Patent ID: 11180818

Abstract:
A steel bar for hot forging according to the present disclosure has a chemical composition consisting of, in mass percent, C: 0.05 to 0.40%, Si: 0.05 to 0.50%, Mn: 1.51 to 3.50%, P: 0.010 to 0.100%, S: 0.30% or less, Cr: 0.05 to 2.50%, V: 0.10 to 0.75%, Ti: 0.005% to 0.250%, Al: 0.005 to 0.060%, and N: 0.002 to 0.020%, with the balance being Fe and impurities, and satisfying Formula (1). A number density of TiNs having a circle equivalent diameter of not less than 20 μm in steel is 0.3 to 4.0/mm2: 0.48≤C+0.11Mn+0.08Cr+0.75V+0.20Mo≤1.50  (1) where, symbols of elements in Formula are to be substituted by contents of corresponding elements (in mass percent).