Corrosion behaviour of hardened grey cast iron with continuous-wave infrared laser

Grey cast iron is employed under chemically and physically harsh conditions. Laser hardening is used to improve the material mechanical properties. The corrosion behaviour of laser hardened cast iron, however, needs to be studied in detail. This study is focused on the assessment of the hardness and corrosion resistance of the laser hardened grey cast iron. Laser hardening was conducted with a continuous-wave (CW) near infrared fibre laser. The corrosion evaluations were carried out with electrochemical analysis techniques. The laser hardened samples with 25 % scan overlap exhibited higher corrosion resistance and hardness than the as-received grey cast iron specimens. • The laser hardened zone can be designed by varying the laser parameters. • Laser hardened samples at 25 % overlap are the hardest. • The corrosion mechanisms evolution of grey cast iron is strongly influenced by graphite flakes. • Laser hardened samples with 25 % overlap is nobler than as-received grey cast iron. • The cast iron corrosion resistance is improved by the laser hardening process at 25 % overlap.