Hot rolled bar stock, manufacturing method of parts and hot rolled bar stock

摘要

The present invention relates to a ferritic steel comprising 0.05 to 0.30% of C, 0.30 to 0.60% of Si, 0.40 to 1.0% of Mn, 0.008 to less than 0.040% of S, 1.60 to 2.00% of Cr, % Of N, 0.010 to 0.025% of N, 0.003% or less of Ti, 0.0001 to 0.0050% of Bi, and the balance of Fe and impurities. P and O in the impurities are 0.025% 0.002% or less, and the structure is made of ferrite, pearlite, ferrite, pearlite, bainite, and satisfies the formula (1). 1.70? Cr + 2 占 Mo? (One)