HOT ROLLED STEEL SUITABLE FOR POST HEAT TREATABLE COMPLEX SHAPED PARTS WITH EXCELLENT HOLD EXPANSION RATIO AND EXCELLENT YIELD RATIO PARTS AND MENUFACTURING FOR THE SAME

摘要

A hot-rolled annealed steel sheet having excellent cold formability, a member, and a method for manufacturing the same are provided. The hot-rolled annealed steel sheet of the present invention, by weight%, C: 0.3 to 0.5%, Mn: 0.7 to 1.4%, Si: 0.4% or less, P: 0.03% or less, S: 0.01% or less, Al: 0.05% or less, Cr: 0.3% or less, Mo: 0.3% or less, Ni: 0.3% or less, Cu: 0.3% or less, Ti: 0.05% or less, B: 0.005% or less, N: including less than 0.008%, Relation 1-3 It is satisfactory, and contains ferrite and cementite as a microstructure.