| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel for machine structure with small heat treatment deformation, which is for power transmission parts of gears, shafts or the like of automobiles, industrial machines or the like. SOLUTION: The steel stock for machine structure with small heat treatment deformation is a steel stock comprising a steel for machine structure including, by mass, C: 0.15-0.35%, Si: 0.10-1.50%, Mn: 0.10-1.00%, P: at most 0.030%, S: at most 0.030%, Cr: 0.90-1.90%, Cu: at most 0.30%, Al: 0.008-0.800%, B:0.0003-0.0050%, O: at most 0.0030%, N: 0.0020-0.0100%, a remainder Fe, and inevitable impurities, wherein the Ms point is at most 460°C, the ratio value of the hardness J9 at the distance of 9 mm from the quenching end by Jominy end quenching method to the hardness J1.5 at the distance of 1.5 mm is 0.68-0.97, and the ratio value of the hardness J11 at the distance of 11 mm to the hardness J1.5 at the distance of 1.5 mm is 0.63-0.94. COPYRIGHT: (C)2013,JPO&INPIT |
