| Rapid heat treatment has been applied to AISI H13 hot work tool steel for improving the mechanical properties, especially strength and toughness. Experimental result showed that the yield strength was increased by 10.7%, the ultimate tensile strength was increased by 12.6% and fracture toughness (Kc) values were maintained same level to compare with conventional heat treatment. It was found that the best rapid heat treatment condition was that heating rate was 21.8℃/sec, holding time was 60 sec at austenitizing temperature. It is believed that the improvement of mechanical properties, especially strength, was due to the dispersion strengthening of fine carbides precipitates within the lath martensite matrix. |
|
