Descaling metal with a laser having a very short pulse width and high average power
US5736709A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 12, 1996 |
| Grant date | Apr 7, 1998 |
| Priority date | — |
| Expiry date | Aug 12, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/04
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The invention relates to an apparatus for using laser radiation to remove an oxide layer (scale) by vaporization from a hot rolled or annealed steel strip (40) traveling in a gravitationally vertical direction at a speed of at least 10 m/min. The apparatus includes a high power laser such as a free electron laser and a sealed interaction chamber (90) containing a non-oxidizing gas (108). The electromagnetic radiation from the laser has a surface power density of at least about 5 MW/cm.sup.2 at a point of contact with the metal strip surface. The radiation is passed through an optical system of aligned lenses or mirrors for focusing the radiation into a straight line projected transversely completely across the strip. The radiation has a pulse width less than 100 picoseconds, a pulse repetition rate greater than 10 MHz and a high average power of at least 10 kW. A radiation beam (56) is passed through a homogenizer (60) having a linear diverging lens (74) for spreading the radiation in a linear transverse direction. The radiation is passed through a cylindrical convergent lens (78) or a long cylindrical mirror (132) and focused into a straight line beam (36) projected completely acr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.