INFLUENCE OF LASER HARDENING ON THE TRIBOLOGICAL PROPERTIES OF A PERLITIC CAST IRON FOR HOT ROLLS

• Published in: Tecnologia em Metalurgia, Materiais e Mineracao Vol. 20101124; pp. 244 - 255
• Main Authors: Pellizzari, M, De Flora, M G, Tremea, A, Vincente, A Fernandez, Omit, T, Heason, C, Gonzalez, J R, Prego, A Fuentes, Gouveia, H
• Format: Journal Article
• Language: English
• Published: 01.01.2010
• Subjects: Abrasion; Abrasion resistance; Disks; Hardening; Lasers; Rolls; Tribology; Wear resistance
• ISSN: 2176-1515

The wear behaviour of a laser hardened perlitic cast iron (PCI) for hot rolls is evaluated. The role of the higher hardness pertaining to a fresh untempered martensite microstructure obtained by laser hardening is examined in view of the complex wear mechanism operating during laboratory test, including abrasion, triboxidation and adhesion. Dry rolling-sliding wear tests have been carried out using a disc on disc configuration involving the contact between the sample and a C40 plain carbon steel counterpart. In order to modify the relative contribution of abrasion and triboxidation test at different temperature were carried out. The tests at low temperature (without auxiliary heating of the C40) demonstrate that laser hardening is a valuable method to increase wear resistance. At higher temperature (C40 induction heated at 700 degree C) the relatively higher contribution of triboxidation than abrasion allows just a minor improvement to be observed. The formation of wear protective oxide layer on the soft metallic matrix of base material causes a relatively higher resistance. This phenomenon is not supported by a the hard martensitic matrix of laser treated samples.