| 摘要 |
PURPOSE:To obtain a gear shaft fork with enhanced initial fitness, enhanced wear resistance and high machinability by adding a very small amount of B to nodular graphite cast iron, casting this material into the predetermined shape, and subjecting the sliding face to gas soft-nitriding. CONSTITUTION:To a composition of ordinary nodular graphite cast iron is added 0.005-0.03wt% B, and this material is cast into the predetermined shape of a gear shaft for a car, etc. At least a surface sliding along a sleeve is then subjected to gas soft-nitriding to form an Fe-N compound layer having >= about 8mum thickness. Thus, a gear shaft fork with enhanced initial fitness, superior wear resistance and superior endurance is obtd. with high dimensional accuracy. |
