La découpe de l’acier par laser CO₂. Étude de la zone affectée thermiquement

CO₂ laser cutting of steel: heat affected zone investigation

¹ LABOMAP- E.N.S.A.M- CER de Cluny, France
² GEMPPM- CALFETMAT, INSA de Lyon, Villeurbanne cedex, France

Abstract

The growth of laser cutting industry is well known, especially for steels. By using oxygen as assisting gas, a high cutting rate is achievable. If a lot of works have been reported on the process itself and on its efficiency, little attention has been focused on metallurgical transformation induced in the heat affected zone (HAZ) in the steel sheets, while these effects are of major importance for the further use of the laser cutted workpieces.

The present paper reports results concerning the investigation of working parameters influence on HAZ geometry near the cut edges induced by heat flow during laser cutting. Materials investigated were mild steel (E24) and medium carbon steel (XC42). Beam power, oxygen pressure, thickness of the sample and travel speed of the workpiece were varied. The configuration of the HAZ geometry and microstructure observed were explained. This experimental program indicates that there is a strong effect of the experimental parameters on the HAZ geometry. Both geometrical and hardness measurements are reported.