HOT-ROLLED STEEL BAR OR WIRE ROD FOR COLD FORGING

PROBLEM TO BE SOLVED: To provide a hot-rolled steel bar or wire rod excellent in cold forgeability and property preventing coarsening of γ grains.SOLUTION: The hot-rolled steel bar or wire rod has a chemical composition containing 0.1-0.3% C, 0.05-1.0% Si, 0.4-2.0% Mn, 0.003-0.05% S, 0.5-3.0% Cr, 0.010-0.025% N, 0.02-0.05% Al and the balance being Fe and impurities, wherein the impurities contain P≤0.025%, Ti≤0.003% and O≤0.002%, and has a metal structure composed of a ferrite/bainite structure or a ferrite/bainite/pearlite structure wherein the structural fraction of bainite is >70% and the average particle size of ferrite is ≤40 μm. In a region within 1/5 of a radius from a surface of the steel bar or wire rod and in a region within 1/5 of a radius from a center, the content of Al precipitated as AlN is ≤0.010%, and the piece density of AlN having a diameter of ≥100 nm is ≤5 pieces/100 μm.