| 摘要 |
PROBLEM TO BE SOLVED: To produce non-refining steel for hot forging with a ferritic-pearlitic structure excellent in wear resistance by optimizing the elements to be added for strengthening (solid solution-strengthening) ferrite by allowing Si and Mn to enter into solid solution in ferrite and moreover limiting the number of relatively large oxide inclusions. SOLUTION: This steel contains 0.3 to 0.8% C, 0.3 to 2.0% Mn and 0.5 to 2.5% Si, F value prescribed by the formula: F=[Si]+[Mn]/3.5 [In the formula, [Si] and [Mn] denote the content (mass %) of each element] is >=1.0, and the number of oxide inclusions of >=20μm average grain size per 300 mm2 of the area to be inspected is <=10 pieces.
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