Microstructure, mechanical properties and corrosion resistance of laser surface melted EN353 low carbon low alloy steel

The efficacy of laser surface modification of EN353 low carbon low alloy steel is studied and discussed. The high power diode laser (HPDL) treated layers were characterised by means of high resolution scanning electron microscopy (HRSEM), and X-ray diffractometer (XRD). The mechanical properties like hardness, wear and corrosion resistance were studied. The hardness profile of the laser modified cross-sectional layer was determined by using Vickers hardness tester. It was found that the microhardness improved to as high as 493 HV as compared to 215 HV of the substrate material. The laser surface melting by the HPDL resulted of martensite and bainite microstructure in low carbon low alloy steel. XRD phase analysis indicated the formation of martensite, Fe-Mn-C, Fe-Cr-C and M23C6 carbide phases at near surface regions of laser treated samples. The wear resistance of the laser surface melted EN353 steel was also found to be increased. Potentiodynamic electrochemical corrosion method revealed an improved corrosion resistance in the laser treated layers.