Laser surface alloying of carbon steel and α-Fe with CrB2

Abstract A continuous wave, 2.5. kW CO 2 laser was used to surface alloy AISI 1045 steel and α-Fe with CrB 2 by the powder injection method. CrB 2 particles (100–150 μm size) were injected into the molten bath of the substrate. The particles were partially dissolved in the bath, forming a melted layer of Fe-Cr-B-C. The solidification resulted in the formation of iron borides and undissolved in the SAE 1045 steel. The hardness was high 1250 HV in both cases, caused mainly by the borides. The overlap of the laser passes did not affect the hardness distribution throughout the alloyed layer. The structure and properties of the layers were studied using X-ray diffraction, Auger electron spectroscopy, scanning electron microscopy and optical microscopy.