Cast Iron Laser Cleaning

Cast iron presents two distinct laser cleaning challenges: differential absorption from graphite flakes and porosity that traps contaminants below the ablation plane. Compressive strength of 830 MPa, combined with low fracture toughness, means the material responds well to multi-pass approaches and poorly to aggressive single-pass fluence. Graphite content varies by grade — gray iron flakes absorb most aggressively, ductile iron nodules far less — making grade identification useful before dialing in parameters. Pulsed 1064 nm fiber lasers at 50–80 W with scan speeds above 400 mm/s deliver consistent results on rust, scale, and foundry residue without inducing thermal cracking.