Gaseous alloying with Laser Heating

Abstract

Laser heat treatment can be used to harden steel. By changing the surface composition the hardenability can be increased. The surface composition can be changed most simply by carrying out the Laser treatment in an appropriate atmosphere. This is demonstrated by variously treating two steels in argon, air, nitrogen, C02 and acetylene. Gaslegieren mittels LaseraufheizungStahle lassen sich durch eine Laser-Warmebehandlung harten. Eine Anderung der Oberflachenzusammensetzung bewirkt eine Erhohung der Hartbarkeit. Indem die Laserbehandlung in einer geeigneten Atmosphare durchgefiihrt wird, kann die Zusammensetzung wahrend des Hartevorgangs simultan verandert werden. Dies wird an zwei Stahlen in verschiedenen Atmospharen Argon, Luft, Stickstoff, C 0 2 und Acetylen gezeigt.

Laser surface hardening of bearing steels

“…The carburization inside the steel occurs either by surface alloying mechanism or by solid state diffusion [248]. The near surface region which melt due to laser heating permits more amount of carbon to be absorbed quickly by surface alloying mechanism [268,269]. As the carbon content in the steel increases, various phases appear on rapid solidification of the melted zone.…”