SEM structure and properties of ASP2060 steel after laser melting

The paper presents laser melting technique that use the laser beam in order to change the surface layer properties. Metallographical (SEM), X-ray energy dispersive spectroscopy, X-ray diffraction, sliding wear resistance as well as microhardness investigations are presented as an illustration showing the benefits of laser application in modification of ASP2060 high-speed tool steel surface layer properties. The high chemical homogeneity and fine structure of the melted zone were attributed to high cooling rates due to the short interaction time with the Nd:YAG pulsed laser radiation and relatively small volume of the melted material. An increase in microhardness of the laser-melted zone after tempering may be probably attributed to fine precipitates formed in melted zone and to the transformation of the retained austenite. Samples treated by a pulsed laser radiation showed better wear resistance than the conventionally heat-treated ones.