| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high yield strength, high toughness non-heat treated hot-forged component, and a method for producing the same. <P>SOLUTION: The high yield strength, high toughness and non-heat treated hot-forged component has a composition comprising, by mass, 0.20 to 0.80% C, ≤0.50% Si, 0.40 to 1.00% Mn, ≤0.050% P, ≤0.050% S, 0.20 to 0.80% V, 0.02 to 0.30% Nb and ≤0.0100% N, and the balance Fe with inevitable impurities, and has a ferrite-pearlite structure where the Gf grain size number of old austenite grains is ≥6, and in which the number density of (V, Nb)C precipitates with a diameter of ≤10 nm in the ferrite and pearlite is ≥5,000 pieces/μm<SP POS="POST">2</SP>. <P>COPYRIGHT: (C)2012,JPO&INPIT |
