Effect of laser surface melting on the corrosion resistance of chromium-plated 9Cr-1Mo ferritic steel in an acidic medium

摘要: 9Cr-1 Mo ferritic steel forms an integral part of some the nuclear power generating industries where it is used as steam material. Its corrosion resistance could be further improved by employing a chromium coating over it. However, this has been found to unsatisfactory owing microcracks present in coating. Laser surface melting (LSM) effectively not only remove these but also form better corrosion-resistant modified without affecting bulk properties Studies were carried out on laser melted chromium-plated 9Cr-1Mo steel. The specimens with deposit thicknesses ranging from 30–70 μm prepared and then irradiated. Optical microscopic studies cross-sections revealed average laser-melted thickness around 0.1–0.5 mm, depending upon irradiation parameter used. Aqueous behaviour was studied anodic polarization 1N H2SO4 medium. Anodic experiments for after repolishing same specimen until base metal reached. passive peak current density values, range passivity, transpassive potentials, determined at each stage polishing, compared those pure well alloy Observation data indicates that beneficial raising aqueous such chromium-coated steels, level comparable metal.