| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a steel plate of a boron steel which has excellent workability, and also, can obtain high quench hardness at the surface layer part in carburizing and quenching at a low carbon potential. <P>SOLUTION: The carburizing steel plate having excellent workability has a composition comprising, by mass, 0.10 to 0.50% C, ≤0.50% Si, 0.20 to 1.8% Mn, 0.20 to 2.0% Cr, ≤0.02% P, ≤0.02% S, 0.01 to 0.20% Ti, 0.002 to 0.10% Al and 0.0005 to 0.0050% B, and the balance Fe with inevitable impurities, and in which carbonized materials are dispersed into ferrite, the average distance between the carbonized materials is ≥0.8 μm, X value defined by formula (1) is ≤40, Y value defined by formula (2) is ≥30, and also, hardness is ≤150 HV: X=30C+30Si+20Mn+5Cr+150S+80Ti-1.5 average distance between the carbides (1), and Y=5C+22Mn+32Cr (2). <P>COPYRIGHT: (C)2012,JPO&INPIT |
