Surface condition, microstructure and microhardness of boronized layers produced on Vanadis-6 steel after modification by diode laser

Abstract

A B S T R A C TThe paper presents the study results of surface condition, microstructure and microhardness of Vanadis-6 tool steel after diffusion boriding and laser modification by diode laser. As a result of diffusion boriding the layers consisted of two phases: FeB and Fe2B. A bright area under the continuous boronized layers was visible. This zone was probably rich in boron. As a result of laser surface modification of boronized layers, the microstructure composed of three zones: remelted zone, heat affected zone and the substrate was obtained. The microstructure of remelted zone consisted of boron-martensite eutectic. The depth of laser track (total thickness of remelted zone and heat affected zone) was dependent on laser parameters (laser beam power density and scanning laser beam velocity). The microhardness of laser remelting boronized layer in comparison with diffusion boronized layer was slightly lower. The presence of heat affected zone was advantageous, because it allowed to obtain a mild microhardness gradient between the layer and the substrate. K E Y W O R D SBoronized layer Laser remelting Microstructure Microhardness

The Effect of Varying Parameters of Laser Surface Alloying Post-Treatment on the Microstructure and Hardness of Additively Manufactured 17-4PH Stainless Steel

“…This is primarily attributed to its high impact on the modification and evolution of the surface microstructure, which results in a significant improvement of hardness and wear resistance of a developed surface layer. Consequently, surface laser alloying is widely used not only for different stainless steels, such as 1.4550 [12], 17-4PH [14], and 316L [16,17], but also for a variety of other steels, for example, 41Cr4 steel [18], C45 steel [19], 145Cr6 tool steel [20], Vanadis-6 tool steel [21,22], and so on. The use of amorphous boron is important in laser surface alloying, and this has been confirmed in the above-cited works and some others [23,24].…”