Selective case hardening processes at low temperature
US6165597A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1998 |
| Grant date | Dec 26, 2000 |
| Priority date | — |
| Expiry date | Aug 12, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24942
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A selectively case hardened steel article by low temperature carburization includes a body made of a chromium bearing nickel or ferrous based alloy (for example, stainless steel), a first portion of the body having a first hardness characteristic, and a second portion of the body having a second hardness characteristic; the second portion being less than the entire body and substantially free of carbides. One method for selective case hardening by low temperature carburization includes the steps of applying a carbon blocking mask over surface areas of the article that are not going to be carburized; activating those surface areas that are to be carburized; diffusing carbon into the activated surface areas at a temperature below which carbides readily form; and removing the carbon blocking mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.