Improvement The Corrosion Behavior an‎d Wear Characteristics Of Aisi 304 Stainless Steel By Using Nd -Yag Laser Surface Treatment

This article aimed to study the effect of pulsed laser surface melting (LSM) on the corrosion behavior and wear characteristic of AISI 304 stainless steel which are used widely in medical and food equipment. Laser beam of Nd-YAG (neodymium – doped yttrium aluminum garnet Nd: Y3Al5O12) was done with parameters of 0.8 mm spot size, 10 mm/sec. travel speed, 2 ms pulse duration, 1-3 Hz pulse repetition rates (frequencies ), 1064 nm wavelengths and 4J fixed energy. Surface treatment process include surface melting by rapid heating of the materials surface and followed by fast cooling to modify the microstructure and phase change of surface metal. The microstructure of samples were performed by using the optical microscope and confirmed by X-ray diffraction analysis to identify the phase’s transformation after laser treatment. Scan electro microscopy was considered in investigated the surface morphology before and after laser treatment. Surface hardening values was obtained by MicroVicker test. Corrosion test was carried out using the electrochemical corrosion cell and measured by Tafel extrapolation method of 304 stainless steel in a chloride acid (HCl) solution at 37 0C. Results shows that the treated samples by laser surface melting have a higher hardness and wear resistance than untreated sample. Also corrosion results indicated that the treated samples were a higher pitting corrosion resistance than untreated samples.