Effect of Ferrite Grain Size on Local Elongation in a Low Carbon Steel

摘要

Effect of grain size on local elongation in low carbon steel was investigated. Ferrite-cementite (FC) steels with various ferrite grain sizes were prepared by using a low carbon steel and static tensile tests were performed at room temperature. The local elongation of the FC steels was almost the same regardless of the ferrite grain size, and the reduction in area decreased with decreasing grain size. The effect of ferrite grain size on local deformation for the FC steels was also investigated using the estimated true stress (σ)-true strain (ε) relationship up till just before fracture. In the estimated as relationships of the FC steels with various grain sizes, the true strain just before fracture was approximately 1.4 for grain sizes of more than 0.8 um, and a increased with decreasing grain size.