TY - JOUR AU - Amado, J. M. AU - Ávarez, C. AU - Nicolás, G. AU - López, A. J. AU - Pérez, J. A. AU - Ramil, A. AU - Saavedra, E. AU - Sanesteban, J. AU - Tobar, M. J. AU - Yáñez, A. PY - 2004/10/30 Y2 - 2024/03/28 TI - Steel phase transformation in the CO2 laser hardening process JF - Revista de Metalurgia JA - Rev. metal. VL - 40 IS - 5 SE - Articles DO - 10.3989/revmetalm.2004.v40.i5.289 UR - https://revistademetalurgia.revistas.csic.es/index.php/revistademetalurgia/article/view/289 SP - 365-368 AB - Hardening processes of steel are very dependent on the heating and cooling rates, in both cases high rates are needed. In the laser hardening the power density of the laser beam is responsible of the fast heating of the material; fast cooling is achieved due to the heat conduction from the region being treated to the bulk of the workpiece. Within this work thermal cycles are determined with a Finite Element Model which computes the temperature of the material during the laser treatment. For the prediction of the hardening IT diagrams are applied, isothermal steps are connected with constant volume fraction steps; the content of each phase is computed in the framework of the Johnson-Mehl and Avrami law. During the cooling process, a similar procedure is applied but now using TTT diagrams. Model validation is done comparing, on a local basis, microhardness measurement on a treated workpiece with the martensite concentration extracted from the model. ER -