Process for high quality plasma arc cutting of stainless steel and aluminum
US5414236A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1992 |
| Grant date | May 9, 1995 |
| Priority date | — |
| Expiry date | Dec 11, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/10
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A plasma arc torch uses a mix of reactive and reducing gas flows to cut sheets of stainless steel, aluminum and other non-ferrous metals. The reducing gas flow to the cut is varied as a percentage of the total gas flow to maintain a reducing atmosphere down through the cut, but to leave a predominantly oxidizing atmosphere at the intersection of the cut and the bottom surface of the sheet being out. These flows can also be characterized as either a plasma gas flow, one that forms the arc, or a shield gas flow that surrounds the arc. The reactive gas is preferably a flow of air, oxygen, nitrogen, carbon dioxide or a combination of these gases. The reactive gas is usually in the plasma gas flow, whether alone or mixed with other gases. The reducing gas is preferably hydrogen, hydrogen 35, methane, or a mixture of these gases. For aluminum, the reactive gas is preferably air or nitrogen and the reducing gas is preferably methane or a mixture of methane and air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.