STRUCTURAL STEEL MATERIAL AND METHOD FOR MANUFACTURING SAME

A structural steel material according to an aspect of the present invention contains, in weight percent, 0.12-0.18% of C, 0.02-0.5% of Si, 0.6-1.6% of Mn, 0.002-0.06% of Sol. Al, 0.001-0.05% of Nb, 0.001-0.06% of V, 0.003-0.009% of Ti, 0.0002-0.006% of Ca, 0.0002-0.0005% of B, 0.001-0.006% of N, 0.02% or less of P, and 0.003% or less of S, with the remainder comprising Fe and inevitable impurities, and satisfies relational expression 1 below. The microstructure of the structural steel material includes a composite structure in which ferrite is the main phase and pearlite is the second phase, with the remainder comprising a hard structure, wherein the average grain size of the ferrite may be 20 µm or less. [Relational expression 1] [N] - 0.3*[Ti] - 0.1*[Nb] ≤ 0.001(wt%), where [N], [Ti], and [Nb] represent the contents (wt%) of N, Ti, and Nb in the steel material, respectively.