Hot-rolled steel and steel parts for steel parts with excellent fit and machinability between fracture surfaces after fracture separation

摘要

PROBLEM TO BE SOLVED: To provide a steel material by reducing fracture surface neighbor deformation volume during fracture separation, increasing irregularity of a fracture surface and enhancing fittability, and suppressing lack of the fracture surface.SOLUTION: There is adopted a hot rolled steel material for steel component, excellent in fittability and machinability of fracture surfaces each other after fracture separation, containing C:0.35-0.45 mass%, Si:0.6-1.0 mass%, Mn:0.60-0.90 mass%, P:0.010-0.035 mass%, S:0.06-0.10 mass%, Cr:0.25 mass% or less, V:0.20-0.40 mass%, Zr:0.0050 mass% or less, N:0.0060-0.0150 mass%, and further one or more kinds selected from a group consisting of Sb:0.0001-0.0050 mass% and Sn:0.0001-0.0050 mass%.SELECTED DRAWING: None