Steel for carburization skew bevel gear, high Characteristic carburization skew bevel gear and its production manner

摘要

PROBLEM TO BE SOLVED: To provide a steel for carburized bevel gear little in alloy components such as Ni, Mo, Si, in comparison with a case hardening steel used conventionally, reduced in the material cost and manufacturing cost and excellent in impact strength, and to manufacture a high toughness carburized bevel gear. ;SOLUTION: This steel material is composed of 0.15-0.25wt.% C, 0.30-0.90wt.% Mn, ≤0.10wt.% Si, 0.001-0.003wt.% B, 0.3-1.2wt.% Cr and/or 0.2-0.9wt.% Mo and the balance Fe with inevitable impurities. Further, (Mn+Cr+Mo)≤1.7wt.% is satisfied. After applying cold-forging to this steel material, the carburizing treatment is executed and further, hot-forging is applied. By this method, the bevel gear having ≥1.5 impact input torque ratio is obtd.;COPYRIGHT: (C)1997,JPO