Back to DIS Home Page

Previous | Index | Next

Stage 2

Rapid transfer of the castings to the austempering furnace (usually a salt bath) where the castings are held isothermally at the selected austempering temperature. Austempering temperatures are in the range 450-750°F (230-400°C) according to the properties required in the castings (ADI grade). Close control over temperature and time of austempering is essential.

ADI is well established as a gear material replacing forged steel with major production cost savings, quieter operation, and reduced weight. By machining the gears before the austempering heat treatment, major savings in machining costs are achieved.


Courtesy: General Motors Corp, Central Foundry Div., Saginaw, Michigan, USA

Austempered Ductile Iron Hypoid Axle Gears: Conversion to Cast Ductile Iron from Forged Steel gave major production cost saving, better machinability, quieter operation, reduced weight.


ADI Timing Gears for Cummins B-Series diesel engines. Replaced forged and case carburised 1022 steel with 30% cost saving.

Page 13

Previous | Index | Next