Microstructural and Hardness Investigation of Tool Steel D2 Processed by Laser Surface Melting and Alloying


Several techniques can be used to improve surface properties of metals. These can involve changes on the surface chemical composition such as alloying or on the surface microstructure, such as hardening. In the present work, melting of the surface by a 9 kW CO2 CW laser of wavelength 10.6 μm was used to alter surface features of D2 tool steel. Carbon powder and nitrogen gas were used as sources of alloying elements during laser processing. The effect of various laser parameters (power and speed) on the microstructure and hardness of D2 tool steel was investigated. Laser powers from 1 to 8 kW and laser speeds from 5 to 15 mm/s were employed. It was found that as the laser power increases, the hardness of the melted zone decreases while that of the heat-affected zone increases. On the other hand, the depth of both of melted and heat-affected zones increases with power.


Materials Science and Engineering

Second Department

Mechanical and Aerospace Engineering

Keywords and Phrases

Alloying; Carbon Dioxide; Continuous Wave Lasers; Corrosion; Hardness; Heat Affected Zone; Laser Optics; Melting; Microstructure; Tool Steel; Laser Parameters; Laser Surface Alloying; Laser Surface Melting; Laser Surface Treatment; Micro-Structural; Surface Chemical Composition; Surface Feature; Surface Microstructures; Alloying Elements; Material Heat Treatment

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2014 Springer Verlag, All rights reserved.

Publication Date

01 Aug 2014