properties after annealing.
In the ferrite-cementite steel, recrystallization started at a lower temperature, but the ferrite grain growth was limited. The {111} and {100} textures formed by cold rolling were maintained even after the completion of the primary recrystallization and finally a sharp {111} <112> recrystallization texture was obtained. Whereas, in the ferrite-graphite steel, recrystallized grains grew markedly with large decreases of the {111} and {100} texture components, finally forming rather random texture after recrystallization. The difference in the recrystallization process was thought to be caused by differences in the volume fraction and the distribution of the second phase. The mean γ-value after full annealing was high in both steels, but the planer anisotropy of the γ-value was inverse. The high γ₄₅-value obtained in ferrite-cementite steel could be attributed to the strong {111}<112>plus {100}<011> texture.