| 摘要 |
<p>The invention relates to improvements in the induction hardening of crankshafts made from spheroidal graphite (SG) cast iron containing an orifice. At least one selected portion of the crankshaft is heated by induction heating from ambient temperature, at which the structure of the spheroidal graphite cast iron is pearlite, to a temperature at which the structure of the spheroidal graphite cast iron transforms to austenite. The crankshaft is subsequently cooled in a gaseous medium, such as air, to a temperature at which the structure of the spheroidal graphite cast iron transforms at least in part to martensite.</p> |
