Experiments of laser transformation hardening were performed with various process parameters on the surface of ductile
cast iron block, which is often used for vehicle body. The distribution of microhardness along the case depth direction
and the variation of microstructure of hardened track were investigated. Wear test was carried out using a
ball-on-flat-type wear-test machine. The results indicate that the hardened layers after the laser surface hardening
treatment have excellence wear resistance. It is seen that the surface hardness of ductile cast iron blocks increases greatly
at suitable values of process parameters in laser transformation hardening, which satisfies the vehicle dies.