Enhancementthe microstructuresand corrosion resistance of low carbon steel using laser surface treatment


  • Dalya H. Abbas, Dina Raheem, Abbas S. Alwan


The effects of laser surfaces hardening on microstructures and corrosion characteristic of low carbon steel grade AISI1008 is present in this paper which is widely used in the components petroleum and fertilizers manufacturing. Scan laser beam of CO2 was done with parameter of 10.6 µm wavelengths, 3.5, 4 and 4.5 Kw power, and 3m / min scan speed and 4 mm laser beam diameter. Laser surface hardening process includes three stages are heating, holding and rapid cooling to modify the microstructure by phases change. The microstructures of samples is achieved under the optical microscope and X-Ray examination to identify the phase’s transformation. Scan electron microscopy was investigated for the surface metallurgy after laser treated. Surface hardening values was obtained by Digital Vicker Hardness test. Corrosion experimentally done by exposure of low carbon steel samples in a sulfuric acid (H2SO4) solution and corrosion test carried out using the electrochemical corrosion cell and measured by Tafel extrapolation method. Results show that the laser surface hardening effect to modification and improves the low carbon steel structures by formation of a hard lath martensitic phase and has a higher hardness than untreated sample. Also corrosion results refer to obtained a better corrosion resistances by decreasing of (Icorr) after laser surface hardening.
Keywords: CO2 laser , laser hardening, microstructure, Corrosion resistance, Martensite.