Resumen

KARTHIKEYAN, S. et al. An investigation on laser shot peened surfaces. J. appl. res. technol [online]. 2022, vol.20, n.5, pp.554-563.  Epub 31-Jul-2023. ISSN 2448-6736.  https://doi.org/10.22201/icat.24486736e.2022.20.5.1375.

The present work is focused on the influence of zinc trivalent plating on laser shot peened AISI 304 stainless steel samples to improve the corrosion resistance of the steel surface. AISI 304 steel samples were heat treated by annealing and polished to perform Laser Shot Peening (LSP) process using Nd-YAG laser functioning at a pulse interval of 10ns with different energies of 200 mJ, 300 mJ and 400 mJ on each sample. The highest magnitude of compressive residual stresses is induced using the pulse density of 2500 pulses/cm2. The laser treated sample was characterized by surface hardness using Vickers micro hardness test and surface morphology using an optical microscope and SEM analysis. The surface hardness of the sample is increased by increasing laser energy. The prepared zinc trivalent is plated using electro deposition on the laser treated surface by maintaining current between 1.5 to 4 amps/Dm2, and temperature between 20 to 40 deg C. MAHR’s roughness tests were performed to find the surface roughness of the sample. The surface roughness has drastically increased on zinc- coated samples compared to samples without coating. The Vickers micro hardness test conducted on zinc trivalent plated sample revealed the increase in hardness value of 200 mJ by 24% compared with 200 mJ sample without coating. SEM and EDAX were carried out to know the changes occurred in the chemical composition of the samples before and after coating.

Palabras llave : AISI 304 austenite; annealing; laser shot peening; SEM analysis; Vickers micro hardness; zinc trivalent plating; MAHR roughness.

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