Laser Surface Remelting Of Gray And Nodular Irons

摘要

The procedure of laser surface remelting has recently been increasingly used on products from gray and nodular irons for modifying the surface layer. By this procedure it is possible to achieve a very high wear resistance of both kinds of irons which can be compared with the wear resistance of surface hardened heat-treatable steels. Since in laser remelting the surface or surface layer is heated above the melting point temperature, greater depth of the austenite transformation in the material is achieved, which contributed to the formation of a modified layer deeper than that obtained by conventional hardening procedures. The experimental part of the study consisted of measurement of the size of the remelted and hardened layer and microhardness measurements in depth. The components of the laser-modified trace were additionally verified by X-ray diffraction. To investigate the residual stresses laser surface remelting, the size and variation of residual stresses were measured as a function of the modified layer depth.