J. Phys. IV France 01 (1991) C7-81-C7-86
FATIGUE BEHAVIOR OF PEARLITIC S.G. CAST IRONS AFTER LASER SURFACE HEAT TREATMENTSY. GUAN1, D. PANTELIS1, D. CHAMBOLLE1, S. PARENT-SIMONIN2 and Ph. POUPEAU1
1 Laboratoire MSS/MAT, URA CNRS n° 850, Ecole Centrale de Paris, Grande Voie des Vignes, F-92295 Châtenay-Malabry cedex, France
2 Centre Technique des Industries de la Fonderie, Division Fontes, 44 av. de la Division Leclerc, F-92312 Sèvres cedex, France
The laser transformation hardening does not improve the fatigue resistance of two pearlitic S.G. cast irons, using as surface preparation BN coating, sandblasting or phosphatation. On the treated surface, the initial pearlite is transformed into martensite. In the treated layer, further under the treated surface, a martensitic microstructure with traces of incompletely dissolved cementite can be observed. A bidimensional numerical heat transfer model has been developed for surface transformation determination. This model allows the use of temperature dependent thermophysical properties, spatial energy distribution of the laser beam and convective heat losses. The agreement between the calculated results and the experimental results depends on the value of the ratio [MATH].
© EDP Sciences 1991