Process for austempering ductile iron
US5753055A · kind A · utility
7Cited by
2References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 5, 1996 |
| Grant date | May 19, 1998 |
| Priority date | — |
| Expiry date | Nov 5, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D1/60
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for austempering ductile iron includes austenitizing a ductile iron casting of low alloy content followed by quenching the workpiece for a controlled period of time in a quench medium such as water, an aqueous polymer solution or a medium speed quench oil. The workpiece is then austempered in an air tempering furnace, resulting in a ausferrite microstructure essentially free of pearlite and martensite, and with mechanical properties meeting ASTM designation A897-90 "Standard Specification for Austempered Ductile Iron Castings." The process eliminates the need for a molten salt bath for quenching and tempering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.