Feasibility of laser surface treatment of pearlitic and bainitic ductile irons for hot rolls

摘要: Abstract The effects of laser surface treatment on the microstructure, crackability and stresses generated hardened layers produced in several ductile cast iron materials were investigated. Two kinds alloys having pearlitic (SGP) acicular (SGA) matrix microstructures selected. Hardened with thicknesses ranging from 1.5 to 2.5 mm obtained by means remelting (LSRm) or hardening (LSH). Thermal upon processing have been estimated a simple thermal model. For energy densities delivered onto material at above 40 J/mm 2 , extensive cracking was developed SGA SGP irons due contribution stresses. By lowering density, crack formation avoided only. At low densities, is controlled generation transformational excessive austenite retention. An increase temperature alloying content gave rise an retained lower bainite remelted zone heat affected zones, respectively. K C fracture toughness Fe 3 carbides embedded matrixes measured nano-indentation technique. Fracture cementite slightly higher than irons, which can help reduce LSH layers.