Laser gas assisted treatment of AISI H12 tool steel and corrosion properties

• Dense structure consisting of fine grains and nitride species is formed at the surface.
• Laser treated depth layer extends uniformly 50 µm below surface.
• Laser treatment improves corrosion resistance of the surface.
• Pits sites are shallow and no secondary pitting is observed.

Laser gas assisted treatment of AISI H12 tool steel surface is carried out and the electrochemical response of the laser treated surface is investigated. Morphological and metallurgical changes in the treated layer are examined using a scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction. Potentiodynamic polarization tests are carried out for untreated and laser treated specimen in 0.2 M NaCl solution at room temperature. It is found that the laser treated AISI H12 workpiece surfaces exhibit higher corrosion resistance as compared to untreated specimen as confirmed by lower corrosion rate, higher pitting potential, and lower passive current density.