Effects of Carbon and Boron on Structure and Properties of Austenitic Stainless Steel Coatings Fabricated by Laser Remanufacturing

The coatings are fabricated using austenitic stainless steel powder with various contents of carbon and boron via laser remanufacturing technique. A new synchronous lateral powder feeding device is adopted to avoid surface oxidation of molten pool. The authors find that the strength can be increased but plasticity is decreased of with the rise of boron content due to the formation of lamellar borides phase structures, which are very brittle and have high hardness. In addition, the authors also find that the tensile strength and hardness are enhanced by increasing the content of carbon, while the plasticity is deteriorated due to the formed carbide in the grain of the austenitic stainless steel coating.