High-strength, cold-forged type 316L stainless steel for orthopedic implant
US4718908A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1984 |
| Grant date | Jan 12, 1988 |
| Priority date | — |
| Expiry date | Jun 4, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S72/70
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A surgical implant manufactured from austenitic stainless steel by cold-forging has improved mechanical properties and corrosion fatigue resistance. The grain-size index for the cold-forged 316L stainless steel is increased from an ASTM grain-size index of about 8 to an ASTM grain-size index of about 14 by cold-forging the steel into the desired shape. Further improvement in mechanical properties and corrosion fatigue resistance is obtained by stress relieving the material after cold-forging into the desired configuration. The microstructure of the cold-forged material is characterized by the absence of visible slip planes at 600.times. magnification, in contrast with visible slip planes present in the microstructure of the austenitic stainless steel starting material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.