Process for providing valve members having varied microstructure
US4741080A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1987 |
| Grant date | May 3, 1988 |
| Priority date | — |
| Expiry date | Feb 20, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49306
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for providing an engine valve (2) with varied microstructure grain size is provided. The process includes the steps of: providing a slug (4) of suitable metallic valve composition having a grain size of less than about A.S.T.M. 8; solution heat treating slug (4) to provide a larger grain size and to substantially dissolve carbonitride stringers if present; and forging the solution heat treated slug (4) in a manner that provides a substantially uniformly distributed A.S.T.M. grain size of about 1 to about 7 in a central region beneath the combustion face of head (14) of valve (2) while cold working a seat face (16) on head (14) and extruding the stem (10) of valve (2) such that its microstructure grain size is less than about A.S.T.M. 8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.